World Agriculture Vol.2 No.1 (Spring 2011)

Front

6/4/11

14:52

Page 1

Inside Front

29/9/10

15:35

Page 1

01

6/4/11

12:15

Page 1

editorial World Agriculture Editorial Board

Published by Wharncliffe Publishing, 47 Church Street, Barnsley, South Yorkshire S70 2AS, UK

Patron Sir Crispin Tickell GCMG, KCVO Chairman Professor Sir Colin Spedding CBE, MSc, PhD, DSc, CBiol, Hon FSB, FRASE, FIHort, FRAgS, FRSA, Hon Assoc RCVS, Hon DSc Agriculturalist Deputy Chairman & Editor Dr David Frape BSc, PhD, PG Dip Agric, CBiol, FSB, FRCPath, RNutr Mammalian physiologist Assistant Editors Robert Cook BSc, CBiol, MSB, ARAgS (UK) Plant pathologist and agronomist Ben Aldiss BSc, PhD, CBiol, MSB, FRES (UK) Ecologist, entomologist and educationalist Members of the Editorial Board Professor Pramod Kumar Aggarwal B.Sc, M.Sc, Ph.D. (India), Ph.D. (Netherlands), FNAAS (India), FNASc (India) Crop ecologist Professor Phil Brookes BSc, PhD, DSc (UK) Soil microbial ecologist Professor Andrew Challinor BSc, PhD (UK) Agricultural Meteorologist Professor J. Perry Gustafson BSc, MS, PhD (USA) Plant Geneticist Professor Paul Jarvis FRS, FRSE, FRSwedish Soc. Agric. & Forestry (UK) Silviculturalist Professor Brian Kerry MBE, BSc, PhD (UK) Soil microbial ecologist Professor Glen M. MacDonald BA, MSc, PhD (USA) Geographer Professor Sir John Marsh CBE, MA, PG Dip Ag Econ, CBiol, FSB, FRASE, FRAgS (UK) Agricultural economist Professor Ian McConnell BVMS, MRVS, MA, PhD, FRCPath, FRSE (UK) Animal immunologist Dr Christie Peacock BSc, PhD, FRSA, FRAgS (UK) Tropical Agriculturalist Professor RH Richards C.B.E., M.A., Vet. M.B., Ph.D., C.Biol., F.S.B., F.R.S.M., M.R.C.V.S., F.R.Ag.S (UK) Aquaculturalist Professor Neil C. Turner FTSE, FAIAST, FNAAS (India), BSc, PhD, DSc (Australia) Crop physiologist Dr Roger Turner BSc PhD, MBPR (UK) Agronomist Professor John Snape BSc PhD (UK) Crop geneticist Editorial Assistants Advisor to the board Dr Philip Taylor BSc, MSc, PhD John Bingham Ms Sofie Aldiss BSc CBE, FRS, FRASE, ScD Michael J.C. Crouch BSc Crop geneticist Rob Coleman MSc

WORLD AGRICULTURE

1

Inside Front

19/3/10

11:07

Page 1

03

8/4/11

13:14

Page 1

contents

In this Issue ...

Appointments:

The Editorial Board is very pleased to welcome to the Board Professor Pramod Kumar Aggarwal. Professor Aggarwal is based in New Delhi

Objectives and functions of World Agriculture Editorials: The ‘Organics’ Debate

Professor Sir Colin Spedding, Dr David Frape & Robert Cook Food for thought on farming systems Dr David Frape, Robert Cook

Scientific: Nitrogen cycle and world food production Professor Vaclav Smil The scale for managing production vs the scale required for ecosystem service production Professor Tim G. Benton, Professor AJ Dougill, Professor EDG Fraser & DJB Howlett Pesticide toxicity and public chemophobia: how toxic are modern-day pesticides?

Dr David Hughes Feeding the World: A contribution to the debate Professor Keith WT Goulding, Professor Anthony J Trewavas, and Dr Ken E Giller

Economic & Social: Organic Agriculture: The farming system fit for the 21st Century Dr Isobel Tomlinson Integrated farm management; reducing the impact of agriculture and maintaining output – the example of LEAF in the UK Caroline Drummond

Books and Report Reviews: The Foresight Report, The Future of Food and Farming: Challenges and choices for global sustainability Reviewed by Professor Sir John Marsh The Truth about Organic Foods; Author, Alex Avery (Henderson Communications, 2006; 230 pp, paperback. (ISBN 9780978895204). Available from Optima Excel, Pen-y-Lan, Tregoed, Brecon, Powys, LD3 0SS, UK Reviewed by Professor Paul Davies Reviewed by Dr Jonathon Harrington

Publisher’s Disclaimer No responsibility is assumed by the Publisher for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise or from any use or operation of any methods, products, instructions or ideas contained in the material herein.

Although all advertising material is expected to conform to ethical standards, inclusion in this publication does not constitute a guarantee, or endorsement of the quality or value of such product by the Publisher, or of the claims made by the manufacturer.

Instructions to contributors Potential future titles Return slips WORLD AGRICULTURE

3

04

6/4/11

12:17

Page 1

World Agriculture: A peer-reviewed, scientific review journal directed towards opinion formers, decision makers, policy makers and farmers

objectives and functions of the Journal The Journal will publish articles giving clear, unbiased and factual accounts of development in, or affecting, world agriculture. Articles will interpret the influence of related subjects (including climate, forestry, fisheries and human population, economics, transmissible disease, ecology) on these developments. Fully referenced, and reviewed, articles by scientists, economists and technologists will be included with editorial comment. Furthermore, a section for “Opinion & Comment” allows skilled individuals with considerable experience to express views with a rational basis that are argued logically.

References to papers that have been subject to peer-review will not be mandatory for this section. From time to time the Editor will invite individuals to prepare articles on important subjects of topical and international concern for publication in the Journal.

Articles will be independently refereed. Each article must create interest in the reader, pose a challenge to conventional thought and create discussion. Each will: 1) Explain likely consequences of the directions that policy, or development, is taking. This will include interactive effects of climate change, population growth and distribution, economic and social factors, food supplies, transmissible disease evolution, oceanic changes and forest cover. Opinion, in the “Opinion & Comment” Section must be based on sound deductions and indicated as such. Thus, an important objective is to assist decision-makers and to influence policies and methods that ensure development is evidence-based and proceeds in a more “sustainable” way. Without a clear understanding of the economic causes of the different rates of agricultural development in developing and developed countries and of migration rates between continents rational policies may not be developed. Hence, the role of economics must be understood and contribute an important part in the discussion of all subjects.

2) Provide independent and objective guidance to encourage the adoption of technical innovations and new knowledge.

3) Discourage false short-sighted policies and loose terminology, e.g. “organic”, “genetically modified”, “basic”, “sustainable”, “progress” and encourage informed comment on policies of governments and NGOs. 4) Indicate the essential role of wild-life and climate, not only in the context of agricultural and forestry development, but by maintaining environmental balance, to ensure the sustenance and enjoyment of all.

5) Summarise specific issues and draw objective conclusions concerning the way agriculture should develop and respond in the location/region of each enterprise, to evolving factors that inevitably affect development.

6) Promote expertise, for advising on world agricultural development and related subjects.

7) Allow interested readers to comment by “Letters to the Editor” and by “Opinion & Comment” columns.

8) Provide book and report reviews of selected works of major significance.

9) To include a wide range of commercial advertisements and personal advertisements from advisors and consultant groups.

Near drought conditions challenge spring soybean crops. (Glycine max)

4

WORLD AGRICULTURE

05

6/4/11

12:18

Page 1

editorials

The ‘Organics’ Debate Colin Spedding, David Frape & Robert Cook e make no apology for publishing more articles and an editorial on the general subject of ‘organic’ farming in this issue of World Agriculture. The subject gives rise to extensive and often polarised discussion, especially in Europe and the developed world generally.

W

that, if one ‘side’ attacks the other, those attacked (particularly if the attack is felt to be unfair or inaccurate) feel obliged to respond. This is especially so if the attacks are made publicly and designed to influence the public and, even more so, if there are potentially adverse economic consequences.

The reasons for the popularity of produce from organic systems often derive from the belief that they are better for the environment, or have health or other personal benefits. This is often a genuine response to real concerns about the impacts of agriculture on environmental degradation, and/or a belief that synthetic pesticides and fertilizers have adverse effects on health. Obviously, there is nothing intrinsically wrong with such views; they represent a caring consideration for the planet or a concern for one’s own health. They may also be related to the luxury of having enough to eat and thus the ability to select products which may be relatively more expensive at point of sale.

The world faces many problems and challenges, most of which derive from an ever increasing human population and the implicit pressure on resources and the environment. There is an overwhelming imperative to develop agricultural systems which reduce overall greenhouse gas emissions and consistently increase output per unit area. These imperatives must guide decision-making about approaches for sustainable systems.

Nevertheless, it is extremely unlikely that valid generalisations, of the form “organic/conventional farming is better, worse, healthier, safer or better for the ‘environment’’’, can be formulated. This conclusion is drawn from the fact of the wide range of agricultural products and the great variety of soil, land and weather conditions under which they are grown.

Some generalisations related to economic issues and resource use (e.g. energy and land use or manpower) can, however, be made, provided that they are related to specified products or processes. There is therefore, no such thing as an ‘organic’ system or a ‘conventional’ system, since there are many different ways of producing the same product. There are, however, characteristically different approaches to farming.

The main reason for the current antagonism between approaches is

There is a view, to which the WA editorial board subscribes, that the problem is too serious for effort to be wasted arguing about the pros and cons of beliefs. We support a more positive debate which involves identifying features of approaches to farming that can usefully be applied to alternative systems used in comparable conditions. By integrating these features, the ‘organic’ and ‘conventional’ systems become complementary, with each learning and benefiting from the research, technology and experiences of the other.

Simple examples might be: The organic sector could identify methods of reducing use of herbicides/pesticides that could be used in conventional systems.

Conventional practitioners could identify methods/technology that would raise productivity or reduce costs in organic systems.

Developing ways in which the intrinsic heterogeneity of organic systems improve farmland biodiversity that can be applicable to conventional systems.

In this way a clear distinction can be made between differences in view, approach or practice, which are often emotional, unproven (or even unprovable) assertions, to the identification of differences based on accepted facts.

Determining the basis of any approach to farming on what might be seen as an arbitrary set of decisions to use or not use a particular approach or technology is not necessarily helpful to the constructive debate and decision making process needed to secure adequate long term agricultural production.

Whilst valuable lessons may be learned from practice an assertion about a method of production is of little value without reliable evidence for its adoption. Factual evidence for improved methods can be established only by the adoption of the scientific method.

The application of an improved method should be limited to the range of conditions under which it has been established. This limitation involves technical and economic decisions of great variety, as no two regions, farms or even fields are identical and the economy of production in each of these is continually changing.

Nevertheless, so long as the evidence is reliable it can be applied more widely and over time. For example, if one production method is thought to increase the output of a product per ha, so releasing other areas for wildlife, improving bio-diversity, but is anticipated to cause a greater rate of nitrous oxide production in the cultivated area, how is this to be assessed?

If there is reliable evidence about what is likely to occur with the new approach in each of these areas, then a rational decision can be taken. The procedures adopted can vary over time, depending on economic and other circumstances, but those procedures should always be based upon the factual evidence previously established.

WORLD AGRICULTURE

5

06

6/4/11

12:19

Page 1

Lichens depend upon a symbiotic relationship with algae for the fixation of atmospheric nitrogen

6

WORLD AGRICULTURE

07

6/4/11

12:19

Page 1

editorials

Food for thought on farming systems David Frape and Robert Cook

T

he nitrogen-cycle (N-cycle), discussed in detail in this Issue, is a key to the difference between “organic” and so-called “conventional” farming. Synthetic Nfertilisers depend for their production upon the Haber process for the fixation of atmospheric N in the form of ammonia by reaction with hydrogen gas. Despite the fact that 78.1% of the air we breathe is N, this gas is relatively unreactive because the molecule (N2) is held together by a strong triple bond. Hence, the process requires a considerable amount of energy. In fact, 3–5% of world natural gas production, is consumed in the Haber process; about 1–2% of the world's annual energy supply (Smil 2001). The Haber process now produces 100 million tonnes of N fertiliser per year.

Nevertheless, this production is estimated to be responsible for sustaining one-third of the Earth's population (Hager, 2008). The limiting factor is food energy, in the form of net energy for maintenance, physical work, growth and reproduction. If all world farming was organic it has been estimated that it could support a population of ca 4 billion (Benton et al., Goulding et al., Smil, all this Issue); but by 2050 the population is expected to exceed 9 billion. Clearly, the provision of enough food for a population of this size cannot be achieved either by organic farming, or by current conventional production, restricted to the present total agricultural area and

current technologies.

To meet their desires, especially for a high meat diet, the developed world imports exotic and other foodstuffs from developing countries, in some cases where many in those countries have insufficient food to sustain a healthy life themselves. The articles in this issue seem to indicate that meeting the needs of an increasing population under an organic system would entail the destruction of forested and other areas of natural habitat.

This would partly compensate for the loss of sequestered carbon caused by the Haber process, but would, in turn, lead not only to a loss of vast forests, a valuable carbon sink, but the loss of biodiversity. The land made available is still unlikely to meet requirements, partly because most forest soils are of poor quality.

Clearly what is required, is a carefully timed and “titrated” precision use of N-fertilisers in each field of each farm so that optimum amounts are used, spatially and temporally, to maximise output and minimise inputs, taking account of the marginal and expected effects on yield.

Ideally it should incorporate the needs for adequately feeding the world and also the effects on carbon and N balances, though this is impractical at present. These balances were not previously considered in this context for without reliable knowledge of rainfall and growing conditions in each field the objective will be difficult to

achieve. A uniformly higher standard of husbandry, improved technology and precision farming is required worldwide to increase agricultural output from approximately the same total area of land, to maintain biodiversity and not to increase greenhouse gas production.

The great virtue of the organic movement is that it has focussed attention on the importance of soil quality and organic matter, features recognised by the entire farming community for more that 150 years. The importance of this has been known to the internationally famous Rothamsted Research Station since the 1850s (see this Issue).

The challenge is to increase output without further degradation of the farmed land, prevent further loss, or even to enhance, biodiversity and avoid taking more land into cultivation. This is a significant challenge which will require a comprehensive integration and exploitation of technologies from several disciplines.

Perhaps our best chance is the approach adopted by LEAF (Drummond, this Issue) which can provide the intelligent, integrated system needed, offering advantages over both the “Organic” and intensive farming systems for both output and maintaining biodiversity.

The evolution of a farming system should always be based on the most reliable evidence and experience, have a rational basis and the development should be logically argued.

References Hager, T. (2008). The Alchemy of Air. Harmony Books, New York. ISBN 9780307351784.

Smil, Vaclav (2001) Enriching the Earth: Fritz Haber, Carl Bosch, and the Transformation of World Food Production, Cambridge, MA, The MIT Press, 2001 ISBN 0-262-19449-X

WORLD AGRICULTURE

7

08

29/9/10

15:52

Page 1

09

6/4/11

12:20

Page 1

scientific

Nitrogen cycle and world food production Vaclav Smil Distinguished Professor in the Faculty of Environment, University of Manitoba, Winnipeg, CANADA. http://www.vaclavsmil.com

Summary PIn the biosphere nitrogen has the most complex cycle of all circulating elements. Its incessant reuse makes life on Earth possible. Traditional agricultures supplied limited amounts of the nutrient by recycling organic wastes and by planting leguminous crops. Only the Haber-Bosch synthesis of ammonia, first commercialised in 1913, removed this key constraint on crop productivity. Global agriculture has become steadily more dependent on synthetic nitrogenous compounds without whose applications we would not be able to produce roughly half of today’s world food.

This high, and rising, dependence exacts a considerable environmental price, as the losses of nitrogen fertilisers lead to contamination of waters, eutrophication, and excessive atmospheric deposition and emissions of a potent greenhouse gas. Inefficient use of nitrogenous fertilisers is also an obvious economic loss and a waste of natural gas, the prime feedstock and energiser of ammonia synthesis. There is no single measure that could substantially cut these losses but they can be reduced by careful agronomic management and (most effectively, but controversially) by moderate consumption of animal foodstuffs. In any case, more nitrogen will be needed to feed the additional 1.5-2 billion people that will be added to the global population before its growth levels off later in this century.

Glossary

and phosphorus (P) which results in excessive plant (principally algae) growth and decay.

Eutrophication: degradation of water quality owing to enrichment by nutrients, primarily nitrogen (N)

Life on Earth would be impossible without incessant cycling of key elements that make up biomass. Three cycles – those of carbon, nitrogen and sulphur – are particularly noteworthy: carbon is, of course, the dominant

Relative neglect and existential necessity

C

oncerns about rapid global warming – anthropogenic emissions of carbon dioxide (CO2) and the resulting planet-wide rise of tropospheric temperatures and alteration of carbon cycle – have come to dominate not only media attention but also scientific debates in general and environmental concerns in particular. A simple search of Google News reveals the information gap. In January 2011 the site listed more than 700 items for the carbon cycle but fewer than 90 items for the nitrogen cycle. I would argue that the real public awareness gap is much greater than this, an order of magnitude difference, as the comparison includes

Troposphere: lowest layer of the earth’s atmosphere, below the stratosphere.

Anthropogenic: produced by human

Abbreviations Gt, gigatonne, or 10 Introduction

activity.

9

12

6

tonnes, 10 kg. Mt, megatonne, or 10 tonnes.

constituent of all living matter (typically 45-50% of dry weight). Proteins cannot be made without nitrogen, and disulphide bridges make the proteins three-dimensional, ready to enter into myriads of enzymatic reactions. Proteins also act as signalling and many references to papers published in scientific journals whose content will never become widespread public knowledge.

This attention disparity is curious because human interference in the nitrogen cycle is incomparably more massive than our perturbance of the carbon cycle. This is because most of the disruption is due to that most fundamental of all energy conversions, the production of food. In absolute terms anthropogenic emissions of carbon from fossil fuel combustion (nearly 9 Gt C/year) are less than 10% of the annual carbon uptake by terrestrial photosynthesis. In contrast, human activities (fertilisers, planting of legumes and emissions of nitrogen oxides from combustion) now release about as much reactive nitrogen

structural compounds. The three cycles are remarkable because of their complexity, the importance of microbes in their functioning and because the cycled elements are transported by both air and water and hence able to move far away from their sources. (about 150 Mt N) as is formed by natural processes (biofixation, lightning). There is no possibility that we will be able to produce food without nitrogen. Therefore, the nitrogen cycle and human interference in its functioning should get at least as much attention as our current (and I would argue exaggerated) preoccupation with global climate change.

Understanding the cycle Studies of the nitrogen cycle go back to the period of pioneering research that laid the foundation of modern life sciences during the 19th century (Smil 2001). Justus von Liebig, one of the founders of organic chemistry, formulated the law of the minimum (plant growth is limited by the

WORLD AGRICULTURE

9

10

6/4/11

12:20

Page 1

scientific ‘With average crop yields remaining at the 1900 level the crop harvest in the year 2000 would have required nearly four times more land and the cultivated area would have claimed nearly half of all ice-free continents’ element that is present in the soil in the least adequate amount), published the first concepts of global biospheric cycles and recognised the importance of nitrogen in crop production by contrasting it with forestry: Agriculture differs essentially from the cultivation of forests, inasmuch as its principal object consists in the production of nitrogen under any form capable of assimilation; whilst the object of forest culture is confined to the production of carbon (Liebig 1840).

Jean-Baptiste Boussingault (18021887) found that the nutritional value of fertilisers is proportional to their nitrogen content and demonstrated that legumes can restore nitrogen to the soil. John Bennet Lawes (18141900) and Joseph Henry Gilbert (1817-1901) initiated the first continuous experiments with crops receiving different amounts of fertilisers and demonstrated, beyond any doubt, that nitrogen fertilisers (followed by phosphates) are the key to higher grain crop yields. In 1877 Théophile Schloesing (1824-1919) proved the bacterial origins of nitrification, in 1885 Ulysse Gayon (1845-1929) and his assistants closed the cycle by finding denitrifying bacteria that can reduce nitrates and, via NO and N2O, return N2 to the atmosphere. In 1886 Hermann Hellriegel (1831-1895) and Hermann Wilfarth (1853-1904) solved the mystery of leguminous nodules as the sites where biofixation (conversion of atmospheric N2 into NH3) takes place.

The nitrogen cycle (Fig 1) and its key role in agricultural productivity were thus well understood by the end of the 19th century and this very knowledge led to growing concerns about future harvests: where will the countries with growing populations and with rising demand for better nutrition get the additional nitrogen needed to sustain higher crop yields?

None of the options available during the 1890s could solve the challenge.

Traditional recycling of organic wastes could supply only a limited amount: the nitrogen content of these wastes is

10

WORLD AGRICULTURE

inherently low, typically less than 0.5% in cereal straws, 2-4% in animal manures, and nitrogen losses before and after their application are high.

These facts necessitate massive labourintensive applications of farmyard manures in amounts commonly in excess of 10 t/ha. Bird guano has a higher N content but its resources were limited. Chilean nitrates contain about 15% N but their exports could satisfy only a small share of the potential global demand. Moreover, the first synthetic products, ammonium sulphate from coking and synthetic cyanamide (CaCN2) were also available only in limited quantities and were rather expensive.

Synthetic fertilisers and food production All this changed with unexpected rapidity just before the outbreak of World War I. In early July 1909, after years of intensive experiments, Fritz Haber (1868-1934) succeeded in synthesising ammonia from its elements with the help of an ironbased catalyst (Smil 2001; Stoltzenberg 2004). Within four years of this laboratory bench demonstration, BASF, Germany’s largest chemical company, had a commercial process ready: Carl Bosch (1874-1940) was the engineer responsible for this remarkable achievement. Haber-Bosch synthesis of ammonia made it possible to massproduce inexpensive nitrogenous fertilisers but their use remained limited during the inter-war years.

Ammonia synthesis took off only after World War II, its global output rising from 3.7 Mt N in 1950 to 85 Mt N by the year 2000 and to about 133 Mt in 2010, with about 75% of the total used as fertiliser (Table 1). European, North American and Japanese agricultures were the first beneficiaries of inexpensive nitrogenous fertilisers.

By the 1960s rising nitrogen application made it possible to realise high yields of new short-stalked wheat and rice cultivars planted in lowincome countries of Asia and Latin

America. Eventually China, the world’s most populous country, became, and remains, the largest user as well as the largest producer of synthetic nitrogen (FAO 2011).

The role of synthetic nitrogenous fertilisers – initially a variety of compounds, most recently dominated by urea – is perhaps best illustrated by comparing typical grain yields in 1900 with the year 2000. In 1900 traditional cultivars received virtually no synthetic nitrogen fertilisers, whereas in the year 2000 high-yielding cultivars were grown with an adequate nitrogen supply (Smil 2011). This, together with advances in breeding (producing short-stalked cultivars with high harvest indices) and chemical protection (herbicides and pesticides) has more than tripled the average US wheat yields during the 20th century and the analogical multiples are 5.8 for France and 3.8 for China. in the USA average yield of corn, the country’s most important field crop, rose more than five-fold during the 20th century, from 1.6 t/ha to 8.5 t/ha. Japan’s average rice yield, already relatively high in 1900 (2.2 t/ha), increased nearly three times before reaching a plateau between 5.8-6.5 t/ha during the 1980s. Nationwide yield maxima for rice are 6-8 t/ha, in East Asia and California.

With average crop yields remaining at the 1900 level the crop harvest in the year 2000 would have required nearly four times more land and the cultivated area would have claimed nearly half of all ice-free continents, rather than under 15% of the total land area that is required today (Smil 2011). A different perspective has been quantified by Burney, Davis and Lobell (2010): they calculated that between 1961 and 2005 increased crop yields had a net effect of avoiding emissions of up to 161 Gt C. At the same time, these high levels of production have made modern cropping highly dependent on constant inputs of nitrogen (Table 1) supplemented by phosphorus, potassium and micronutrients.

11

6/4/11

12:22

Page 1

scientific

Fig 1 Nitrogen cycling in the global agroecosystem. Stores are shown as rectangles and flows as valves. The cycle is subdivided into its three principal environmental compartments (atmosphere, soils and waters) and all flows affected or dominated by human actions (and hence the targets of possible efficiency improvements) are shown in red while the flows mediated or dominated by bacterial metabolism are in blue. The latest available crop production, livestock and fertilizer statistics from FAO and IFA and nitrogen contents from Smil (2001) were used to calculate the stores and flows as annual averages for the period 2005-2009. Their accuracy varies from high (fertilizers, food) to poor (runoff, denitrification). Food (30 Mt N) corresponds to average global per capita daily intakes of 50 g of plant and 25 g of animal protein (excluding aquatic species). The difference between fixation and fertilizers is ammonia used as feedstock in chemical syntheses.

WORLD AGRICULTURE

11

12

8/4/11

13:16

Page 1

scientific

Plate 1: Rice fields in terraced hills of South China's Yunnan province: Asia's rice cultivation benefits from high nitrogen applications but it has generally low nitrogen use efficiency, often less than 30%, due to high leaching and denitrification losses. Photograph: Jialiang Gao Synthetic nitrogenous fertilisers now provide just over half of the nutrient received by the world’s crops; the rest comes mostly from natural and managed (leguminous crops) biofixation, organic recycling (manures and crop residues) and atmospheric deposition. Without the use of nitrogen fertilisers we could not secure enough food for the prevailing diets of nearly 45% of the world’s population, or roughly three billion people. These diets are excessive in rich countries, adequate in China, but inadequate in much of Africa. The reason for this is that about 85% of all food protein comes from cropping, whereas only 15 % is derived from grazing and aquatic catches. In China synthetic fertilisers already account for more than 60% of all nitrogen inputs (Ma et al. 2010) as they do in India (Pathak et al. 2010). By 2025 more than half of the world’s food production will depend on HaberBosch synthesis, and this share will keep rising for at least several more decades. Unfortunately, this will cause even greater nitrogen losses in the environment.

Inefficient fertilisation and its environmental impacts Low fertiliser prices and the quest for

12

WORLD AGRICULTURE

maximum yields led to steadily higher applications of nitrogenous compounds, now commonly exceeding 100 kg N/ha for the most productive wheat, rice and corn crops.

Two main factors have changed that trend: (1) higher prices, reflecting the higher cost of natural gas (after World War II methane (CH4) largely displaced coal hydrogenation as the main source of hydrogen and it also became the principal energiser of the Haber-Bosch process) and (2) concerns about intensifying environmental impacts. Inherent complexity of the nitrogen cycle and the ubiquitous roles of bacteria in its functioning present many routes for undesirable losses from an agroecosystem receiving high nitrogen applications (Bothe, Ferguson and Newton 2007).

Volatilisation, leaching, soil erosion and denitrification usually claim most of the applied nutrient. Although grain crops can recover as much as 85-90% in small-scale experiments using 15Nlabelled fertiliser (Krupnik et al. 2004), actual field recoveries are rarely above 50%. Nitrogen use efficiencies in major EU agricultures range from just 38% in France and the Netherlands to 42% in Germany and 44% in Italy (Oenema et al. 2009). In China’s paddy fields (Plate I) typical losses are

still higher: even with optimised applications they can exceed 70% and with traditional applications they can be more than 80% (Fan et al. 2007).

Consequences of these losses have been well documented (Sutton et al.

2011): leaching of nitrates into ground water, rivers, ponds and lakes; expanding dead zones in coastal ocean waters, resulting from recurrent eutrophication; atmospheric deposition of nitrates and ammonia affecting natural ecosystems; higher emissions of nitrous oxide (N2O), now the third most important greenhouse gas following CO2 and CH4. The global extent of these losses is bound to increase because at least three billion people need substantially better diets and hence higher nitrogen applications to their food crops. The need is most obvious in sub-Saharan Africa where typical fertiliser application rates are an order of magnitude below the recommended levels (Goulding, Jarvis and Whitmore 2008). Of course, our dependence on synthetic nitrogenous fertilisers could be cut if we chose to reduce our intakes of animal foodstuffs – but it will grow, as dietary transitions change the pattern of typical food consumption in the opposite direction.

13

8/4/11

13:17

Page 1

scientific Dietary transitions and demand for nitrogen Rising incomes, urbanisation and industrialisation, the higher participation of women in the labour force and decreasing size of families, has led to a universal transformation of traditional diets. These diets, dominated by a few staple cereals, legumes and tubers, are changing to diets with much lower shares of all staple foods, but with a higher consumption and greater variety of vegetables and fruits and, above all, with much higher intakes of meat, dairy products, eggs and aquatic species. While the speed of this transition has been highly country specific the eventual outcome always results in a much higher demand for nitrogen. Very few countries can secure most of the additional protein demand by grazing or by increased fish catch and the only option is a much expanded cultivation of feed crops, now globally dominated by corn and soybeans, or their import.

Inherent inefficiencies of animal metabolism mean that the countries with a high per capita meat supply have the diets with the highest nitrogen cost (that is the lowest overall nitrogen use efficiency). Spain is now the European leader with an annual supply of about 110 kg of meat/capita, while the US supply averages more than 120 kg/capita.

Moreover, the nitrogen cost is excessive in those countries where

References Bothe, H., Ferguson, S.J. and Newton, W.E. Biology of the nitrogen cycle.

Amsterdam, Elsevier, 2007. ISBN 9780444528575 Burney, J., Davis, S.J. and Lobell, D.B. (2010). Greenhouse gas mitigation by agricultural intensification. Proceedings of the National Academy of Sciences 107, 12052-12057.

Fan, M, Fan, Shihua ,L., Rongfeng, J., Xuejun L., Xiangzhong, Z., Keith, W., Goulding, T. and Fusuo, Z. (2007).

Nitrogen input, 15N balance and mineral N dynamics in a rice–wheat rotation in southwest China. Nutrient Cycling in Agroecosystems 79, 255–265.

FAO (Food and Agricultural Organization) (2011). FAOSTAT: Fertilizers. http://faostat.fao.org/site/575/default. aspx#ancor Goulding, K., Jarvis, S. and Whitmore, A. (2008). Optimizing nutrient management for farm systems.

Philosophical Transactions of the Royal Society B 363, 667-680.

Table 1: World production of synthetic nitrogenous fertilisers, 1900-2010 (all values are in Mt N/year rounded to the nearest 100,000 t)

average efficiency of fertiliser uptake by plants remains below what should be achievable by good agronomic practices. My calculations show the overall nitrogen efficiency of the global food system to be no more than 15%, the US rate is no better than about 12% (Howarth et al. 2002) and Ma et al. (2010) calculated the ratio for China’s food supply to be only about 9%.

Obviously, even relatively small reductions in the average meat consumption would have notable effects on overall nitrogen losses. But in the absence of higher meat costs, or Howarth, R.W., Boyer, E.W., Pabich, W.J. and Galloway, J.N. (2002). Nitrogen use in the United States from 1961-2000 and potential future trends. Ambio 31, 88-96.

Krupnik, T. J., Six, J., Ladha, J. K., Paine, M. J. and van Kessel, C. (2004).

An assessment of fertilizer nitrogen recovery efficiency by grain crops. In: Agriculture and the nitrogen cycle.

Assessing the impacts of fertilizer use on food production and the environment (A. R. Mosier, J. K. Syers and J. R. Freney, eds). SCOPE 65, 193–207. Washington, DC, Island Press.

Liebig, J. von. Chemistry in its applications to agriculture and physiology, p.85. London, Taylor & Walton (1840).

Ma, L., Ma, W.Q., Velthof, G.I., Wang, F.H., Qin, W., Zhang, S. and Oenema, O. (2010). Modeling nutrient flows in the food chain of China. Journal of Environmental Quality, 39, 1279-1289.

Oenema, O., Witzke, H.P., Klimont, Z., Lesschen, J.P. and Velthof, G.L. (2009).

Integrated assessment of promising measures to decrease nitrogen losses in agriculture in EU-27. Agriculture,

lower average incomes, this is not a popular course to follow. This leaves us with better agronomic management, a portfolio that includes split applications and balanced use of fertilisers, precision farming, optimised crop rotations, low-protein animal feeding and the use of expensive slowrelease compounds: some of these measures have already helped to lower nitrogen losses in the EU (Oenema et al. 2009), US and Japan – but much more will have to be done in order to reconcile future needs for more nitrogen with the quest for high environmental quality.

Ecosystems and Environment 133, 280-288.

Pathak, H., Mohanty, S., Jain, N. and Bhatia, A. (2010). Nitrogen, phosphorus, and potassium in Indian agriculture.

Nutrient Cycling in Agroecosystems 86, 287-299.

Smil, V. Enriching the Earth: Fritz Haber, Carl Bosch, and the transformation of world food production. Cambridge, MA, The MIT Press, 2001. ISBN 0-262-19449-X Smil, V. Harvesting the biosphere: How much we have taken from nature.

Cambridge, MA, The MIT Press, 2011. In press.

Stoltzenberg, D. Fritz Haber: Chemist, Nobel laureate, Jew. Philadelphia, Chemical Heritage Press, 2004. ISBN 0941901-24-6 Sutton, M.A., Howard, C.M., Erisman, J.W., Billen, G., Bleeker, A.,Grennfelt, P., van Grinsven, H. and Grizzetti, B., (eds.)

The European Nitrogen Assessment: Sources, effects and policy perspectives.

Cambridge, Cambridge University Press, 2011. ISBN: 978110700612

WORLD AGRICULTURE

13

14

6/4/11

12:24

Page 1

scientific

The scale for managing production vs the scale required for ecosystem service production Tim G. Benton, AJ Dougill, EDG Fraser1 and DJB Howlett Africa College Partnership, Faculty of Biological Sciences, University of Leeds LS2 9JT, t.g.benton@leeds.ac.uk

Summary

The world is facing unprecedented long term pressures on agricultural landscapes. It will be necessary to increase food production to meet demand but this must be undertaken sustainably, with a minimum of environmental and social impacts. "Sustainable" farming is often equated with less intensive approaches such as organic farming practices that are generally more extensive than industrial farming.

Such extensive farming methods are often beneficial to the local environment but typically also have lower yields and, therefore, make the challenge of increasing global production more acute. To explore the tension between our global need to produce food and conserve nature it is useful to think of agricultural landscapes as systems that produce two axiomatic products: food (and other economic goods) and ecosystem services (which may relate to biodiversity, water, carbon storage or environmental health). Given that most empirical evidence shows that extensive farming produces lower yields and less local environmental impact than intensive systems, there are two basic land management strategies: land can be farmed extensively over a large area thereby producing less food but more ecosystem services on the same land (a "land sharing" strategy), or farmed intensively over a smaller area and the remaining land can be "saved" to be managed exclusively for ecosystem services ("land sparing").

Recent research indicates that when the extra land needed to maintain yields under extensive systems is taken into account, land sparing strategies may often be optimal in terms of balancing food production while maintaining overall ecosystem services. Furthermore, if farm management increasingly reduces intensive agriculture’s impact on the environment (say through new technologies that reduce the greenhouse gas emissions from conventional farms) the conflict between intensive and extensive systems will be additionally reduced.

Key words: Extensive and intensive agriculture, sustainable farming practices, organic farming, world food security, population growth, biodiversity and ecosystem functioning Abbreviations: GHG: Greenhouse gases

Glossary Extensive vs intensive: Intensive production systems aim to maximise the yield per unit area and typically require larger investments (in labour or capital) than extensive systems.

Extensive farms yield less agricultural produce per unit area because production methodologies are less intense. We use the terms extensive vs intensive as simple labels, whilst recognising that they are relative.

Organic farming: There is no universally accepted definition of organic agriculture but the core of organic agriculture is refraining from the use of synthetic fertilisers pesticides and genetically modified organisms. Pests and diseases are controlled with nat-

1Current

14

urally occurring means and substances according to both traditional as well as recently developed ideas.

Note that organic farming may be extensive or intensive (e.g. with high application rates of green manure, large fields etc); organic and extensive are therefore not necessarily synonyms.

Conventional farming: we use conventional farming as a label to describe common farming practice in the recent past (i.e. non-organic).

This is typically also intensive. As we develop a low carbon economy, conventional farming will necessarily become greener so that conventional intensive farming may have lower (local) environmental impacts.

Ecosystem services: Ecosystem

services are those services ecology provides that have value to humans.

They break into four main categories: provisioning (e.g. food production), regulating (e.g. water quality, pollination, pest control), supporting (e.g. soil fertility) and cultural services (e.g. providing habitat for biodiversity of cultural value).

Intensity of farming: Intensity is the amount of product per unit of input or resource. Agricultural intensity can relate to the use of space, inputs (e.g. fertiliser, water, pesticides etc.), labour or capital. There are therefore any number of ratios of intensity and an increase in one can lead to a decrease in others and the business of farming is to optimise these ratios.

address: Department of Geography, University of Guelph, Guelph, ON, N1G 2W1, Canada

WORLD AGRICULTURE

15

6/4/11

12:25

Page 1

scientific

Introduction The food security challenge The world's population is predicted to increase by 35% by 2050 (UNDP 2008). At the same time, per capita food demand is rising because as individual wealth increases, consumption, and especially the consumption of resource-intensive products such as meat and dairy, also increases.

These factors mean that the global demand for food is likely to grow at a greater rate than the population and although there are uncertainties, the most widely cited prediction comes from the FAO who calculated that 70% more food will be required by 2050 (Bruinsma 2009).

Currently, pests, diseases and post-harvest losses account for a significant waste of the global harvest. Although Parfitt et al. (2010) conclude that there is little useful data on actual postharvest losses it is possible that 15% of China’s rice harvest is lost owing to poor storage, losses in transport and inefficient processing. As a result, many suggest there is a huge scope for improving efficiency (Smil 2001). Furthermore, any behavioural change (e.g. reduced consumption of meat and dairy: see Godfray et al. 2010) will also reduce demand. Nonetheless, many argue that to meet projected demand, global food production will need to continue increasing at rates similar to those of the last two decades (Foresight 2011).

As demand is increasing, three factors limit productivity: land use change, climate change, and the need to reduce fossil fuel based inputs in farming. Land use change arises from a number of causes (Holmgren et al., 2006). For example, urbanisation is changing the relationship between society and the land, not least as rural populations decline and this reduces farmers’ access to labour, capital, and transport, thus changing agricultural practice.

In particular, many in rural Africa are asking “where is the life in farming?” and are shifting away from food production. Land is also increasingly used for non-food crops such as cotton, oil palm and biofuels. Environmental degradation such as soil erosion and salinisation has led to abandonment of agricultural land (Smith, Gregory et al. 2010). Climate change

will have major impacts on agricultural productivity and practices (Lobell, et al. 2008; Battisti and Naylor 2009; Challinor et al. 2010).

In particular, by 2050 agricultural yields in subSaharan Africa are projected to decrease by between 7 and 27%, with higher productivity areas being most affected (Schlenker and Lobell 2010). Finally, movement towards a low carbon economy, coupled with tighter environmental regulations, means that agriculture will have to reduce its use of agrochemicals, mitigate green house gas emissions, and sequester carbon in soils and biomass. This suggests that the historical growth of productivity, which is largely based on energy intensive agricultural inputs, will become more difficult to maintain.

Indeed, if low- or no-input agriculture is required, yields in many productive farming systems may drop. Thus, on the one hand demand is increasing, and on the other hand, production growth may be difficult to maintain.

Although the area of cultivated land on the planet could double (Fischer et al. 2002), meeting demand and boosting harvests cannot be met by simply taking more land into agriculture for three key reasons. First, some of the land that could be cultivated is currently tropical forest, and deforestation is a major driver of current climate change (Smith et al.

2010). Bringing such land into agriculture is counter-productive as it would increase the rate of climate change and, therefore, will require more costly mitigation, whilst simultaneously impacting on the world's most biodiverse habitat. Second, the most productive land is already cultivated so diminishing returns are likely if cultivation expands into marginal areas, as well as causing increased land degradation.

Third, non-cropped land has other uses such as for tourism, conservation of natural resources, human habitation, cultural significance, carbon storage and water quality regulation (TEEB 2010). Although these goods and services have not been fully valued economically, their importance is increasingly recognised and incorporated into environmental policies.

We are, therefore, facing a global "perfect storm" of problems in that we need to increase productivity whilst not increasing the environmental impact of farming on the land.

WORLD AGRICULTURE

15

16

6/4/11

16

12:26

Page 1

WORLD AGRICULTURE

17

6/4/11

12:26

Page 1

scientific The sustainability challenge

T

here is increasing recognition that agriculture needs to become more environmentally sustainable, in that any environmental degradation caused by agriculture should not impact on future generations' ability to utilise natural resources for their own livelihoods (WCED 1987). There are many arguments in favour of "sustainability" but an important utilitarian one is the recognition that ecosystems provide a range of goods and services, and unsustainable production implies that these would be lost. The value of the ecological services provided in agricultural landscapes is only just beginning to be recognised (Costanza et al. 1997; TEEB 2010); some services assist a farmer's yield, others provide more disbursed services of value to society in general. For example, 1520% of total crop production arises from plant species that are wholly or partially animal pollinated (Klein et al.

2007), amounting to a direct contribution of about 10% of all food production at an annual value of $153bn (Gallai et al. 2009). Similarly, "natural enemy" services provided by a range of insects and arachnids, such as small wasps, beetles and spiders, suppress pest outbreaks.A recent study indicates control of the soy bean aphid, Aphis glycines, by such natural enemies that occur in just four US states is worth $239 million per year (Landis, Gardiner et al. 2008). Elbert et al. (2009) estimate that the autotrophic micro-organisms in dryland soils absorb a petagram of carbon (1 billion metric tonnes) each year. Not only does this improve soil fertility, this amount of carbon removed from the atmosphere is valued at ca $20 billion. Thus, there are clear indications that ecology has a direct value in production systems, and may become more important in future agriculture, especially when chemical inputs and mechanisation may be restricted by carbon costs.

Extensive vs intensive: which is more sustainable?

Our aim in this paper is to examine the relative costs and benefits of extensive vs intensive farming in meeting both the food security and sustainability challenges. We highlight the issue that if farming is more extensive it requires more land to have the same output of produce, which itself carries 2

an environmental cost that needs to be considered; and that in some circumstances "intensive farming" may be more sustainable when judged from a broad perspective. The discussion takes a holistic view of how the goods and services required by society can be optimised in agricultural landscapes, rather than contrasting farm management strategies from a farmer's perspective. Furthermore, we briefly discuss the relative carbon costs per unit output of organic vs intensive agriculture and that organic farming may be similar in carbon efficiency to conventional agriculture. We conclude that further greening of "conventional" agriculture, coupled with appropriate management of spared lands, may allow high production areas to maintain high production in a sustainable way, whilst other areas may be naturally suited to extensive farming. We hope, therefore, that this paper contributes to a mounting body of evidence that there is less need for a polarisation of views towards extensive (sustainable) and intensive (unsustainable).

The landscape view of agriculture: Sparing vs sharing

There is a considerable debate in the literature as to the extent to which different farming systems have the potential to produce adequate nutrition for the global population (for example see: Connor, 2008; Badgley and Perfecto 2007). There are many studies that cite specific cases of highly productive organic farms and argue that organic methods have the potential to “feed the world” (Coleman 1995; Badgley et al. 2007). Similarly, there are others who identify conventional farms that are high in biodiversity, and low in other environmental impacts, to demonstrate that conventional farms need not be bad for the environment (e.g. Linking Environment and Farming 2011).

Nevertheless, most of the scientific literature points out that minimising the local environmental impacts of farming is favoured by extensive farming, of which organic farming is typically seen as an exemplar. Extensive farms are usually less productive in terms of yield but have more biodiversity than conventional farms. So, when we stand aside from specific examples, there is a general consensus in the literature that if farmers traded off yield to minimise local environmental impacts (such as by adopting the organic methods that certain groups of consumers demand), then, at a global scale, agriculture would expand its land base to maintain production.

This exposes a very serious tension

since it seems that, given the most commonly used conventional and organic practices, our need for more food competes directly with our need to conserve land for biodiversity and ecosystem services2. One way of resolving this tension lies in not thinking of a farmer’s field in isolation, but thinking of a field within a landscape.

Ecosystems, and the service they provide in an agricultural region, reflect not only the organisms present in the cultivated fields but also those in the landscape around the agricultural land (Weibull et al. 2003; Gabriel et al. 2006; Carre et al. 2009; Batary et al. 2010; Chamberlain et al.

2010; Diekotter et al. 2010).

Therefore, management of ecosystem services (which may be achieved through national level policy that establishes incentives that reward farmers who use farm management that sequesters carbon, provide habitat, etc.) requires consideration of the field, farm and landscape together.

This view implies that while a field may be specialised for production, a landscape can be multifunctional as it produces both agricultural produce and biodiversity. Society demands both products and so the conceptual question becomes "what is the optimal way to deliver both products from the same landscape?"

Situating farm ecology within the larger landscape is highlighted in a landmark paper (Green et al. 2005) where the authors contrasted alternative hypothetical strategies when a set level of food was required from a single landscape. The first hypothetical landuse strategy was where the whole area was farmed extensively, in a way that yielded less food but consequently gained more biodiversity (so called "land sharing").

The contrasting option was where some of the land was farmed intensively to produce the required yield, thus allowing “spare land” to be managed for biodiversity ("land sparing"). Green et al.’s paper analysed “optimal land management” as a function of the costs and benefits to both yield and biodiversity.

While dividing land management strategies into these two broad categories is useful from a heuristic perspective, it is important to acknowledge that in the real world, most landscapes should be seen as falling along a continuum that ranges

The following argument broadly applies for a range of ecological currencies, so we shall use “biodiversity” as a generic term for ecosystem service or ecology

WORLD AGRICULTURE

17

18

6/4/11

12:27

Page 1

scientific from those that intensively produce food (thus representing the landsparing approach) to those more extensively managed that would represent the land-sharing strategy. It is also important to note that most farmers do not explicitly adopt land sparinas management strategies, but rather choose those management methods they believe will provide an economic livelihood. It is typically only at an aggregate level that we can then categorise the resulting land use patterns as representing land sparing or sharing strategies. With these two caveats aside, the arguments about the merits of land sparing and sharing have been empirically explored in a recent study that compared organic and non-organic farms in the UK (Gabriel et al. 2009; Gabriel et al.

2010; Hodgson et al. 2010). On a very well controlled, like-for-like comparison, organic farms were better for biodiversity (though the effect varied across different plant and animal groups) with biodiversity increasing by about 12% on average (Gabriel et al. 2010). But also in a like-for-like comparison of the field yields, yields of organic winter cereals in each field were only about 45% of the conventional paired field. For butterflies, for which biodiversity was ~40% higher on organic farms, this study also assessed biodiversity on spared land in local nature reserves.

The butterfly biodiversity data were then used to model the optimal landscape configuration to maintain food production while maximising biodiversity. This approach indicated that if organic yields were greater than 87% of the conventional yields, organic farming produced more biodiversity whilst retaining food yields across the landscape (Hodgson et al.

2010). Alternatively, when organic yields were below this threshold, biodiversity and food production were maximised by farming intensively to maximise production in some places while allowing land elsewhere to be spared for biodiversity. As the observed yields in the collected data were below this critical threshold, the conclusion of this study is that in the lowlands of the UK, a land sparing strategy is optimal for both food production and biodiversity conservation.

3

But this result is highly context dependent. The conclusion that land sparing is optimal in a productive landscape does not mean that everywhere else should embrace intensive farming practices as the best way of producing both food and biodiversity. For instance, studies on the production of the biofuel crop Jatropha curcas in Africa and India highlight that small-scale and community-led developments are able to produce reasonable yields, make a meaningful contribution to local livelihoods and can help to protect ecosystem services, including biodiversity. In particular, where such small scale projects have been introduced, scholars have observed that in addition to boosting farm income, such projects may help farmers retain landscape heterogeneity better than large scale bio-energy operations (see Achten et al. 2010).

This result is confirmed by studies from rural Malawi which demonstrate that a range of ecological problems (from pests and diseases: ecosystem disservices) make large scale plantations less attractive than small scale projects (Dyer et al., submitted).

Together these studies suggest that in schemes for J. curcas production in Africa a local-scale land sharing strategy is the best option.

Our conclusion is that whether land sparing or land sharing is optimal depends crucially on the place. For instance, regions with small fields, steep valleys, or large amounts of noncropped habitat impose constraints on intensive production. In such regions, yields will be lower but biodiversity may be higher owing to the greater habitat heterogeneity (Benton et al.

2003). In such regions, land sharing strategies will likely be optimal.

Conversely, a flat landscape with fertile soil may naturally be low in biodiversity and so the optimal management would be to farm more intensively to spare land elsewhere for biodiversity conservation.

Inputs and outputs: the carbon costs of farming When there is a need to produce a given amount of food, the argument

above suggests that in many productive landscapes, conventional farming (because it minimises the land area required) may be more sustainable than extensive or organic farming at producing both food and ecosystem services. However, a further argument for extensive systems being locally more sustainable is that they are "environmentally friendly" due to their lower inputs3. This need not always be the case. A recent study developed a full carbon-account for 17 years of a corn-soybean rotation system in Michigan (Gelfand et al. 2010). This showed that the efficiency (the outputs per unit input) were almost identical for organic and conventional approaches. Although organic methods "saved" energy costs by not using synthetic chemicals, they "spent more" on the greater mechanised costs of farming (for example requiring more passes with machinery during weed control and a winter cover crop of clover). So, although, extensive farming in the guise of organic production may have environmental benefits in locally raising biodiversity, it does not necessarily reduce the carbon cost of farming (per unit of production) and it also requires more land to produce the same outputs.

The Gelfand study also explored the relative efficiencies of two further management systems: "no till" (i.e. without deep ploughing, but maintaining chemical inputs) and "low input" (i.e. where there is low chemical input coupled with mechanised weed control).

These “alternative management� strategies demonstrated greater production efficiencies than either conventional or organic, and the no-till system also had a greater average yield than the conventional system.

No-till systems maintain soil carbon stocks (West and Post 2002) and require less energy, owing to a reduction in the fuel costs of mechanisation.

Whilst these alternative systems may not be universally appropriate, they illustrate that more sustainable conventional farming practices are possible. Thus, rather than creating a misleading contrast by dividing farming systems into either organic/extensive and conventional/intensive there needs to be greater recognition that future farming has the potential to maintain yield whilst becoming "greener" by further optimising inputs and practices to reduce environmental impacts. We return to this issue below.

Extensive farming, with lower or zero inputs of synthetic products, does not necessarily equate to a lower environmental impact. Green fertiliser, if over-applied, can lead to eutrophication of water courses; and permitted organic chemical uses include some high-impact toxic chemicals such as copper and natural pyrethroids for pest control. Furthermore, organic methods of weed control may require greater fuel use, contributing to GHG emission.

18

WORLD AGRICULTURE

19

6/4/11

12:33

Page 1

scientific The spatial scale of sparing vs sharing

The key point of the land sparing vs land sharing argument is that the costs and benefits of different land management strategies must be assessed across all affected land. If a fixed level of production is required in a particular area (farm, landscape or region) converting to extensive farming implies that farming elsewhere will need to intensify (e.g. by converting extensive into intensive, or converting semi-natural land to farmland) and so the net landscape-scale effect needs consideration. The best solution is place-dependent (as discussed above) and scale independent. For example, if within a country costs and benefits vary regionally, higher productivity in one region will go to make a larger contribution towards meeting production needs, thus allowing other regions to be relatively spared. Hence, one can imagine hierarchical applications of this argument: comparing landscapes within a region, land sparing in some, land sharing in others; comparing regions, with greater proportions of intensive production plus spared land in the higher production regions, and more sharing in the lower production regions and so on4. Of course, it is important to acknowledge that farmers do not manage at the landscape scale but an awareness of these tradeoffs at larger spatial scales is important for the policy makers who establish the rules and incentives by which farmers are bound.

To extend this argument, consider the case for organic farming within the EU. Organic farms tend to support local ecology as their farming practices promote landscape heterogeneity (through a diversity of crops and rotations), in addition to the reduction in synthetic applications of fertilisers and pesticides. This extensification usually leads to lower yields. All things being equal, if consumers demanded more local organic products, and farmers in Europe responded by expanding the number of hectares farmed using organic methods, we might expect a reduction in gross European food production, and this could result in more food imports from regions such as Asia and sub-Saharan Africa. Under such a scenario, we might expect an increase in intensification or more land being brought into production in

these regions to meet both their growing home markets (where demand is growing faster than in EU) and to supply extra EU demand. This carries both environmental and economic implications. Adding further complexity, the EU has much tighter environmental regulations relative to other regions, so greater intensification elsewhere may result in greater environmental damage than in Europe. Finally, since biodiversity is typically richer in warmer parts of the world, the environmental damage caused by an expansion of organic farming in Europe, may add additional stress to vulnerable and ecologically valuable parts of the world. It has recently been estimated that European imports of food already account for a virtual land grab of the equivalent area of Germany (34 m ha) (von Witzke, 2010; von Witzke & Noleppa 2010).

If Europe increased the proportion of its land devoted to organic farming to 20%, then it is likely that >10 m ha, an area equivalent to the size of Portugal, would need to be devoted to export crops from the developing world to Europe (von Witzke 2010; von Witzke & Noleppa 2010). Hence, organic farming in Europe may help conserve European environments, but only through the potential export (and magnification) of the environmental costs to elsewhere in the globe.

Finally, it is important to acknowledge the argument that exports from Latin America, Africa and SE Asia to the developed world provide much needed hard currency for poverty ridden economies and this helps maintain food security for millions of people in these regions.

Nevertheless, one of the arguments from this paper is that where rich

nations under-produce many crops and, as a consequence import more produce from poor nations, then ecosystem services in these environmentally fragile and important regions may be undermined. For example, the UK government’s Foresight Report addresses this and argues that long-term global food security can only be met if productive areas continue to be our main centres of production (Foresight 2011). Does this mean the arguments presented here could be used to justify protecting our own farmers, thereby cutting the developing world off from access to western markets? To resolve this tension, policy makers in the EU need to consider a portfolio of policies thatreward farmers who use green-yetintensive farming practices in regions that are naturally productive; but different policies need to be enacted that reward farmers in other regions (and especially those in the Global South) for maintaining ecosystem services and farming using more land sharing methods to serve the needs of local markets.

The future

A world where extensive farming dominates is possible to imagine, in that extensive agricultural systems can potentially provide sufficient energy to maintain a healthy life for the growing population. However, this future would require such considerable change in individual and societal behaviour (e.g. the widespread adoption of vegetarian diets) that, in our opinion, this is unlikely to happen in the short term. Our pessimism is born out of our observation about how society has responded to climate change: despite the threat of, and evidence for, climate change, behavioural change to date has been relatively small. It is also not clear that an

4 There are clearly a number of policy levers that can be used to encourage the "optimally designed" landscape; for example, agri-environmental subsidies, planning regulations or even local taxation; the key concept is for any such schemes to be responsive to the needs of different places.

WORLD AGRICULTURE

19

20

6/4/11

12:34

Page 1

scientific ‘To balance competing needs for both food production and nature conservation, landscapes need to be actively managed for both outputs. In the land sharing scenarios, much of the biodiversity will exist in the background landscape’ “organic world” is actually the most sustainable solution. Moving to organic production may intensify pressure on landscapes and this could lead to greater deforestation, greater release of carbon into the atmospheres and greater long term climatic effects.

Despite our pessimism about the likelihood of shifting behaviour, we take from our analysis that farming has unnecessarily been polarised into an intensive vs. extensive debate (in any of the many variants of this discussion). High output systems are by definition intensive, but this need not equate to “industrial farming” or “high environmental cost” farming.

Greening of “conventional” agriculture is already underway, partly driven by consumer demand, agri-environment schemes, tighter environmental regulation and recognition of the rising cost of oil driving up input costs.

Furthermore, research demonstrates that practices such as no-till and lowinput agriculture can maintain production, increase efficiency and have lower environmental impacts than "conventional" farming (and perhaps also lower environmental impacts than organic farming, if one accounts for the extra land needed for organic production). Increasingly, both policy makers and producers are valuing the ecosystem services that contribute to yields and, therefore, ensuring operations have minimal impact on local biodiversity. Hence, we believe that the weight of the evidence suggests that ecological, or green, agriculture can exist without wholesale adoption of extensive or other organic practice.

In the developed world, greener intensive agriculture may manifest itself in an increase in no-till, low-input and other agronomic systems. Plus the further development of precision agriculture, using remote-sensed data producing high-resolution maps of fields to target inputs, can also radically improve efficiency and reduce inputs (Bongiovanni and Lowenberg-Deboer 2004). Clearly, plant-breeding technologies (including molecular techniques such as gene tilling, for creating and identifying new variants, and also genetically modified crops) are potential partial solutions for maintaining, or increasing, yield in a "greener"

20

WORLD AGRICULTURE

way. These variants may also require fewer inputs (in terms of fertiliser or water, by changing root architecture or by modifying resistance to pests).

may be home to considerably more wildlife friendly land than has been true of conventional farming landscapes in the last few decades.

In the developing world, a form of organic farming often represents good farming practice, in that considerable management is necessary to avoid loss of yield to pests and diseases.

However, there is widespread acknowledgement that some synthetic inputs can radically improve yields (Vitousek et al. 2009), which can both reduce poverty and enhance food security.

Relative to strictly followed organic practices, such low-input systems can create radical increases in yield and can be managed in a relatively sustainable way.

Conclusions

To balance competing needs for both food production and nature conservation, landscapes need to be actively managed for both outputs. In the land sharing scenarios, much of the biodiversity will exist in the background landscape. In land sparing scenarios, the spared land needs to be actively managed for biodiversity (and not simply left fallow). In the discussions above, we have not addressed how the spared land could be laid out.

Given that agricultural land may increasingly require ecosystem services for which non-cropped areas may be prime sources (e.g. spared land may provide habitat for predator insect or bird species that reduce pest damage in cropped areas), then we must not think of spared land solely as being in blocks or “nature reserves”. Rather, an optimal arrangement might be where spared land becomes a network of patches across the landscape linked by suitable corridors. So, even highly productive landscapes may have high biodiversity provided across the landscape. The management of this spared land may evolve from the considerable current research on the efficacy of agri-environment schemes linked with input by the land managers in specific localities. High production, land sparing landscapes, need not be the "green desert of industrialised farming" that people often imagine. Owing to the greening of conventional farming and proper management of spared land, these areas

Extensification will not be the answer to global issues of food security owing to the two major barriers of having insufficient land to expand into, and the need for considerable change in dietary habits. A recent study (Smith et al. 2010 p2955) concludes: "Given the need to feed 9 billion people by the middle of this century, and increasing competition for land to deliver non-food ecosystem services, it is clear that agricultural productivity needs to be maintained where it is already close to optimal, or increased in the large proportion of the world where it is suboptimal".

Local extensification only becomes possible if somewhere else intensifies, and it becomes a matter of assessing the costs and benefits of regional, country and local strategies to minimise environmental impact, whilst maintaining the necessary food production. In naturally productive areas, it is likely that land sparing strategies give the optimal mix of ecology and food; whereas in naturally less productive areas, land sharing becomes optimal. This argument applies to a degree at a range of spatial scales.

Extensification is "not the answer", but suggestions for the answer can be found in the greening of existing methodologies to reduce climate impacts and synthetic inputs. This should be coupled with management specific to the local landscape and local users, consistent with appreciating that agricultural landscapes produce more than just agricultural produce. This landscape view contributes to a reconciliation of “conservation” and “production”, because recognising that landscapes produce two (or more) outputs allows a conceptual optimisation of the landscape-design to produce the most of both.

Sometimes, the optimal landscape design will appear to be a traditional extensive landscape, other times it will

21

6/4/11

12:36

Page 1

scientific look more like an intensively farmed landscape but with specific areas of land managed very actively to maximise ecosystem service production, biodiversity or conservation. This spared and managed land will most likely be required as a network crossing the agricultural landscape, allowing the provision of ecosystem services (the distance that many natural predators move into cropped land from non-cropped land is a few hundred metres). A greening of conventional agriculture that couples agronomy,

References BAchten, W.M.J., Maes, W.H., Aerts, R., Verchot, L., Trabucco, A., Mathijs, E., Singh, V.P. & Muys, B., 2010. Jatropha: From global hype to local opportunity.

Journal of Arid Environments. 74, 164-165.

Badgley, C., J. Moghtader, et al.

(2007). "Organic agriculture and the global food supply." Renewable Agriculture and Food Systems 22(02): 86108.

Badgley, C. and I. Perfecto (2007).

"Can organic agriculture feed the world?" Renewable Agriculture and Food Systems 22(02): 80-86.

Batary, P., T. Matthiesen, et al. (2010).

Landscape-moderated importance of hedges in conserving farmland bird diversity of organic vs. conventional croplands and grasslands. Biological Conservation 143(9): 2020-2027.

Battisti, D. S. and R. L. Naylor (2009).

Historical Warnings of Future Food Insecurity with Unprecedented Seasonal Heat. Science 323(5911): 240-244.

Benton, T. G., J. A. Vickery, et al.

(2003). Farmland biodiversity: is habitat heterogeneity the key? Trends in Ecology & Evolution 18(4): 182-188.

Bongiovanni, R. and J. LowenbergDeboer (2004). Precision Agriculture and Sustainability. Precision Agriculture 5(4): 359-387.

Bruinsma, J. (2009). The resource outlook to 2050: by how much do land, water and crop yields need to increase by 2050? Expert Meeting on How to Feed the World in 2050. Rome, FAO. Carre, G., P. Roche, et al. (2009).

Landscape context and habitat type as drivers of bee diversity in European annual crops. Agriculture Ecosystems & Environment 133(1-2): 40-47.

Challinor, A. Simelton, E., Fraser, E.D.G., Hemming, D., Collins, M. (2010) Increased crop failure due to climate change: assessing adaptation options using models and socio-economic data for wheat in China. Environmental Research Letters. 5(3) (1-8).

Chamberlain, D. E., A. Joys, et al.

(2010). Does organic farming benefit farmland birds in winter? Biology Letters 6(1): 82-84.

Coleman, E. (1995). The New Organic Grower. Totnes, England, Chelsea Green.

Connor, D. (2008). Organic Agriculture Cannot Feed the World. Field Crops Research 106: 187-190.

Costanza, R., R. d'Arge, et al. (1997).

The value of the world's ecosystem services and natural capital. Nature 387(6630): 253-260.

Diekotter, T., S. Wamser, et al. (2010).

Landscape and management effects on structure and function of soil arthropod communities in winter wheat. Agriculture Ecosystems & Environment 137(1-2): 108112.

Dyer, J.C., Stringer, L.C. and Dougill, A.J. (submitted). Jatropha curcas: Sowing

information technology and remote sensing is required. This will allow low-input, low-environmental impact farming to push productivity in areas where conditions are suitable, linked with spared land managed to provide biodiversity. The goal (from a policy perspective) is to create incentives that result in a farming system that, at a landscape scale, is as good (or better) for biodiversity and ecosystem services than if the whole area was farmed organically. It is perfectly possible for there not to be a societal choice local seeds of success in Malawi.

Submitted to Journal of Arid Environments.

Elbert, W., Weber, B., Büdel, B., Andreae, M.O. and Pöschl, U. 2009.

‘Microbiotic crusts on soil, rock and plants: neglected major players in the global cycles of carbon and nitrogen’.

Biogeosciences 6:6983-7015 Fischer, G., van Velthuizen, H., Shah, M. & Nachtergaele, F. 2002. Global Agroecological Assessment for Agriculture in the 21st Century: Methodology and results.

Laxenburg: IIASA. Foresight (2011). Foresight. The Future of Food and Farming, Final Project Report.

The Government Office for Science, London. http://www.bis.gov.uk/Foresight Gabriel, D., S. J. Carver, et al. (2009).

The spatial aggregation of organic farming in England and its underlying environmental correlates. Journal of Applied Ecology 46(2): 323-333.

Gabriel, D., I. Roschewitz, et al.

(2006). Beta diversity at different spatial scales: Plant communities in organic and conventional agriculture. Ecological Applications 16(5): 2011-2021.

Gabriel, D., S. M. Sait, et al. (2010).

Scale matters: the impact of organic farming on biodiversity at different spatial scales. Ecology Letters 13(7): 858869.

Gallai, N., J. M. Salles, et al. (2009).

Economic valuation of the vulnerability of world agriculture confronted with pollinator decline. Ecological Economics 68(3): 810-821.

Gelfand, I., S. S. Snapp, et al. (2010).

Energy Efficiency of Conventional, Organic, and Alternative Cropping Systems for Food and Fuel at a Site in the US Midwest. Environmental Science & Technology 44(10): 4006-4011.

Godfray, H. C. J., J. R. Beddington, et al. (2010). "Food Security: The Challenge of Feeding 9 Billion People." Science 327(5967): 812-818.

Green, R. E., S. J. Cornell, et al. (2005).

"Farming and the fate of wild nature."

Science 307(5709): 550-555.

Hodgson, J. A., W. E. Kunin, et al.

(2010). "Comparing organic farming and land sparing: optimizing yield and butterfly populations at a landscape scale." Ecology Letters 13(11): 1358-1367.

Holmgren, P. 2006. Global land use area change matrix. Forest Resources Assessment Working Paper 134. Rome: FAO Klein, A. M., B. E. Vaissiere, et al.

(2007). "Importance of pollinators in changing landscapes for world crops."

Proceedings of the Royal Society BBiological Sciences 274(1608): 303-313.

Landis, D. A., M. M. Gardiner, et al.

(2008). "Increasing corn for biofuel production reduces biocontrol services in agricultural landscapes." Proceedings of the National Academy of Sciences of the United States of America 105(51): 2055220557.

between producing sufficient food with high environmental impact OR producing insufficient food in a sustainable way, but BOTH to produce enough food and to do it sustainably.

The landscape view of farming is a tool towards aligning the traditionally opposing camps, and moving towards more sustainable agriculture that helps provide food security for an expanding population, the livelihoods of hundreds of millions of people and a way out of poverty for many in the developing world.

Linking Environment and Farming.

(2011). "Organization's Web page."

Retrieved Feb. 11, 2011, from http://www.leafuk.org/.

Lobell, D. B., M. B. Burke, et al. (2008).

"Prioritizing climate change adaptation needs for food security in 2030." Science 319(5863): 607-610.

Parfitt, J., M. Barthel, et al. (2010).

"Food waste within food supply chains: quantification and potential for change to 2050." Philosophical Transactions of the Royal Society B: Biological Sciences 365(1554): 3065-3081.

Schlenker, W. and D. B. Lobell (2010).

"Robust negative impacts of climate change on African agriculture."

Environmental Research Letters 5(1).

Smith, P., P. J. Gregory, et al. (2010).

"Competition for land." Philosophical Transactions of the Royal Society BBiological Sciences 365(1554): 2941-2957.

Smil, V., 2001: Feeding the World.

Cambridge, MA: MIT Press.

TEEB (2010) The Economics of Ecosystems and Biodiversity: Mainstreaming the Economics of Nature: A synthesis of the approach, conclusions and recommendations of TEEB. UNEP ISBN 9783-9813410-3-4 Vitousek, P. M., R. Naylor, et al.

(2009). "Nutrient Imbalances in Agricultural Development." Science 324(5934): 1519-1520.

Weibull, A. C., O. Ostman, et al.

(2003). "Species richness in agroecosystems: the effect of landscape, habitat and farm management."

Biodiversity and Conservation 12(7): 13351355.

WCED, 1987 World Commission on Environment and Development, WCED, 1987, Our Common Future, United Nations.

West, T. O. and W. M. Post (2002).

"Soil organic carbon sequestration rates by tillage and crop rotation: A global data analysis." Soil Science Society of America Journal 66(6): 1930-1946.

Vitousek, P. M., R. Naylor, et al.

(2009). Nutrient Imbalances in Agricultural Development. Science 324(5934): 1519-1520. von Witzke, H. (2010), Towards the Third Green Revolution: World Agriculture a Key Industry of the 21st Century.

Augsburg von Witzke, H. and S. Noleppa (2010), EU agricultural production and trade: Can more efficiency prevent increasing land-grabbing outside of Europe?

Research Report, University of Piacenca (http://www.appgagscience.org.uk/link edfiles/Final_Report_Opera.pdf)

WORLD AGRICULTURE

21

22

6/4/11

12:37

Page 1

scientific

Pesticide toxicity and public chemophobia: how toxic are modern-day pesticides?

David Hughes

Syngenta Jealott’s Hill International Research Centre, Bracknell, Berkshire RG42 6EY UK

Summary Global food security is a major issue for the future of humanity. Food demand is predicted to grow strongly for at least the next 40 years and food supply is already struggling to keep up. Protecting crops from weeds, fungal diseases and herbivorous pests is a critical part of global agriculture and synthetic pesticides are the most effective tools farmers currently have to achieve this. Nevertheless the public perception of pesticides is strongly negative. In particular pesticides are perceived to be highly toxic and it is widely believed that there are significant negative health implications for people eating food containing synthetic pesticide residues. This paper shows that modern day pesticides are not particularly toxic relative to other commonly encountered chemicals, both synthetic and natural. The levels of pesticide residue found in food are many orders of magnitude too low to have any health implications for consumers. In fact the use of pesticides contributes significantly to food safety due to the reduction of mycotoxin contamination. Consuming food was much more dangerous in the days before pesticides.

Key words: Pesticide toxicity; public perceptions; food security

Glossary Rat acute oral LD50: the ingested dose of chemical required to kill half the members of a tested population of rats after a specified time.

Acute reference dose: the maximum dose of a chemical taken over a short time period (e.g. a single dose, or over a single day) which appears

to be without appreciable risk to the consumer.

Maximum Residue Level (MRL): the maximum concentration of a pesticide that is legally permitted in or on a food commodity.

Acceptable Daily Intake (ADI): the maximum daily dosage of a chemical which, during an entire life-

Introduction Humanity is facing a number of profound and unprecedented challenges. How are we going to satisfy our seemingly insatiable appetite for energy? How are we going to supply enough fresh water to the places that need it? How can we prevent any further catastrophic collapse in global biodiversity? What impact will climate change have and how can we adapt and mitigate against the worst of its effects?

These challenges are all intimately interlinked and they are all linked to perhaps the most immediate and profound challenge we face: how can we produce enough food to satisfy the nutritional needs of the growing world population over the next 50 years?

22

WORLD AGRICULTURE

time of exposure, appears to be without appreciable risk to the consumer.

No Observed Adverse Effect Level (NOAEL): the highest dose of a chemical that resulted in no observable adverse effects on test animals over the complete duration of a controlled study.

Food demand is growing strongly. The world population is rising fast, from 6.8 billion people today to an estimated nine billion people by 2050 (see Fig. 1, plotted from data obtained from the FAO, 2011).

Also increasing levels of personal wealth are driving demand for more sophisticated diets, particularly meat and dairy products, which are relatively inefficient in energy terms to produce. It is estimated that primary global food demand will increase by between 50-100% between now and 2050 (Royal Society, 2009; Godfrey et al., 2010). Others have calculated that more food will need to be produced in the next 50 years than has been produced in the previous 10 000 years combined in order to satisfy demand (One World, 2011).

23

6/4/11

12:38

Page 1

scientific the Americas (Pivonia and Yang 2006) and a strain of wheat stem rust (Ug-99) in Africa and the Middle East (Zhang et al. 2010).

Superimposed on these biological challenges is the effect of increasingly stringent pesticide legislation. The imposition of tough, arbitrary, hazard-based stanFig. 1: Historical and projected human population (Source: FAO) dards for pesticide safety in Europe is Global food supply on the having the effect of removing safe and effective pest control strategies from other hand is struggling European farmers, compromising their ability to compete in the global food to keep up with demand production market. A recent report on and is facing a number the impact of these proposals on UK agriculture (ADAS 2008) estimated of pressures: that wheat production would decrease by 26-62% (depending on the exact scenario implemented), potato prohere is no realistic possibility of duction would decrease by 22-53% simply increasing global farmed and brassica production would area to keep up with food decrease by 25-77%. Also the potendemand. Indeed we may be fortunate tially dramatic reduction in the numeven to retain the area of farmland ber and diversity of pesticides available currently available in the long term. will make it much more difficult for Almost the entire future rise in global farmers to manage the evolution of pesticide resistance which generally population is predicted to be in urban relies upon rotating through a range areas (Fig. 1) and hence cities will of diverse pest control strategies. have to expand to cope, potentially eating up surrounding farmland. The A number of farm input streams are fertility of some areas of farmland is coming under increasing pressure. being degraded by poor farming Synthetic nitrogen fertilisers take sigpractices leading to erosion, salination nificant amounts of energy to produce or compaction of the soil, or chronic and hence their price tends to track depletion of nutrients (Tilman et al. the oil price which is rising strongly 2002; Foresight 2011). In the future (Foresight 2011). Economically extractable supplies of mineral phosthere may be an increase in the arable phates are declining and are largely area used for non-food crops such as concentrated in North Africa. The conbiofuels or the “biorefining” of other tinuity of phosphorus supply is a matfeedstocks (Foresight, 2011). It is also ter of some controversy, but some estigenerally recognised that the large mates suggest that “peak phosphorus” scale conversion of wild lands to supply could be reached by around farmland would have further 2030 (Cordell et al. 2009). Water supcatastrophic effects on biodiversity, ply is the limiting factor for agriculturand greenhouse gas emissions al yields in many parts of the world. It associated with land-use change. is estimated that 70% of the world’s fresh water is used in agriculture and yet it seems that water is becoming Pests that attack arable crops in the increasingly scarce in the areas that field are becoming more difficult to need it most. Already 25% of the control. Resistance is developing to world’s rivers do not reliably reach the many pesticides, reducing their effecsea since at times every drop of water tiveness or in some cases making them is being extracted for industrial, agricompletely obsolete (Denholm et al. cultural and domestic uses, and we are 2002; Merotto Jr. et al. 2009). This is mining ancient “fossil” groundwater at simply a consequence of Darwinian an unsustainable rate (Ridoutt and evolution under high selection presPfister 2010). sure, exactly analogous to the evolution of antibiotic resistance in bacteria.

The global credit crisis has hit farmOccasionally new pest species emerge ing hard. Farmers rely on credit to as significant threats to agriculture. invest in the inputs required to grow Two recent examples of new problemtheir crops. Less available credit means atic fungal diseases are soybean rust in

T

that farmers are less able to invest in more expensive but higher performing seed varieties and crop protection strategies resulting in lower achievable yields (Sanchez 2005). Similarly farmers in some parts of the developing world find it difficult to insure their crops, making them less likely to invest the money required to purchase premium inputs if the resulting crops may be at risk of damage by uncontrollable circumstances, such as extreme weather events (Thomas 2008).

Lack of infrastructure is limiting agricultural productivity in some parts of the world. Poor roads, a lack of proper food storage facilities and suitable vehicles (especially with refrigeration facilities) means that many farmers in the developing world cannot gain fair access to global food markets and huge amounts of food are being wasted. Also a lack of adequate communication technology infrastructure (mobile phones, internet access) can hinder farmers when they are deciding what crops to grow and |how best to grow them (Sanchez 2005).

All of these pressures are underpinned by the uncertainties associated with climate change. Increasing temperatures accelerate plant maturation and inhibit leaf development and grain filling. This, in combination with a lack of water, can have a devastating effect on crop yields. In the anomalously hot summer in Europe in 2003 yields of wheat fell by over 20% and yields of maize fell by 30%. Models predict that by the end of the 21st century, the average summer in Europe will be hotter than the summer of 2003 (Battisti and Naylor 2009). As the climate changes, the zones in which crops can be grown will shift.

Some currently fertile regions are likely to become too hot and dry to support any agriculture at all but on the other hand, some regions which are currently too cold to farm may become fertile. An International Food Policy Research Institute report (Nelson et al.

2009) attempted to quantify the effect of both yield changes and farmed area on food production as a result of climate change. This report concludes that for the two crops most critical for human consumption, global rice production would fall by 10-15% and global wheat production would fall by 20-30%.

The issue of how we can feed the world’s population over the next 50 to 100 years without utterly devastating the global environment in the process is the most significant challenge humanity faces. It is unlikely that a single “silver bullet” technology will be

WORLD AGRICULTURE

23

24

6/4/11

12:39

Page 1

scientific ‘Despite these benefits the general public has a strong negative perception about the use of pesticides and especially their impact on the health of people who consume food containing pesticide residues. developed that will provide a complete solution to our needs. Rather, if we are to succeed it will be through the judicious use of all the technological tools in the agricultural tool box, alongside traditional knowledge and techniques. These tools should be thoughtfully and appropriately applied in order to optimise the efficiency of agriculture in every individual local situation. All of our tools have a part to play, it is unfortunate therefore that public opinion is so set against one of the most important and useful tools at our disposal.

The benefits of pesticides

There is universal agreement that farmers must take measures to protect their crops from pests. Weeds compete with crop plants for soil nutrients, water and sunlight. Plant infectious diseases are usually caused by fungi (or similar organisms), but bacterial and viral diseases are also damaging.

Invertebrate pests feed on the crop, directly impacting on yield and quality, but some can also act as vectors which spread disease. There are numerous pest control strategies used by farmers worldwide. Agronomic practices are important, for instance crop rotation can suppress plant diseases and invertebrate pests, whilst ploughing and hand weeding can be used to manage invasive weeds. Biological methods can be used to control insects, for example bacteria which produce insecticidal toxins like Bacillus thuringiensis, entomopathogenic fungi that infect insects, and predatory species such as wasps and ladybirds that attack caterpillars and aphids respectively. Also the breeding of plants to have intrinsic resistance to fungal and invertebrate pests is critically important. This was traditionally achieved by the tortuous process of random crossing and selection with generally no idea how increased resistance was being achieved. More recently plants have been genetically engineered to resist pests using more rational and targeted strategies.

However, by far the most significant method for controlling pests on arable crops is the use of chemical pesticides (more accurately – crop protection chemicals). Pesticides are often used in combination with one or more of the

24 WORLD AGRICULTURE

other pest control methods described above but the use of pesticides is usually at the heart of a farmer’s pest control strategy. To understand why, it is necessary to consider the main benefits the use of pesticides can bring: The key benefit is increased yield.

Pesticides remain the dominant and most effective mechanism to control pests, and it has been estimated that the use of crop protection technologies increases global crop yields by 92% (calculated from Oerke et al.

1994). Without crop protection the world would be able to produce little more than half of the food currently produced. More specifically crop protection increases global yields of wheat and rice by 43% and 172% respectively (calculated from Oerke 2006).

Pesticide use can also improve the quality of the harvested crop, ensuring that the food we eat is not damaged by insects or blemished by disease whilst in the field or after harvest.

Pesticide use can improve the safety of our food through the suppression of pests and diseases which can contaminate crops with natural toxins (see below).

The use of pesticides has a direct beneficial effect on global biodiversity by helping humanity to produce the food it needs without having to convert large areas of pristine wild land to farmland. A number of studies have examined how best to maximise biodiversity whilst producing a given amount of food from a given amount of land. This raises the question: is it better to farm the whole area “ecologically”, or is it better to farm a proportion of the area “intensively” and allow the remainder to revert to wild land?

The answer is clear: wild land is typically much more biodiverse than any farmland, and the differences in biodiversity between ecological farmland and intensive farmland are generally smaller than the differences in crop yield. This means that it is usually better to farm the existing land intensively rather than convert wild land to farmland (Green et al. 2005; Hodgson et al. 2010; Benton et al. this issue).

Use of pesticides provides economic and social benefits as they help to

keep food prices relatively low. It has been estimated that without pesticides food prices in the UK would rise by about 40%, lowering family disposable income with knock-on effects on the quality of family life. It is also likely that rates of consumption of fresh fruit and vegetables would decrease resulting in a detrimental impact on public health (Rickard 2010).

In 1994 it was estimated that the amount of additional food produced owing to crop protection was worth $160 billion (Oerke et al. 1994). The global crop protection market that year was worth around $28 billion, so on average for every dollar invested on crop protection, the farmer recouped over $5.50 in increased yield and quality, an impressive rate of return.

Despite these benefits the general public has a strong negative perception about the use of pesticides and especially their impact on the health of people who consume food containing pesticide residues. The latest UK Food Standards Agency Consumer Attitudes Survey (FSA 2008) reveals that when prompted 32% of consumers state that they are concerned about the use of pesticides to grow food. It is very easy to find scare stories in the media and on the internet of pesticide exposure being “linked” to a wide variety of dreadful diseases and medical conditions such as cancer, neurodegenerative diseases, sterility and diabetes (see Box 1). The clear implication being that eating food containing pesticide residues will increase the chances of contracting such a disease. However this is completely at odds with the fact that there are no recent verified reports in the scientific literature of negative impacts on human health owing to the consumption of pesticide residues in food.

The relative toxicity of pesticides

The foundations of modern toxicology were laid over 500 years ago by the Swiss physician Paracelcus who famously said (Wikipedia 2011a): “All things are poison and nothing is without poison; only the dose permits something not to be poisonous”

25

6/4/11

12:39

Page 1

scientific In other words any substance can be poisonous if the dose is high enough, and even the deadliest toxins can be completely benign if the dose is small enough. It would seem that most members of the public have a strong negative perception about what pesticide residues in their food are doing to their health. Most people have little idea how toxic modern day pesticides actually are relative to other compounds to which they are commonly exposed, nor do the public generally know how much pesticide residue they are actually exposed to in their diets. An objective examination of these two factors is instructive.

In Fig. 2 (below) the toxicity of the world’s best selling pesticides in 2009 is plotted against the year of first introduction of the pesticide. The measure of toxicity used is the rat acute oral LD50 (see Glossary), which is the most common measure of toxicity used in scientific literature. It might be argued that an analysis of chronic toxicity would be more relevant to the discussion of pesticide residues in food, but in fact a comparison of acute toxicity should be a tougher test since pesticides are designed to show high levels of acute toxicity to their target organisms.

The top dotted line across the graph represents the toxicity of the over-thecounter medicine ibuprofen (rat acute oral LD50 of 636 mg/kg, (Science Lab 2011a; Oxford Univ. 2011a)).

Ibuprofen is not generally regarded as

a particularly “toxic compound” and yet an examination of the graph shows that it is more toxic than all but 13 of the world’s best selling pesticides. Moreover, it is more toxic than all but two of the world’s major fungicides (metalaxyl and cyproconazole) and all but one of the world’s major herbicides (paraquat). A good answer to the question “how toxic are modern day pesticides?” is that they are about as toxic as over-the-counter medicines.

The level of pesticide residue present in a normal adult diet is approximately 0.1 mg/day, roughly equivalent to a single grain of fine sand (Ames and Gold 2000). That is the total cumulative exposure to all pesticides, not exposure to each individual one. An examination of any packet of ibuprofen will reveal that patients are advised not to exceed a dose of 1 200 mg of ibuprofen in 24 hours. To consume an equivalent dose of pesticide residue through eating a normal diet at only 0.1 mg of pesticide residue per day would take 12 000 days, which is over 32 years! Taking ibuprofen over the course of several days to alleviate the symptoms of a common cold, for example, can easily lead to more than the equivalent of a lifetime exposure to pesticide residues in food. And yet if ibuprofen was a pesticide it would be amongst the most toxic pesticides in major use today.

The lower dotted line on the graph indicates the toxicity of caffeine (rat

acute oral LD50 of 192 mg/kg, (Fisher Science, 2011; Oxford Univ, 2011b)).

Caffeine is almost as toxic as paraquat (rat acute oral LD50 of 129-157 mg/kg), and only a handful of the world’s most toxic major insecticides are significantly more toxic than caffeine. And yet dietary exposure to caffeine can easily be many thousands of times greater than our exposure to pesticide residues in our food. A single can of cola contains over 30 mg of caffeine so it would take about a year to consume the same amount of pesticide residue eating a normal diet. A single cup of coffee can contain over 100 mg of caffeine (Wikipedia 2011b). Between 2000 and 2008, 721 people were admitted to the Emergency Department of the Royal Infirmary of Edinburgh suffering from a toxic overdose of caffeine (Waring et al., 2009).

Another remarkable fact is that sodium chloride (common salt) is close to the median level of toxicity of the world’s best selling pesticides. The rat acute oral toxicity of salt is 3000 mg/kg (Oxford Univ. 2011c; Science Lab 2011b) which means that by this measure it is more toxic than 19 of the 44 pesticides considered in this analysis. The UK National Health Service estimates that the typical consumption of salt in the UK is around 9.5 g per day, an exposure level approximately 95 000 times greater than typical exposures to pesticide residues in food. The maximum recommended daily dose of salt for adults is 6 g per day (NHS 2011).

The hazards associated with pesticide toxicity

Fig. 2: Toxicity of the world’s best selling pesticides in 2009 plotted against their year of first introduction (Sources: The Pesticide Manual (Tomlin 2009) and Phillips McDougall 2010). The graph shows the toxicity of the 15 best selling herbicides, the 15 best selling insecticides and the 14 best selling fungicides. The lower the number on the vertical axis (ordinate) the greater the toxicity, so toxicity is increasing down the graph. (N.B. all “copper-based fungicides” are omitted from the analysis because the sources considered them as a single entry, whereas in fact the different forms of copper used as fungicides exhibit a wide variation in toxicity, see Plate 1). Where toxicity is given as a range, or a difference is observed between male and female rats, the most toxic value is used, hence the graph portrays a worst case scenario.

It is very difficult to find verified cases of poisoning through ingestion of pesticide residues in food in the peer reviewed scientific literature (a conclusion also reached by Hall 1992). There were a number of cases reported in the 1950s and 1960s of poisonings owing to the consumption of pesticide contaminated grain, but it seems that in every case the contamination was either accidental (occurring post-harvest) or through fungicide treated seeds intended for planting ending in the human food chain (WHO 1990).

Whilst the situation has been clear in recent times, it has not always been so. In the early days of chemical pesticides a century ago, non-biodegradable inorganic chemicals containing toxic elements such as arsenic, mercury and lead were often sprayed in high concentrations over food crops to control pests. The impact on human health from the use of these pesticides remains disputed, with some studies suggesting that even for these com-

WORLD AGRICULTURE

25

26

6/4/11

12:40

Page 1

scientific pounds the doses of residue in food were too low to have any significant impact (Krieger 2005). Nevertheless these compounds were largely replaced by much more effective and less toxic pesticides based on organic chemicals around the middle of the 20th century, and the use of pesticides based on toxic inorganic substances has subsequently been banned, or severely restricted, in most regions of the world (Peryea 1998). Nevertheless many people still believe that modern day pesticides are still highly toxic and this view is perpetuated by certain NGOs (see Box 1 below).

Organic farming eschews the use of chemical pesticides of all types but grudgingly accepts that in some situations there is no practical alternative (Soil Association 2011): “Occasionally, despite the best efforts of the farmer, problems may arise that can't be solved by using the practices that we recommend.... Under these circumstances there are some pesticides that can be used by the farmer as a last resort.”

When pesticides have to be used, the only ones allowed are from natural sources: extracts of natural products, live bacteria, or naturally occurring

minerals. This is ideological dogma, since in many cases these natural pesticides are more toxic and/or more environmentally damaging, not to mention far less effective, than modern day synthetic pesticide alternatives.

One example of this is the use of copper based fungicides, which are generally rather toxic relative to synthetic fungicides (tribasic copper sulfate is more toxic to rats than paraquat) and are also obviously not broken down in the environment and hence present a persistent threat. Furthermore copper based fungicides are generally applied at a rate of several kilograms per hectare which is enough to turn sprayed foliage and fruit blue (Fig. 3).By comparison, modern day synthetic fungicides are generally less toxic, less environmentally persistent and are more effective even when applied at concentrations ten times lower. Another example is nicotine which may be used as an insecticide in organic farming in some parts of the world in the form of “tobacco tea” (IFOAM 2011). Nicotine, with a rat acute oral LD50 of 50 mg/kg (Science Lab 2011c; Oxford Univ. 2011d), is more toxic than all but two of the world’s best selling synthetic pesticides.

A commonly misunderstood concept

is the Maximum Residue Level (MRL).

It is often considered to be an absolute safety standard and hence food containing pesticide residues exceeding the MRL is considered dangerous to eat. In fact the MRL is not a safety standard: it is a production standard intended to facilitate international trade and is simply an indicator of whether or not the pesticide has been used in accordance with the manufacturers’ recommendations. The MRL is also generally set at the 95th percentile. In other words if the pesticide has been used in accordance with the instructions, 95% of treated crops will have residue levels at or below the MRL. This also means that even if the pesticide has been used as instructed, it is to be expected that about 5% of treated crops will contain residue levels above the MRL. In fact the proportion of MRL exceedances is generally somewhat lower, as many farmers will not apply the maximum allowable amount of pesticide, nor leave the minimum allowable time between application and harvest (assumptions which are made in the definition of the MRL).

This is indeed what is observed: in a comprehensive survey of pesticide residues in food in Europe in 2008, 96.5% of over 70 000 foodstuffs tested contained residue levels at or below the MRL (European Food Safety Authority 2010) and in fact the survey actively targeted foodstuffs where it was felt that MRL exceedances would be most likely.

However this does not necessarily mean that the remaining 3.5% of foodstuffs containing residues exceeding the MRL present a significant risk to the consumer. Further analyses showed that less than 0.2% of the foodstuffs tested had the potential to deliver doses of pesticide exceeding the “acute reference dose” (see Glossary) to individuals consuming very high quantities (> 97.5th percentile of general consumption) of the food in question. Even then the acute reference dose is only 1% of the highest dose shown to be harmless to animals in controlled trials. The risk of acute poisoning by pesticide residues in food is vanishingly low.

Box 1: Quotes from websites regarding the toxicity of pesticides (all accessed 27th January 2011

26 WORLD AGRICULTURE

But what about the risk of chronic health effects as a result of long term, low level exposure to pesticides? For every pesticide, long term animal studies must be conducted to define an “Acceptable Daily Intake” (ADI, see Glossary). The ADI is typically set between 0.1% and 1% of the “No Observed Adverse Effect Level” (NOAEL see Glossary). A set of highly conservative assumptions are then made about the exposure of consumers to the pesticide in food (for example, the pesticide will achieve

27

6/4/11

12:40

Page 1

scientific How naturally toxic is our food?

Plate 1: Grapes treated with copper based fungicide in the Côte du Rhône region of France, showing blue-green copper deposits on the fruit and leaves (photo kindly provided by Robert Cook)

100% market share on every crop for which it is approved, all uses of the pesticide are at the maximum application rate and minimum time before harvest and no degradation of residues occurs during storage, processing or cooking). In fact these assumptions are so conservative that in practice it is very difficult to consume doses of residue anywhere near the ADI for any given pesticide. A comprehensive survey by the New Zealand government in 2003/4 showed that for over 90% of pesticides, typical dietary exposure is less than 0.1% of the ADI (NZFSA 2005). Similar results have been reported from Australia (FSANZ 2003).

This means that human dietary exposure levels are therefore generally at least 100 000 to 1 000 000 times lower than the NOAEL. It should be noted that all concentrated formulations of pesticides should be treated with extreme care.

Formulations are designed to optimise the uptake of the pesticide into biological organisms but they can also facilitate uptake into humans through skin contact. The lack of appropriate protective equipment or carelessness when handling concentrated formulations can lead to accidental exposure corresponding to potentially toxic doses. Data from the WHO indicate that acute poisoning owing to accidental exposure to pesticides is a major problem in the developing world. Precise numbers are difficult to obtain but the indications are that over a million cases of accidental pesticide poisoning occur annually and the

real figure could be many times higher than this (Jeyaratnam 1990; WHO 1990). In contrast there are relatively few reports of accidental exposure in the developed world. Between 1945 and 1989 in England and Wales only 0.31% of total fatal poisonings were due to accidental exposure to pesticides (Casey and Vale 1994). This indicates that it is generally possible to use these compounds safely so long as care is taken and adequate control measures are in place.

Whilst the focus of this paper is on the human toxicological consequences of consuming pesticide residues in food, it should also be noted that modern day pesticides are also rigorously tested to ensure that the impact of their use on the environment is acceptable. This includes their toxicity to non-target organisms, for example earthworms and pest predators in the field, pollinator species such as honeybees, aquatic organisms such as fish and prey species at the bottom of the food chain such as water fleas (Daphnia).

It is also critically important to assess how long pesticides survive in the environment, how likely they are to move through the soil and get in to groundwater, and to understand their metabolic fate and the impacts of potential metabolites (UK Health and Safety Executive website). The total cost of the environmental and dietary safety testing that must be carried out by law on each pesticide is of the order of £100 million.

Every mouthful of food that we eat contains thousands of natural chemicals. Many of these chemicals are more toxic than modern day pesticides and are present in food at higher concentrations. This has been the case since humans first evolved and we have therefore evolved efficient mechanisms to deal with low concentrations of mildly toxic materials ingested in our diet. A good example is the glycoalkaloid content of potato. Solanine is one of the main toxic glycoalkaloids produced by potatoes, and it is comparable in toxicity to the more toxic major pesticides (rat acute oral LD50 of 590 mg/kg (Swinyard and Chaube 1973)). However solanine is found in potatoes in vastly higher concentrations than pesticide residues.

Depending on the variety, solanine levels can easily exceed 50 mg/kg of potato even after peeling (Friedman et al. 2003), and if the potatoes are allowed to “green” in light then the solanine levels can triple (Dao and Friedman 1994), reaching potentially toxicologically relevant doses in people eating even moderate quantities.

Another example is the psoralens found in celery. Psoralens are toxins that are activated by light. In the absence of light they are reasonably toxic (rat acute oral LD50 of 300-600 mg/kg), but in the presence of light they are far more poisonous: as little as 1 mg per kilo of body mass can be dangerous to humans (Capinera 2006). In one reported case a woman ate approximately 450 g of celery about an hour before visiting a suntan parlour. She suffered a severe, generalised phototoxic reaction resulting in serious blistering of the skin.

Subsequent analysis suggested that she had consumed a dose of approximately 45 mg of psoralens in the celery (Ljunggren 1990).

Pesticide residues and food safety

Pesticide exposure is often “linked” in the media to serious medical conditions. The evidence for these linkages only comes from studies involving high dose exposure: either animal studies or reports of human exposure to concentrated pesticide formulations. It is scientifically unjustifiable to extrapolate from high dose studies to the ultra low dose exposures that are present in our diet (Ames et al. 1987).

There is no good evidence that exposure to pesticide residues in food increases the incidence of these diseases. In fact if anything cancer rates have been declining during the period that synthetic pesticides have become widely used, perhaps owing to

WORLD AGRICULTURE

27

28

6/4/11

12:41

Page 1

scientific ‘Some of the most poisonous substances known to science are mycotoxins produced by fungi that grow on food crops’ improving diets as food becomes more affordable (Trewavas 2004).

The use of pesticides in agriculture makes the resulting foods safer to eat, not more dangerous. Firstly an innate resistance to pest attack in crops is an important component of pest control but a significant reduction, or elimination, of the use of pesticides will require the development of highly pest resistant crop varieties. This begs an obvious question: why are some vari-

eties of crop more resistant to pests than others? The answer is often that resistant crops produce higher concentrations of more noxious natural chemicals as their own internal pesticides. In some cases, plant breeding programmes designed to develop more pest resistant varieties of crops have inadvertently led to increasing the concentration of such compounds to dangerous levels. A good example of this is again that of psoralens in celery: a major grower developed and

Table 1: Toxicity of the world’s best-selling pesticides in 2009.

(Original data for those presented in Figure 2) a Data taken from Phillips McDougall 2010. b Data as reported in The Pesticide Manual (Tomlin 2009). c Logarithm of the lowest value (either of the range or male/female) of the LD50 data. d Toxicity data for metalaxyl-M. e Toxicity data for thiophanate-methyl. f Toxicity data for glyphosate-ammonium.

28 WORLD AGRICULTURE

introduced a new, highly insect resistant strain of celery into the market which caused rashes on people who handled the crop and were then exposed to light. The insect resistant celery was found to contain concentrations of psoralens nearly eight times normal levels (Ames and Gold 2000).

These natural pesticidal compounds produced by crop plants have obviously not been optimised to have low mammalian toxicity like modern synthetic pesticides. In fact in most cases these compounds have not yet even been identified, let alone tested for toxicity. Moreover, it has been shown that the production of natural toxic chemicals in crops can be induced by pest attack, significantly increasing their concentration in food (Hlywka et al. 1994), emphasising the importance of crop protection for food safety. The health consequences of eating a diet rich in crops with intrinsically high levels of pest resistance are unknown.

Secondly it is often forgotten that in the days before pesticides, food was often contaminated with high concentrations of extremely toxic natural chemicals that poisoned huge numbers of people. Some of the most poisonous substances known to science are mycotoxins produced by fungi that grow on food crops. For example aflatoxins are the most potent carcinogens known to science. The consumption of aflatoxin contaminated maize killed 80 people in Kenya in 2004 and hospitalised 180 others (BBC 2004).

The condition known as “St. Antony’s fire” caused by consumption of ergot alkaloids in rye was very common in the Middle Ages, with 132 recorded epidemics in Europe between the 6th and 18th centuries. Ochratoxins are produced by fungus that can grow on food in storage, and can cause aggressive cancers of the bladder and urinary tract (Bennett and Klich 2003).

Fusarium is a fungus that produces a cocktail of toxins which can contaminate wheat grain, one of which (fumonesin) has the potential to liquefy the brain tissue of horses eating contaminated feed (Dutton 2009)!

The elimination of these toxins from our diet relies upon effective control of not only the toxin-producing fungi, but also insects which can damage plant tissue facilitating secondary fungal attack. The use of effective modern day fungicides and insecticides is the most certain way of achieving this.

29

6/4/11

12:41

Page 1

scientific

Colorado beetle and offspring on potato leaves

WORLD AGRICULTURE

29

30

6/4/11

12:42

Page 1

scientific Conclusions Modern day pesticides are much less toxic than is commonly thought. They are comparable in toxicity to more familiar substances, such as over-the-counter medicines and common salt. They are less toxic and are found in lower concentrations than many compounds found naturally in food. Nevertheless modern pesticides are often erroneously thought to be deadly toxins, negatively impacting human health owing to the presence of residues in food and this view is deeply ingrained in the public consciousness. Most people do not realise that the amount of pesticide residue to which they are exposed is many orders of magnitude too low to have any impact on their health whatsoever.

However, today in the developed world it seems that no levels of risk in our daily lives are deemed acceptable.

Unachievable absolute guarantees of 100% safety are demanded and it is increasingly being proposed that the dominant paradigm by which new technology should be regulated is the precautionary principle (Pesticide Action Network 2011). This would lead to technologies being banned even in the absence of a credible causal link between the technology and any purported detrimental side effects, and irrespective of the benefits that the technology may bring. The essential benefits pesticides bring to global agriculture and food production are not widely appreciated. If pesticides are as dangerous and unnecessary as they are widely portrayed, then why are they used almost universally in commercial agriculture? The public seem unable to reconcile this contradiction.

Several NGOs and other groups with a “green� political agenda have been very effective in influencing public opinion against the use of pesticides. This is in turn is driving changes in the legislation of pesticides within Europe and elsewhere that is making life difficult for farmers, whilst providing no benefits to consumers in terms of increased food safety. Indeed this could lead to increased levels of natural toxins in food and an increased reliance on food imported from outside Europe where there is less control over production methods. It is also pandering to the growing anti-science agenda in the developed world: a rejection of scientific rationalism in favour of a kind of holistic, alternative naturalism as the dominant philosophy. Such modes of thinking are generally deeply suspicious of science and technology, at worst rejecting it altogether, dismissing any positive contributions and amplifying the potential risks. In a world where it is critically important to inspire current and future generations of scientists to dedicate their professional lives to rising to the challenges facing humanity, such attitudes are profoundly unhelpful.

Monarch butterflies

30 WORLD AGRICULTURE

31

6/4/11

12:43

Page 1

scientific References

ADAS (2008) Evaluation on the impact on UK agriculture of the proposal for a regulation of the European Parliament and of the council concerning the placing of plant protection products on the market. European Crop Protection Association, Brussels. http://www.adas.co.uk/LinkClick.aspx?fileticket=BOSPfOEtvRs%3D &tabid=246 accessed 25 January 2011.

Ames, B.N., Magaw, R. and Gold, L.S. (1987) Ranking possible carcinogenic hazards. Science, 236, 271-280.

Ames, B.N. and Gold, L.S. (2000) Paracelsus to parascience: the environmental cancer distraction. Mutation Research, 447, 3-13.

Battisti, D.S. and Naylor, R.L. (2009) Historical warnings of future food insecurity with unprecedented seasonal heat. Science, 323, 240-244.

BBC (2004) Killer maize sparks Kenya alarm. http://news.bbc.co.uk/2/hi/africa/3802699.stm accessed 26 January 2011 Bennett, J.W. and Klich, M. (2003) Mycotoxins. Clinical Microbiology Reviews, 16 (3), 497-516.

Capinera, J.L. The Encyclopedia of Entomology, Volume 1, Dordrecht, Springer, 2006, p1557, ISBN 0 79 238 670 1. Available at: http://books.google.co.uk/ , accessed 26 January 2011).

Casey, P. and Vale, J.A. (1994) Deaths from pesticide poisoning in England and Wales: 1945-1989. Human and Experimental Toxicology, 13 (2), 95-101.

Cordell, D., Drangert, J.-O. and White, S. (2009) The story of phosphorus: global food security and food for thought. Global Environmental Change, 19 (2), 292-305.

Dao, L. and Friedman, M. (1994) Chlorophyll, chlorogenic acid, glycoalkaloid, and protease inhibitor content of fresh and green potatoes. Journal of Agricultural and Food Chemistry, 42, 633-639.

Denholm, I., Devine, G.J. and Williamson, M.S. (2002) Insecticide resistance on the move. Science, 297, 2222-2223.

Dutton, M.F. (2009) The African Fusarium/maize disease.

Mycotoxin Research, 25, 29-39.

European Food Safety Authority (2010) 2008 Annual Report on Pesticide Residues according to Article 32 of Regulation (EC) No 396/2005. European Food Safety Authority Journal, 8 (6), 1646.

FAO (2011) Food and Agriculture Organisation of the United Nations. http://faostat.fao.org accessed 26 January 2011.

Fisher Science (2011) Material Safety Data Sheet: Caffeine, Anhydrous, U.S.P./N.F. https://fscimage.fishersci.com/msds/ 95940.htm accessed 26 January 2011.

FSA (2008) Consumer Attitudes to Food Standards: Wave 8 UK Report Final. Food Standards Agency, London.

FSANZ (2003) The 20th Australian Total Diet Survey, Food Standards Australia New Zealand, Canberra, Wellington, ISBN 0 64 234 591 0. http://www.foodstandards.gov.au accessed 26 January 2011.

Foresight (2011) The future of food and farming. The Government Office for Science, London.

Friedman, M., Roitman, J.N. and Kozukue, N. (2003) Glycoalkaloid and calystegine contents of eight potato cultivars.

Journal of Agricultural and Food Chemistry, 51, 2964-2973.

Godfrey, H.C.J., Beddington, J.R., Crute, I.R., Haddad, L., Lawrence, D., Muir, J.F., Pretty, J., Robinson, S., Thomas, S.M. and Toulmin, C. (2010) Food security: the challenge of feeding 9 billion people. Science, 327, 812-818.

Green, R.E., Cornell, S.J., Scharlemann, J.P.W. and Balmford, A. (2005) Farming and the fate of wild nature. Science, 307, 550-555.

Hall, R.L. (1992) Toxicological burdens and the shifting burden of toxicology. Food Technology, 46 (3), 109-112.

Hlywka, J.J., Stephenson, G.R., Sears, M.K. and Yada, R.Y. (1994) Effects of insect damage on glycoalkaloid content in potatoes (Solanum tuberosum). Journal of Agricultural and Food Chemistry, 42, 2545-2550.

Hodgson, J.A., Kunin, W.E., Thomas, C.D., Benton, T.G. and Gabriel, D. (2010) Comparing organic farming and land sparing: optimizing yield and butterfly populations at a landscape scale.

Ecology letters, 13 (11), 1358-1367.

HSE (2011) UK Health and Safety Executive Chemicals regulation Directorate (CRD) Home Page. http://www.pesticides.gov.uk/ accessed 26th January 2011 IFOAM (2011) Criticisms and Frequent Misconceptions about Organic Agriculture: The Counter-Arguments. http://www.ifoam.org/growing_organic/1_arguments_for_oa/criticisms_misconceptions/misconceptions_no7.html accessed 14 February 2011.

Jeyaratnam, J. (1990) Acute pesticide poisoning: a major global health problem. World Health Statistics Quarterly, 43 (3), 139-144.

Krieger, R. (2005) Reviewing some origins of pesticide perceptions. Outlooks on Pest Management, 16 (6), 244-248.

Ljunggren, B. (1990) Severe phototoxic burn following celery ingestion. Archives of Dermatology, 126, 1334-1336.

Merotto Jr., A., Jasieniuk, M., Osuna, M.D., Vidotto, F., Ferrero, A. and Fischer, A.J. (2009) Cross-resistance to herbicides of five ALSinhibiting groups and sequencing of the ALS gene in Cyperus difformis L. Journal of Agricultural and Food Chemistry, 57, 1389-1398.

Nelson, G.C., Rosegrant, M.W., Koo, J., Robertson, R. et al.

Climate change: impact on agriculture and costs of adaptation.

Washington D.C., International Food Policy Research Institute, 2009, ISBN 9 780 896 295 35-3.

NZFSA (2005) 2003/04 New Zealand total diet survey: agricultural compound residues, selected contaminants and nutrients, Wellington, New Zealand Food Safety Authority, ISBN 0 47 829 801 3. www.nzfsa.govt.nz accessed 26 January 2011.

NHS (2011), How much salt is good for me?

http://www.nhs.uk/chq/Pages/1138.aspx?CategoryID=51&SubCat egoryID=167 accessed 26 January 2011.

Oerke, E.-C., Dehne, H.-W., Schönbeck, F. and Weber, A. Crop production and crop protection: estimated losses in major food and cash crops, Amsterdam, Elsevier, 1994, ISBN 0 44 482 095 7.

Oerke, E.-C. (2006) Crop losses to pests. Journal of Agricultural Sciences, 144, 31-43.

OneWorld website (2011) http://us.oneworld.net/node/ 152674/ accessed 26 January 2011.

Oxford Univ (2011a) Safety data for ibuprofen. http://msds.chem.ox.ac.uk/IB/ibuprofen.html accessed 26 January 2011.

Oxford Univ (2011b) Safety data for caffeine. http://msds.chem.ox.ac.uk/CA/caffeine.html accessed 26 January 2011.

Oxford Univ (2011c) Safety data for sodium chloride. http://msds.chem.ox.ac.uk/SO/sodium_chloride.html accessed 26 January 2011.

Oxford Univ (2011d) Safety data for nicotine. http://msds.chem.ox.ac.uk/NI/nicotine.html accessed 14 February 2011.

Peryea, F.J. (1998) Historical use of lead arsenate insecticides, resulting soil contamination and implications for soil remediation.

Proceedings of the 16th World Congress of Soil Science, Montpellier, France, 20th-26th August 1998.

Pesticide Action Network (2011) Promoting precaution. http://www.pan-uk.org/pestnews/Issue/pn53/pn53p10.htm accessed 2 February 2011.

Phillips McDougall (2010) Agriservice, Products Section – 2009 market. http://www.phillipsmcdougall.com accessed 19 January 2011.

Pivonia, S. and Yang, X.B. (2006) Relating epidemic progress from a general disease model to seasonal appearance time of rusts in the United States: implications for soybean rust. Phytopathology, 96 (4), 400-407.

Rickard, S. (2010) The value of crop protection: an assessment of the full benefits for the food chain and living standards, Crop Protection Association. http://www.cropprotection.org.uk/content/home.asp accessed 19 January 2011.

Ridoutt, B.G. and Pfister, S (2010) Reducing humanity’s water footprint. Environmental Science and Technology, 44, 6019-6021.

Royal Society. Reaping the benefits: Science and the sustainable intensification of global agriculture, London, The Royal Society, 2009, ISBN 9 78 085 403 784 1.

Sanchez, P.A. and Swaminathan, M.S. (2005) Cutting world hunger in half. Science, 307, 357-359.

Science Lab (2011a) Ibuprofen MSDS. http://www.sciencelab.com/msds.php?msdsId=9924344 accessed 26 January 2011.

Science Lab (2011b) Sodium chloride MSDS. http://www.sciencelab.com/msds.php?msdsId=9927593 accessed 26 January 2011.

Science Lab (2011c) L-Nicotine MSDS. http://www.sciencelab.com/msds.php?msdsId=9926222 accessed 14 February 2011.

Soil Association (2011) Pest control: How organic farming avoids pesticides. http://92.52.112.178/web/sa/saweb.nsf/ ed0930aa86103d8380256aa70054918d/67fd448ec0643610802571 49004cb42d?OpenDocument accessed 26 January 2011.

Swinyard, C.A. and Chaube, S. (1973) Are potatoes teratogenic for experimental animals? Teratology, 8 (3), 349-358.

Thomas, R.J. (2008) 10th Anniversary Review: Addressing land degradation and climate change in dryland agroecosystems through sustainable land management. Journal of Environmental Monitoring, 10, 595-603.

Tilman, D., Cassman, K.G., Matson, P.A., Naylor, R. and Polasky, S. (2002) Agricultural sustainability and intensive production practices. Nature, 418, 671-677.

Tomlin, C.D.S. (ed.) The Pesticide Manual, 15th Edition, Alton, British Crop Protection Council, 2009, ISBN 9 78 190 139 618 8.

Trewavas, A. (2004) A critical assessment of organic farmingand-food assertions with particular respect to the UK and the potential environmental benefits of no-till agriculture. Crop Protection, 23, 757-781.

Waring, W.S., Laing, W.J., Good, A.M. and Malkowska, A.M. (2009) Acute caffeine ingestion: clinical features in patients attending the Emergency Department and Scottish Poison Centre enquiries between 2000 and 2008. Scottish Medical Journal, 54 (4), 3-6.

WHO (1990), Public health impact of pesticides used in agriculture, Geneva, World Health Organisation, 1990, ISBN 9 24 156 139 4.

Wikipedia (2011a) Paracelsus. http://en.wikipedia.org/wiki/Paracelsus accessed 26 January 2011.

Wikipedia (2011b) Caffeine. http://en.wikipedia.org/wiki/Caffeine accessed 26 January 2011.

Zhang, W., Olson, E., Saintenac, C., Rouse, M., Abate, Z., Jin, Y., Akhunov, E., Pumphrey, M. and Dubcovsky, J. (2010) Genetic maps of stem rust resistance gene Sr35 in diploid and hexaploid wheat.

Crop Science, 50, 2464-2474.

Acknowledgements The author would like to thank Dr. Ray Elliott, Dr. Mike Bushell, Dr. Neil Lister, Judy Hughes and Jill Hughes for their help and suggestions in the preparation of this manuscript.

WORLD AGRICULTURE

31

32

6/4/11

12:44

Page 1

scientific

Feeding the world: a contribution to the debate Keith Goulding, Anthony Trewavas and Ken Giller Keith Goulding, Department of Sustainable Soils and Grassland Systems, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK. Anthony Trewavas, Institute of Molecular Plant Science, University of Edinburgh, Edinburgh EH9 3 JH, Scotland.

Ken Giller, Professor of Plant Production Systems, Wageningen University, Haarweg 333, 6709 RZ Wageningen, The Netherlands.

Summary It is often claimed by proponents of organic farming that, if used worldwide, it would provide sufficient food for a growing world population. Here we make a critical assessment of this claim for wheat, a major cereal crop and source of food throughout the world. We have compared organic and conventional systems, examined some of the publications and claims in detail, and found a typical ratio of organic:conventional wheat yields of 0.65. Nitrogen (N) fixation by legumes, the main source of N supply in organic systems, is shown to be much too small and variable to support large and consistent wheat yields. Our conclusion agrees with that of a recent report by the University of Reading’s Centre for Agricultural Strategy that organic agriculture cannot feed the world using current technologies. However, we believe that there is a need to reduce the over-optimal use of fertilisers and agricultural chemicals and to better manage crop rotations to reduce nutrient losses to the environment and crop losses to pests and diseases. There is also a wider societal need to reconsider diet in the context of health and the ability of world agriculture to supply the wants of its anticipated 9 billion population.

Key words: Organic farming, Conventional farming, Sustainable food supplies, Nitrogen fixation, Legumes, Wheat

Abbreviations

FYM, Farmyard Manure;

N, Nitrogen;

CAS, Centre for Agricultural Strategy, University of Reading;

NUE, Nitrogen Use Efficiency;

P, Phosphorus;

FAO, Food and Agriculture Organisation, United Nations;

K, Potassium; Mg, Magnesium;

S, Sulphur;

Introduction A recent paper by Badgley et al. (2007) claimed that organic farming, if used worldwide, would provide sufficient food for a growing world population.

This claim was based on a literature survey of: (1) a comparison of organic and conventional yields; (2) an assessment of the amounts of nitrogen (N) fixed by legumes. These were then used to calculate potential food production. The paper stimulated much critical response (see Cassman, 2007; Hendrix, 2007; Avery, 2007; Connor, 2008).

Badgley et al.’s (2007) evaluation was not related to any particular organic certification criterion, but the organic systems studied did rely greatly on the application of manure or the use of cover crops to replace fertiliser nitrogen. The use of manure and cover crops is not, of course, unique to organic farming systems; they are used by many ‘conventional’ (i.e. non-organic) farmers in the UK and beyond. Conventional farming is also very variable: UK farmers use a range of short or long rotations, minimum tillage or no tillage combined

32

WORLD AGRICULTURE

Organic: Conventional (yields): O:C. with ploughing, livestock fed on grass, grass/clover or other forms of fodder and returning variable amounts of manure, slurry and bought-in compost and other biosolids to the land. The actual practices on each farm result from long experience and with some, exceptions are usually site specific. Such managerial skill is crucial. All farmers take a holistic view of their farm, but the over-riding criterion is the market price for produce set against the cost of production. The primary goal of any farmer is to maximise income and maintain the quality of their land.

If arguments are to be made about feeding the world from organic farming then the primary concern must be the yield ratios of organic:conventional for the major cereal crops and livestock. Wheat is grown on ca 215 million ha worldwide, is tolerant of arid climates and, containing more protein than corn or rice, is one of the primary food staples. Therefore, for brevity and simplicity, we have made a critical assessment of the claims that organic farming can feed the world using wheat as an exemplar.

33

6/4/11

12:44

Page 1

scientific Organic vs conventional wheat yields

B

adgley et al. (2007) relied heavily on data from experiments not farmers’ fields.

While this is better than anecdotal information, there are some disadvantages: (1) experiments lack the economic drivers that determine what farmers actually do; (2) while yields from experiments are useful indicators of potential yield they are obtained under closely-controlled and often near-ideal conditions with scientific expertise that does not exist on practising farms; the difficulties of transferring experimental results to actual farming practice have long been recognised (Davidson and Martin 1968).

Additionally, Badgley et al. (2007) made no attempt to rate the credibility of the ratios of organic to conventional yield they presented.

Measurements made in just one year are presented as having the same credibility as those made over 10-25 years or more.

The correct way for the performance of organic farming to be compared with other forms of farming is to assess the averages from many farms over large areas and several years (see Jones and Crane 2009 and section 5 below). Although this information is available in the UK it does not seem to be available elsewhere. Figures from Elm Farm Research Centre, the primary organic research institute in the UK, indicate that the average UK organic winter wheat yield (assessed from data on many farms) is ca. 4 t ha-1 but about 8 t ha-1 for conventional agriculture; a ratio of organic:conventional (hereafter O:C) of 0.5 (see Lampkin and Measures 2001; Welsh et al., 2002).

Also, statistical methods were developed in the 1930's by Fisher (see Street, 1990) to enable researchers to measure differences in yields between farms and fields. Their use should be mandatory. An assessment of organic vs conventional food quality by Dangour et al. (2009) searched 52,471 potentially relevant articles and identified 162 studies (137 crops and 25 livestock products) that made the required comparisons; of these only 55 met the required statistical quality

Table 1: Comparison of ratios or organic: conventional wheat yields using publications referenced by Badgley et al. (2007) with those from references founded by the authors.

controls. Clearly rigorous data are lacking.

Badgley et al’s data Table 1 summarises the ratios of yields of O:C wheat for the data used by Badgley et al. (2007). To comment on just some of the references used to support a high O:C ratio (rows 1 and 2): Granstedt and Kjellenberg (1996) [O:C = 0.8] stated “The fertiliser application rates for the various treatments were adjusted to bring about comparable yields”.

Mader et al. (2002) [O:C = 0.87] used results from a long-running Swiss experiment, which applied manure at an organic regulation level of 1.4 animals ha-1 (and yielded about 4 t wheat grain ha-1). However, the fertiliser application of 125 kg N ha-1 to the ‘conventional’ treatment was well below the optimum. The conventional Swiss average wheat yield over 20 years, according to the FAO, is 6.5 t ha-1, which would give an O:C ratio of about 0.6. Mader et al.

(2002) state that “cereal yields under organic management are typically 6070% of those under conventional management”.

McGuire et al. (1998) [O:C = ratios 0.98, 0.93, 0.83, 0.81] studied cover crops on dryland organic farms over winter, but herbicides were used to control weeds and thus organic procedures were not followed.

National Research Council (1989) [O:C = 1.02] reviewed 'alternative' agriculture. But the aims of 'alternative' systems, as described on page 27 of the report, are not organic and would be subscribed to by many conventional farms in the UK (see for example LEAF (2010). In addition, the O:C ratio refers to the yields of two different rotations both of which received insecticides and are therefore not produced under an organic regime.

Nguyen and Haynes (1995) [O:C = 0.68] examined three pairs of farms and provided an estimate of an O:C ratio of 0.68 . The paper comments that soil nutrient reserves are being

WORLD AGRICULTURE

33

6/4/11

12:45

Page 1

scientific depleted rapidly at one of the farms.

Raupp and Konig (1996) [O:C = 1.01] stated “In order to achieve comparable yields with organic and mineral fertiliser, composted manure had to be used in relatively high amounts”, sometimes up to 60 tonnes ha-1.

New data We also examined the references in rows 3 and 4 of Table 1. To comment on a few of these: Bochenhoff (1986) found O:C ratios of 0.7 for winter wheat on 145 farms and 0.72 for spring wheat on 52 farms.

Yield t/ha

34

Grimm (1988) compared 40 'alternative' farms with over 800 conventional farms to give an average O:C ratio 0.69.

Higginbotham et al. (2000) and Trewavas (2004) reported results from the 10-year Boarded Barns Farms study, with certified organic and conventional matched fields over 7 years, which gave O:C ratios of 0.61, 0.75, 0.64, 0.65, 0.7, 0.61, 0.51, with an average of 0.64.

Ryan et al. (2004) reported O:C ratios of matched organic and conventional farms of 0.83, 0.37, 0.53 and 0.16.

Stoppler (1989) compared 23 varieties of wheat in organic and conventional agriculture and found O:C ratios of 0.75, 0.95 and 0.73, with an average of 0.81.

Data from the Broadbalk experiment at Rothamsted The 167-year old Broadbalk winter wheat experiment at Rothamsted is often used to ‘prove’ that crops fertilised with manure yield as well as those fertilised with chemically produced fertilisers and thus support organic farming. This comparison relates to two experimental treatments on Broadbalk, one given only moderate amounts of fertiliser N (144 kg N ha-1 yr-1 plus P, K, Mg and S) and the other 35 t ha-1 cattle manure (FYM; Figure 1). Badgley et al. (2007) referred to these experiments twice in their article under different references (e.g. Jenkinson et al. 1994) and used them as a supposed comparison of organic to conventional; the O:C ratio quoted was 1.15.

34 WORLD AGRICULTURE

Fig. 1: Yields of wheat grain for selected plots on the Broadbalk Experiment 1843-2008

The wheat yields from the 35 t ha-1 manure applied to the FYM plot on Broadbalk have matched those from moderate amounts of fertilisers (144 kg N ha-1 yr-1) within statistical variation over the lifetime of the experiment (Goulding et al. 2008) and are currently about 7 t ha-1; the true O:C yield ratio is thus 1. More importantly, (1) the manure-only experiment is not organic because substituting manure for fertiliser is not certified organic practice, besides which herbicides, insecticides and fungicides are used on Broadbalk; and (2) the fertilizers applied to the conventional treatment are not optimal. Best yields on Broadbalk currently average 9-10 t ha-1 yr-1 (but can be >11 t ha-1 yr-1 ) and are achieved either with optimum rates of N fertiliser at between 250 and 300 kg N ha-1 yr-1 or the manure PLUS an extra 96 kg N fertiliser ha-1 yr-1 in spring, the exact yields depending on seasonal weather and pests and diseases. FYM plus N fertiliser in spring produces a good yield but at the cost of very poor N use efficiency and large losses of nitrate to water, about 30% larger than those from the optimum fertiliser N application (Goulding et al.

2000).

Organic farmers can apply manure containing up to 250 kg N ha-1 yr-1 to any one field, but the farm average must be no more than 170 kg N ha-1 yr-1 (Soil Association 2009). The regulations on stocking rates are set to

achieve the same limits, with estimated outputs of N per animal.

The UK Fertiliser Recommendations (Defra, 2010) estimate that 1 t cattle manure contains 6 kg N. Thus an organic farmer could apply up to 40 t FYM ha-1 to any one field, but with an average of no more than 28 t ha-1 across the farm; similar to the amount applied to Broadbalk. Organic yields of up to 7 t ha-1 are therefore achievable with adequate pest, disease and weed control and if sufficient manure is available but the ethos of organic farming is not about replacing fertiliser with manure; it is based around crop rotations.

Another crucial point to note from the Broadbalk and other long-term experiments at Rothamsted, is that they were started in the mid-19th century because there was insufficient manure, even then, to provide nutrients for crop growth. To provide 35 tonnes of manure/ha requires 3.5 adult cattle ha-1. There are about 4 million adult cattle in the UK and 4 million ha of arable farmland.

(Respective figures in the USA are 100 and 200 million). Thus to provide sufficient manure for high wheat and other crop yields would necessitate increasing the numbers of cattle about 3.5 fold (7 fold in the USA). Their winter consumption of corn and wheat would increase by the same amount and the land devoted to food crops would have to decline. Methane production, a potent greenhouse gas, would also increase.

In summary, our literature analysis

35

6/4/11

12:46

Page 1

scientific

agrees with those of Offermann and Nieberg (2000) and Jones and Crane (2009 and Section 5 below) that organic wheat yields are ca two-thirds those of conventional systems (Table 1). Data from the Broadbalk Experiment and that of Raupp and Konig (1996; section 3.1) show that similar yields to conventional can be obtained from organic systems, but only by replacing fertiliser N with an equal amount of N in a very large application of manure, which is not good organic practice nor is it sustainable.

Legume nitrogen fixation Badgley et al. (2007) claim that N fixation by legumes could be sufficient to replace the current use of N in fertiliser. N fixation is a biological process subject to the vagaries of the weather as well as site-specific constraints such as the availability of other nutrients, notably P (Giller 2001). The mean amount of N fixation for cover crops, quoted by Badgley et al. (2007), is 100 kg N ha-1 with standard deviations of 33-95%. Of the N fixed, 66% was estimated to be mineralised and taken up and incorporated into grain. This is based on a single reference (Hoyt and

Hargrove 1986), who suggest that a selection of green manures (crimson clover, hairy vetch and Austrian winter peas) accumulated more than 150 kg organic N ha-1 and subsequently released 100 kg inorganic N ha-1 into the soil for the subsequent summer crop. This estimate, in turn, is based on data from US experiments of the early 1980s, most of which are referenced in Hoyt and Hargrove (1986) as 'unpublished'., If all of the 100 kg N ha-1 that Badgley et al.

(2007) estimate to be fixed by cover crops is utilised, this would be enough for about 6 t ha-1 of wheat and 10 t ha-1 maize (Raun and Johnson 1999), but this is unlikely. Even if the N-use efficiency of 66% is accepted, this would provide sufficient N to produce only about 4 t ha-1 wheat and 6-7 t ha-1 maize.

World-wide, the efficiency of use of N from fertiliser is 33%, a figure easily calculated from the fertiliser N used in agriculture and the N that ends up in seed (Raun and Johnson 1999). What is the actual N-use efficiency from a grass-clover ley or a legume green manure? A number of papers place the figure at 20% or less (Giller and Cadisch 1995; Harris et al. 1994; Kramer et al. 2002; Ladd and Amato

1986). Others report that only 9-33% of the legume N incorporated into the soil the previous year is taken up into the crop, let alone translocated into the grain (Muller 1987, 1988a,b; Ladd et al. 1983). Berry et al. (2002) used a well-established relationship between soluble soil N and the protein content of wheat seed and showed that, in an organic soil containing a potential 300 kg N ha-1, the wheat plant only appeared to be able to access 50-60 kg N ha-1, i.e. a Nitrogen Use Efficiency of about 20%. It can be argued that, over the long-term, legume fixed N not utilised in grain will build up soil N and thus increase the yield in the long-term. However, on the long-term Ley-Arable Experiments at Rothamsted and Woburn, organic C in soil (and, by inference N) increased by only 1020% after 30-60 years of a 3-year grass-clover ley followed by 2/3-years’ arable crops (Johnston et al. 2009).

Using a more realistic N-use efficiency of 20%, the 100 kg N ha-1 would yield only about 1 t ha-1 wheat or 2 t ha-1 maize, and no more than 60-80 kg protein ha-1. This is enough to support about 4-5 people ha-1 on a very simple vegetarian diet (Smil 2001).

WORLD AGRICULTURE

35

36

6/4/11

12:48

Page 1

scientific basis of area, or the number of farm holdings (Table 2; full data are in Jones and Crane 2009; Table 17, page 49).

Weighting according to area did not take into account the fertility building phase of crop production whereas weighting by farm holding did. This approximately halves the yield on an area basis over a rotation and gives the potential for self-sufficiency in wheat as ca 33%.

Table 2. Estimates of the potential organic production if all farms were organic as a percentage of current conventional production in England and Wales, weighted by farm type. (Adapted from Jones and Crane, 2009).

Badgley et al. (2007) reference Kramer et al. (2002) as indicating that a legume cover crop can provide the same yield as mineral fertiliser.

However, Kramer et al. achieved this by using a mixture of a vetch cover crop together with 330 kg N ha-1 from turkey manure, providing a total of 435 kg N ha-1 compared with a conventional fertiliser application of about half that value. The N content of the turkey manure is equivalent to that in about 47 t ha-1 cattle manure; an amount that cannot be supplied sustainably.

demand. Mineralisation also continues throughout the season and beyond the growth period in late summer and autumn, putting N at risk of loss to air and water during periods of rainfall through autumn to spring (Goulding et al. 2000); leaching of N from organic and conventional farms is now known to be similar in magnitude (Goulding 2000; Trewavas 2004).

Some have suggested that the risks of eutrophication and global warming potential from organic farms are higher than from conventional farms (Williams et al. 2006).

In addition to the amount of N supplied in organic rotations, there is a lack of synchrony of mineralisation of organic nitrogen with crop requirements. Wheat, for example, needs to take up much of the N very quickly in spring to form the leaf canopy. Spring applications of soluble fertiliser easily meet that requirement.

Mineralisation of soil organic N certainly occurs in spring, but not usually quickly enough to meet crop

The UK’s capacity to produce food under organic agriculture Jones and Crane (2009) sought to calculate the ability of organic agriculture to supply the UK with a range of agricultural products. They took a selection of representative organic farms and multiplied up current organic yields/outputs on the

The authors conclude that “…it would be unfair to ask if an organic agriculture could feed the nation, for obviously it could not, at least not with current technologies.” But then neither does conventional agriculture under the current regime. “The real problem for organic agriculture would be the supply of eggs, poultry and pig meat….Also problematic would be the current decline in demand for red meats,…” . This is simply because in order to meet the N requirements for wheat, the rotational organic systems would supply, according to CAS figures ca 170% of the beef and 160% of the sheep meat we currently eat.

As stated realistically by Woodward and Meier-Ploeger (1999), who are strong proponents of organic farming, but also highly critical of what might be called the ‘colour supplement’ view of organic food, they emphasise that the debate cannot focus on whether organic farming can feed the world.

The debate must focus on whether the world can adapt its diet and markets to systems such as organic that require less non-renewable inputs, but produce sufficient calories for a balanced diet.

Plate 1: Harvesting on Broadbalk. An historical photograph

36 WORLD AGRICULTURE

37

6/4/11

12:48

Page 1

scientific Discussions and Conclusions The mineralisation of soil organic matter and crop residues is clearly an important source of N for crops but, to sustain the yields necessary to feed a growing world population, this must be augmented by fertilisers and manures where available. Soluble fertiliser can much more accurately provide nutrients when the growing crop needs it (synchronisation), whereas organic material improves soil structure, water holding capacity, microbial diversity and root development. Claims that fertilisers damage the soil (reiterated by Badgley et al. 2007) were first made by Steiner (Pfeiffer 1940) can be rejected, as the Broadbalk Experiment clearly shows.

Connor (2008) calculated the carrying capacity of organic agriculture at 3–4 billion people.

From our own review of the literature, Connor’s (2008) paper, and the recently-published report from the CAS (Jones and Crane 2009), one must conclude that organic agriculture cannot feed the world in the way that it is now fed and seems increasingly wished to be fed. Rapidly developing populations in India and China want more and better food, especially more meat.

Organic food is more expensive, often greatly so, the higher price being compensation for lower yields and greater variation and greater risk of crop loss. Any attempt to convert world agriculture to organic production would increase world food prices enormously, and those most at risk would be the poorest nations that are unable to provide sufficient produce of their own.

However, there is always room for improvement in all kinds of farming and we have no difficulty in agreeing with Badgley et al.

(2007) about the need to improve soil quality by adding organic material, reducing unnecessary use of fertilisers and agricultural chemicals, and optimising rotations to reduce losses to pests and diseases. And both organic and conventional systems will have to develop and adapt to predicted climate change.

Plate 2: Now in its 168th year, the Broadbalk Wheat Experiment compares organic manures with fertilisers supplying the major plant nutrients for their effects on the yield of winter wheat. The field consists of plots 320 m long by 6 m wide. The photograph shows very clearly the main effect of nitrogen on yield. The palest plots towards the RHS received no or very small amounts of nitrogen whereas the darkest green plots were provided with excessive amounts of farmyard manure (far RHS) or large amounts (>200 kg ha-1 yr-1, LHS) of nitrogen fertiliser.

WORLD AGRICULTURE

37

38

6/4/11

12:49

Page 1

scientific References

Avery, D. (2007) Organic abundance report: fatally flawed. Commentary. Centre for Global Food Issues. http://www.thetruthaboutorganicfoods.org /2007/09/14/%e2%80%9corganic-abundance%e2%80%9d-report-fatally-flawed/ (Accessed 10 February 2011).

Badgley, C., Moghtader J., Qunitero, E., Zakern, E., Chapell, J., Avile´s-Va´zquez, K., Samulon, A. and Perfecto, I. (2007). Organic agriculture and the global food supply.

Renewable Agriculture and Food Systems, 22, 86-108.

Berardi, G.M. (1978). Organic and conventional wheat production - examination of energy and economics. Agro-Ecosystems, 4, 367-376.

Berry, P.M., Sylvester-Bradley, R., Philips, L., Hatch, D.J, Cuttle, S.P., Rayns, F.W. and Gosling, P. (2002). Is the productivity of organic farms restricted by the supply of available nitrogen? Soil Use & Management. (supplement), 18, 248-256.

Bochenhoff, E. (1986). Analyse der Beitrebs und Produktionsstrukturen sowie der Naturalertrage Imalternativen Landbau Berichte uber Landwirtschaft, 64, 1-39.

Cassman, K.G. (2007) Editorial response

by Kenneth Cassman: can organic agriculture feed the world—science to the rescue?

Renewable agriculture and Food systems, 22, 83-4.

Connor, C.J. (2008). Organic agriculture cannot feed the world. Field Crops Research, 106, 187-190.

Dangour, A.D., Dodhia, S.K., Hayter, A., Allen, E., Lock, K. and Uauy, R. (2009).

Nutritional quality of organic foods: a systematic review. American Journal of Clinical Nutrition (published online ahead of print 29 July 2009), 6pp. doi: 10.3945/ajcn.2009.28041.

Davidson, B.R. and Martin, B.R. (1968).

Experimental research and farm production.

Ag-Econ Res. Report No 7. University of West Australia Press Nedlands, West Australia.

Defra (2010) Fertiliser Manual (RB209). 8th edition. TSO, Norwich.

Dlouhy, J. (1981). Alternative forms of Agriculture- Quality of Plant Products from Conventional and Biodynamic Growing.

Report 91. Department of Plant Husbandry, Swedish University of Agricultural Sciences.

Uppsala. 143 pp.

Entz, M.H. Guildford, R. and Gulden, R. (2001). Crop yield and soil nutrient status on 14 organic farms in the eastern portion of the northern Great Plains. Canadian Journal of Plant Science, 81, 351-354.

FAO. (2002) Selected Indicators of Food and Agriculture Development in Asia-Pacific Region - 1991-2001. Food And Agriculture Organization Of The United Nations Regional Office For Asia And The Pacific, Bangkok, Rap Publication: 2002/19.

Giller, K.E. (2001). Nitrogen Fixation in Tropical Cropping Systems. CAB International, Wallingford.

Goulding, K.W.T. (2000). Nitrate leaching from arable and horticultural land. Soil Use and Management, 16, 145-151.

Goulding, K.W.T., Poulton, P.R., Webster, C.P. & Howe,M.T. (2000). Nitrate leaching from the Broadbalk Wheat Experiment, Rothamsted, UK, as influenced by fertilizer and manure inputs and the weather. Soil Use & Management, 16, 244-250.

Goulding, K.W.T., Jarvis, S.C.J. and Whitmore, A.P. (2008). Optimising nutrient management for farm systems. Philosophical Transactions of the Royal Society of London, Series B, 363, 667-680.

Gransted, A.G. and Kjellenberg, L. (1996).

Quality investigations with the K trial, Jarna and other Scandanavian fertilisation experiments. In Quality of Plant Products Grown with Manure Fertilisation Ed: J. Raupp. Volume 9. Institute for Biodymanic Research. Darmstadt. pp.3-12.

Grimm, M. 1988. Zum Agrarbericht (1988). Lebendige Erde, 3, 166-169.

Harris, G.H., Hesterman, O.B., Paul, E.A., Peters, S.E. and Janke, R.R. (1994). Fate of legume and fertiliser 15N in a long term cropping systems experiments. Agronomy Journal, 86, 910-915.

Hendrix, J. (2007) Editorial response by Jim Hendrix. Renewable agriculture and Food systems, 22, 84-5.

Higginbotham, S., Leake, A.R., Jordan,

38 WORLD AGRICULTURE

V.W.L. and, Ogilvy, S.E. (2000).

Environmental and Ecological Aspects of Integrated, Organic and Conventional Farming Systems. Aspects of Applied Biology, 62, 15-20.

Hoyt, G.D. and Hargrove W.L. (1986).

Legume cover crops for improving crop and soil-management in the southern unitedstates. Hortscience, 21, 397-402.

Jenkinson, D.S., Bradbury, N.J. and Coleman, K. (1994). In: Long-term Experiments in Agricultural and Ecological Sciences. Eds. R.A.Leigh, and A.E. Johnston.

CAB International, Wallingford, UK. pp. 117138.

Johnston, A.E., Poulton, P.R. and Coleman, K. (2009). Soil organic matter: its importance in sustainable agriculture and carbon dioxide fluxes. Advances in Agronomy, 101, 157.

Jones, P. and Crane, R. (2009) England and Wales under organic agriculture. How much food could be produced? CAS Report 18.

Centre for Agricultural Strategy, Reading, 66pp.

Kitchen, J.L., McDonald, G.K., Shepherd, K.W., Lorimer, M.F. and Graham, R.D. (2003). Comparing wheat grown in South Australian Organic and Conventional wheat farming systems. 1. Growth and Grain Yield.

Australian Journal of Agricultural Research, 54, 889-901.

Kramer A.W., Doane, T.A., Horwath, W.R. and van Kessel, C. (2002). Combining fertiliser and organic inputs to synchronise N supply in alternative cropping systems in California. Agriculture Ecosystems and Environment, 91, 233-243.

Ladd, J.N. and Amato, M. (1986). The fate of nitrogen from legume and fertiliser sources in soils successively cropped with wheat under field conditions. Soil Biology and Biochemistry, 18, 417-425.

Ladd J.N., Amato, M., Jackson, R.B. and Butler J.H.A. (1983). Utilisation by wheat crops of nitrogen from legume residues decomposing in soils in the field. Soil Biology and Biochemistry, 15, 231-238.

Lampkin, N. and Measures, M. (2001).

Organic Farm Management Handbook. WIRS, Aberystwyth and EFRC Newbury.

LEAF (Linking Environment And Farming) (2010) LEAF’s Integrated Farm management (IFM). LEAF, Stoneleigh, Warwicks, UK. (http://www.leafuk.org/ leaf/farmers/LEAF's%20IFM.eb) Leu, A.F. (2004). Organic Agriculture Can Feed the World. Acres, USA, Vol. 34, No1.

Levi, M. (1979). Principles of Bio-Organic Agriculture. The Biosphere, 8, 30-35.

Lockeretz, W., Shearer, G. and Kohl, D.H. (1981). Organic farming in the corn belt.

Science, 211, 540-547.

Mader, P., Fliessbach, A., Dubois, D., Fried, P. and Niggli, U. (2002). Soil fertility and biodiversity in organic farming. Science, 296, 1694-1697.

Mason, H.E., Navabi, A, Frick, B.L. O'Donovan, J.T. and Spaner D.M. (2007). The Weed-Competitive ability of Canada western red spring wheat cultivars grown under organic management. Crop Science, 47, 11671175.

McGuire, A.M., Bryant, D.C., and Denison, R.F. 1998. Wheat yields, nitrogen uptake, and soil moisture following winter legume cover crop vs. fallow. Agronomy Journal, 90, 404–410.

Muller, M.M. (1987). Leaching of subterranean clover derived N from a loam soil.

Plant and Soil, 102, 185-191.

Muller, M.M. (1988a). The fate of clover derived 15N nitrogen during decomposition under field conditions: effects of soil type.

Plant and Soil, 105, 141-147.

Muller M.M. (1998b). The fate of clover derived nitrogen 15N during decomposition under field conditions. Effects of liming and fertilisation. Plant and Soil, 111,121-126.

National Research Council. (1989).

Alternative Agriculture. Washington, D.C. National Academy Press.

Nguyen, M.L. and Haines, R.J. (1995).

Energy and labour efficiency for three pairs of conventional and alternative mixed cropping farms in Canerbury, New Zealand.

Agriculture Ecosystems and Environment, 52,163-172.

Offermann, F. and Nieberg, H. (2000).

Economic performance of organic farms in Europe. Organic Farming in Europe: Economics and Policy, Vol 5, University of

Hohenheim, Stuttgart.

Pfeiffer, E. (1940). Biodynamic farming and gardening: soil fertility renewal and preservation. New York/London, Anthroposophic Press/Rudolf Steiner.

Poutala, R.T., Korva,J. and Varis, E. (1993).

Spring wheat cultivar performance in ecological and conventional cropping systems.

Journal of Sustainable Agriculture, 3, 63-83.

Raun, W.R. and Johnson, G.V. (1999).

Improving nitrogen use efficiency for cereal production. Agronomy Journal, 91, 357-363.

Raupp, J. and Konig, U.J. (1996).

Biodynamic preparations cause opposite yield effects depending upon yield levels.

Biological Agriculture and Horticulture, 13, 175-188.

Riverra-Ferre, M.G. (2008). The Future of Agriculture. EMBO Reports, 9, 1061-1066.

Robertson, G.P. Paul, E.A. and Harwood, R.R. (2000). Greenhouse gases in intensive agriculture. Science, 289, 1922-1925.

Ryan, M. H., Derrick, J. W. and Dann, P. R. (2004). Grain mineral concentrations and yield of wheat grown under organic and conventional management. Journal of the Science of Food and Agriculture, 84, 207-216.

Smil, V. (2001). Enriching the Earth.

Cambridge, MIT Press.

Smith, R.G., Menalled, F.D. and Robertson, G.P. (2007) Temporal yield variability under conventional and alternative management systems. Agronomy Journal, 99, 1629-1634.

Smolik, J.D., Dobbs, T.L. and Rickerl, D.H. (1995). The relative sustainability of alternative, conventional, and reduced-till farming systems. American Journal of Alternative Agriculture, 10, 25-35.

Soil Association. (2009). Soil Association organic standards for producers. Revision 16, January 2009. Soil Association, Bristol.

Stockdale, E.A., Shepherd, M.A., Fortune, S. and Cuttle, S.P. (2002). Soil fertility in organic farming systems - fundamentally different? Soil Use & Management, 18 (Supplement), 301-308.

Stonehouse, D.P. (1991).The economics of tillage for large-scale mechanised farms. Soil and Tillage Research, 20, 333-351.

Stoppler, H. Kolsch, E. and Vogtmann, H. (1989). Impact of wheat breeding in an agricultural low input system. Journal of Agronomy and Crop Science, 162, 325-332.

Street, D.J. (1990). Fisher’s contributions to agricultural statistics. Biometrics, 46, 937945.

Trewavas, A. (2004). A critical assessment of organic farming-and-food assertions with particular respect to the UK and the potential environmental benefits of no-till agriculture. Crop Protection, 23,757-781.

Vereijken, P. (1986). From conventional to integrated agriculture. Netherlands Journal of Agricultural Science, 34, 387-393.

Walker, D. and Smith, A. (1992).

Evaluation of spring wheat, oat and hulless oat and barley cultivars under an organic production protocol. Adaptation Research Reports, 14, 257-260.

Welsh, J.P., Phillips, L, and Cormack, W.F. (2002). The long term agronomic performance of stockless rotations. In: UK Organic Research 2002. Ed. J. Powell. Proceedings of the COR conference. Aberystwyth, pp 47-50.

Williams, A.G., Audsley, E. and Sandars, D.L. (2006). Energy and environmental burdens of organic and non-organic horticulture and agriculture. Aspects of Applied Biology, 79, 19-23.

Woodward, L. Can organic farming feed the world? Elm Farm Research Centre, 6pp.

Woodward, L. and Meier-Ploeger, A. (1999) “Raindrops on roses and whiskers on kittens”. Consumers’ perceptions of organic food quality. Elm Farm Research Centre, march 1999, 4pp.

Wookey, B. (1987). Rushall – the story of an organic farm. Oxford, Blackwell.

Acknowledgements

This paper has been developed from ‘K.W.T. Goulding, A.J. Trewavas and K.E. Giller 2009, Can organic farming feed the world? A contribution to the debate on the ability of organic farming systems to provide sustainable supplies of food, International Fertiliser Society, Proceedings No. 663, 28 pp’. Rothamsted Research is an institute of the UK Biotechnology and Biological Sciences Research Council.

39

6/4/11

12:49

Page 1

economic & social

Organic agriculture: The farming system fit for the 21st century Isobel Tomlinson Policy and campaigns officer, Soil Association, South Plaza, Marlborough Street, Bristol BS1 3NX itomlinson@soilassociation.org

Summary The approaching ‘perfect storm’ of climate change, resource depletion, food insecurity and population growth, in addition to continuing environmental degradation and biodiversity loss, is forcing us all to think again about how we produce and consume food. This paper argues that organic, or agroecological, farming systems, combined with a necessary shift in our diets, offer solutions to many of these critical environmental, social and economic challenges facing our current food and farming system. It provides evidence to support the widely recognised biodiversity and other environmental benefits of organic agriculture, the contribution it can make to mitigating climate change and the impact it can have on achieving food security whilst ensuring a more healthy diet.

Key words: organic farming, agro-ecology, food security, diet.will be added to the global population before its growth levels off later in this century.

Glossary

designing human settlements and

relationships found in natural

Permaculture is an approach to

agricultural systems that mimic the

ecologies.

Abbreviations GHG, greenhouse gas; Introduction The approaching ‘perfect storm’ of climate change, resource depletion, food insecurity and population growth, in addition to continuing environmental degradation and biodiversity loss, is forcing us all to think again about how we produce and consume food.

The current dominant system of intensive, monoculture agriculture has only been made possible through the use of high levels of artificial fertilisers and pesticides, inputs which will not be sustainable into the future given the greenhouse gas emissions (GHG) from their manufacture and use (Scialabba and Muller-Lindenlauf 2010), as well as predictions of future resource shortages, as exemplified by peak oil. Neither is our current food system sustainable, as it delivers a diet high in processed food, meat and diary products to the developed world, and increasingly to the developing world. With concern over the nutrition transition in poorer countries (Lopez 2006) and recognition of the necessity for a substantial worldwide diet change, away from animal products (UNEP 2010) due to the climate impact of livestock products, and the negative effects on ill

health, a radical change in both how we farm and what we eat are now needed.

Organic agriculture is based on agroecology - ‘the science of applying ecological concepts and principles to the design and management of sustainable food systems’ (Gliessman 2007:369). At the core of organic production is a correctly designed and implemented crop rotation.

This provides sufficient crop nutrients, minimises their losses and provides nitrogen through leguminous crops (as well as the use of animal manures). It is also designed to reduce weeds, pests,and diseases and is used tomaintain the soil structure and organic matter content, as well as to provide a profitable output of organic cash crops and livestock. Thus, the use of artificial fertilisers and pesticides is avoided (Soil Association 2008).

In this paper it will be argued that organic, or agroecological farming systems, combined with a necessary shift in our diets, offer solutions to many of the critical environmental, social and economic challenges facing our current food and farming system.

WORLD AGRICULTURE

39

40

6/4/11

12:50

Page 1

economic & social The biodiversity and environmental benefits of organic agriculture

O

ver the last 50 years in the UK there has been a steep decline in wildlife in the countryside.

Research, much of it Government funded, has identified that agricultural intensification led to these declines (Defra, 2009). Organic agricultural systems however, have the ability to reverse this trend. There is now scientific evidence to show the biodiversity and wider environmental benefits of organic farming systems compared to conventional systems (Fuller, Norton, Feber et al. 2005; Hole, Perkins, Wilson, et al. 2005). In 2005, a review of 66 published studies that compared organic and nonorganic farming systems, concluded that on average, wildlife is 50% more abundant on organic farms and there are 30% more species than on nonorganic farms (Bengtesson, Anhstrom, Weilbull 2005).

The UK Government has recognised that organic food and farming offer real benefits to the environment: in their ‘The Action Plan to develop organic food and farming in England’ (Defra 2002) it is stated that “Government financial support for organic farming is justified by the environmental public good which organic farming delivers, which extend

to society as a whole and not just to the minority of consumers who choose to purchase organic food.” Indeed, organic farmers are now financially rewarded for the environmental benefits of organic systems through the Organic Entry Level Scheme. A 2003 study by Defra (Shepherd, Pearce, Cormack et al. 2003) found that organic farming systems had benefits over conventional farming systems according to several environmental indicators, including greater biodiversity, lower environmental pollution from pesticides, greater energy efficiency and control of wastes.

The potential of organic agriculture to mitigate climate change There is now scientific consensus that urgent cuts in the amount of GHG emissions are needed in order to avoid dangerous changes in global temperature. In the UK, research has shown that once agriculture related land use change is factored into the accounts, food and farming represents at least 30% of the UK’s consumptionrelated GHG emissions (Audsley, Brander, Chatterton et al. 2009).

A significant contribution to the potential of organic farming systems to mitigate climate change comes from the carbon sequestration in soils.

Several field studies have shown the

positive effect of organic farming practice on soil carbon pools (Kustermann, Kainz, and Hulsbergen 2008; Fliessbach, Oberholzer, Gunst et al. 2007;Pimental, Hepperly, Hanson et al. 2005) and on the basis of evidence so far available, a recent review of 39 comparative studies of soil carbon levels found that organic arable farming practices produce 28% higher soil carbon concentrations than nonorganic farming in Northern Europe, and 20% for all countries studied (Azeez 2009).

Current intensive livestock systems in Europe are reliant on imported soy for animal feed which is helping to drive the destruction of South American rainforests. In the Amazon in the last decade, soybean cultivation, as well as intensive cattle grazing, have been the dominant drivers of land clearing.

Between 1990 and 2006 the area used for soybean cultivation quadrupled (Zaks, Barford, Ramankutty et al.

2009). This process is having a negative impact on biodiversity, but is also releasing GHGs and further contributing to climate change (FoE 2010). A shift away from such systems to grass-based systems avoids this.

Another potential contribution comes from the careful management of nutrients and thus the possibility of reductions of N2O emissions from soils. Artificial mineral fertilisers that currently cause direct N2O in the range of 10% of agricultural GHG Munnar, India

40 WORLD AGRICULTURE

41

6/4/11

12:50

Page 1

economic & social emissions are not used in organic systems, whilst catch and cover crops extract plant-available nitrogen unused by the preceding crops and retain it in the system. Therefore, they further reduce the level of reactive nitrogen in the topsoil, which is the main driving factor for N2O emissions.

The share of reactive nitrogen that is emitted as N2O depends on a broad range of soil and weather conditions and management practices.

Comparisons between soils receiving manure versus mineral fertilisers found higher N2O emissions after manure application compared to mineral fertiliser applications, but not for all soil types. One study from Brittany found no significant differences between mineral and organic fertilisation (Scialabba and MullerLindenlauf 2010).

Organic agriculture and food security The issue of ensuring food security in the face of climate change, a growing population and future resource scarcity has become a global political concern.

Whilst the focus of political debate has focused on increasing production as the solution to feeding the world, we would do well to remember the words of Amartya Sen (1981:1) that “starvation is the characteristic of some people not having enough food to eat. It is not the characteristic of there being not enough food to eat.

While the latter can be a cause of the former, it is but one of many possible causes”. Thus, solutions to food security need to rest, not only on agricultural production; but also access (for example what can be afforded) and the ability of the individual to benefit adequately from the nutrients provided (Barrett 2010).

In the developing world, where the majority of the future population increase is expected to occur, evidence exists that “organic agricultural systems achieve equal or even higher yields, as compared to the current conventional practices” (Scialabba and Muller-Lindenlauf 2010:158). An analysis of 286 projects covering 37 million hectares in 57 countries found that when sustainable agricultural practices covering a variety of systems

and crops were adopted, average crop yields increased by 79% (Pretty, Noble, Bossio et al. 2005). A study by Badgeley, Moghtader, Quintero et al.

(2007) found that the average yield ratio (organic: non-organic) was >1 in the developing world. A survey from the United Nations of 114 projects in 24 African countries found that yields had more than doubled where organic, or near organic practices had been used (UNEP-UNCTAD 2008). It also found that organic farming increased access to food through the production and selling of food surpluses at local markets which meant that farmers had higher incomes and increased purchasing power, and that it allowed new and different groups in the community to get involved in agricultural production and trade. These groups had previously been excluded for financial or cultural reasons.

In the context of the developed world, the University of Reading carried out a study into what food could be produced if all of England and Wales was farmed organically (Jones & Crane 2009). They concluded that beef production could go up 68% and lamb production up 55%. The output of fruit and vegetables would stay about the same whilst chicken, egg and pork production would fall to roughly a quarter of current levels because of an end to intensive farming systems, which organic standards do not permit. Dairy production would fall by around 30 to 40%. The amount of wheat and barley produced would drop by around 30%. However, because we would be feeding far less grain to animals, more than half of the world’s crops are currently used to feed animals (UNEP 2010), we could have as much wheat and barley for human consumption under an organic system.

The necessity of changing diets The implication of this research is that organic farming practices in the UK could produce sufficient yields to feed the UK population, but that our diet would need to change significantly, towards one that is healthier and more

sustainable. This would include; an overall cut in dairy consumption, with dairy products to be sourced from grass-fed cows from extensive farming systems; more cereals and root crops and more seasonal fruit and vegetables; and less meat overall, but more grass-fed beef and lamb.

Globally, claims are being made of the need to vastly increase food production by 70% by 2050 (FAO 2006) based on projections of further increases in meat and dairy consumption in the developing world, as has been the recent trend.

However, there are widespread concerns about the health impacts that the structural changes in diet have already had in the developed world, and that are increasingly occurring in the developing world.

Such diets are a leading cause of cardiovascular disease, some cancers and Type 2 diabetes (Friel, Dangour, Garnett 2009). Diet-related heart disease and stroke have already taken over as the two leading causes of death in low and middle income countries (Lopez 2006).

Rather than basing policy for food security on the continuation of business-as-usual trajectories, there urgently needs to be a shift in policy attention to considering how a healthy, sustainable diet would be best delivered. A recent study explored the feasibility of feeding 9 billion people in 2050 under different diet scenarios and agricultural systems and found that for a ‘western high meat diet’ to be ‘probably feasible’ ‘would require a combination of massive land use change, intensive livestock production systems and intensive use of the arable land’ (Erb, Haber, Krausmann et al.

2009: 23).

This would have negative impacts for animal welfare and lead to further destruction of natural habitats.

Significantly, the report provides evidence ‘that organic agriculture can probably feed the world population of 9.2 billion in 2050, if relatively modest diets are adopted, where a low level of inequality in food distribution is required to avoid malnutrition’ (Erb, Haber, Krausmann et al. 2009: 29).

WORLD AGRICULTURE

41

42

6/4/11

12:51

Page 1

economic & social Conclusions Current intensive models of farming will not be viable in the future given the challenges of diet related ill health, environmental degradation, resource-use constraints and the need to mitigate climate change. There is increasing support from international scientists for the view that agroecological methods, such as organic farming, offer the best way forward to feeding the world (UNEP-UNCTAD 2008, OHCHR 2010).

Perhaps most significantly, the International Assessment of Agricultural Knowledge Science and Technology for Development (IAASTD 2008) conducted by over 400 scientists concluded that ‘increased attention needs to be directed towards new and successful existing approaches to maintain and restore soil fertility and to maintain sustainable production through practices such as low input resourceconserving technologies based onan understanding of agroecology and soil science (e.g. agroforestry, conservation agriculture, organic agriculture and permaculture).’

References

Audsley, E., Brander, M., Chatterton, J., Murphy-Bokern, D., Webster, C. & Williams, A. (2009) How low can we go?

An assessment of greenhouse gas emissions from the UK food system and the scope for to reduction them by 2050.

How low can we go? World Wide Fund for Nature - UK. No issue or volume number?

Azeez, G. (2009) Soil Carbon and organic farming. A review of the evidence of agriculture’s potential to combat climate change. (Available at http://www.soilassociation.org/Whyorga nic/Climatefriendlyfoodandfarming/Soilc arbon/tabid/574/Default.aspx).

Badgeley, C., Moghtader, J., Quintero, E., Zakem, E., Chappell, M.J., AvilesVazquez, K., Samulon, A. & Perfecto, I. (2007) Organic agriculture and the global food supply, Renewable Agriculture and Food Systems, 22 (2), 86-108.

Barrett, C. (2010) ‘Measuring Food Insecurity’, Science, 327, 825–828.

Bengtesson, J., Anhstrom, J. & Weilbull, A. (2005) The effects of organic agriculture on biodiversity and abundance: a meta-analysis, Journal of Applied Ecology, 42, 261-269.

Defra (2002) The Action Plan to develop organic food and farming in England. (Available at http://www.defra.gov.uk/foodfarm/grow ing/organic/policy/actionplan/pdf/action plan.pdf) Defra (April 2009) Information note – Farmland birds index: How the farmland birds PSA target was formulated.

(Available at http://www.defra.gov.uk/corporate/cons ult/gaec/info-note-farmlandbirds.pdf).

Erb, K., Haberl, H., Krausmann, F., Lauk., C., Plutzar, C., Steinberger, J., Müller, C., Bondeau., A, Waha, K. & Pollack, G. (2009) ‘Eating the Planet: Feeding and fuelling the world sustainably, fairly and humanely – a scoping study’, Social ecology working paper 116, Vienna, November 2009.

FAO (2006) World Agriculture: Towards 2030/2050. Interim Report. Rome: Food and Agricultural Organization.?

42 WORLD AGRICULTURE

Friel, S., Dangour, A., Garnett, T., Lock, K., Chalabi,Z., Roberts, I., Butler, A., Butler, C., Waage, J., McMichael, A. & Haines, A (2009) Public health benefits of strategies to reduce greenhouse-gas emissions: food and agriculture, Lancet, 2009, 374, 2016–25.

Friends of the Earth (FoE) (2010) Pastures New: A Sustainable Future for Meat and Dairy Farming, July 2010.

Fliessbach A., Oberholzer, H.R. Gunst L. & Mader, P. (2007) Soil Organic matter and biological soil quality indicators after 21 years of organic and conventional farming, Agriculture, Ecosystems and Environment, 118, 273-284.

Fuller, R. J., Norton, L. R., Feber, R. E., Johnson, P. J., Chamberlain, D. E., Joys, A. C., Mathews, F., Stuart, R. C., Townsend, M. C., Manley, M. J., Wolfe, M. S., Macdonald, D. W. & Firbank, L. G. (2005) Benefits of organic farming to biodiversity vary among taxa, Biological Letters, Published online.

Gliessman, S.R. (2007) Agroecology: Ecological Processes in Sustainable Agriculture. Boca Raton, Florida: CRC Press.

Hole, D. G., Perkins, A. J., Wilson, J. D., Alexander, I. H., Grice, P. V. & Evans, A. D. (2005) ‘Does organic farming benefit biodiversity? Biological Conservation, 122, 113-130.

International Assessment of Agricultural Knowledge Science and Technology for Development (IAASTD) (2008) Agriculture at the Crossroads: Towards Multifunctional Agriculture for Social, Environmental and Economic Sustainability. (Available at http://www.agassessment.org/docs/1050 5_Multi.pdf).

Jones, P. & Crane, R. (2009) England and Wales under organic agriculture: how much food could be produced? CAS Report 18, Centre for Agricultural Strategy, University of Reading, June 2009.

Kustermann, B., Kainz, M. & Hulsbergen, K. J. (2008) Modelling carbon cycles and estimation of greenhouse gas emissions from organic and conventional

farming systems. Renewable Agriculture and Food Systems, 23, 38-52.

Lopez A (Ed) (2006), Global Burden of Disease and Risk Factors, OUP/The World Bank.

Pimental D., Hepperly P., Hanson, J., Douds D. & Seidel, R. (2005) Environmental, energetic and economic comparison of organic and conventional farming systems. Bioscience, 55: 573-582.

Pretty, J., Noble, A., Bossio, D., Dixon, J., Hine, R., Penning de Vries, F. & Morrison, J (2005) Recource-conserving agriculture increases yields in developing countries.

Environmental Science and Technology, 40(4), 1114-1119.

United Nations, Office for the High Commissioner on Human Rights (OHCHR, 2010) Press release Brussels (22 June 2010) “Right to Food: “Agroecology outperforms large-scale industrial farming for global food security,” says UN expert.” (Available at http://www.ohchr.org/SP/NewsEvents/Pa ges/DisplayNews.aspx?NewsID=10178&La ngID=E).

Scialabbe, N., EH & Muller-Lindenlauf, M. (2010) Organic agriculture and climate change, Renewable Agriculture and Food Systems, 25 (2) 158-169.

Shepherd, M., Pearce, B., Cormack, B., Philipp, .L, Cuttle, S., Bhogal, A., Costigan, P. & Unwin, R. (2003) An assessment of the environmental impacts of organic farming: A review for Defra-funded project OF0405.

Soil Association (2008) The key elements of organic farming.

UNEP (2010) Assessing the Environmental Impacts of Consumption and Production: Priority Products and Materials. (Available at http://www.unep.org/resourcepanel/doc uments/pdf/PriorityProductsAndMaterial s_Report_Full.pdf).

Zaks, D., Barford, C., Ramankutty, N. & Foley, J (2009) Producer and consumer responsibility for greenhouse gas emissions from agricultural production – a perspective from the Brazilian Amazon, Environmental Research Letters, 4, 1 -12.

43

6/4/11

12:51

Page 1

economic & social

Integrated farm management; reducing impact of agriculture and maintaining output – the example of LEAF in the UK Caroline Drummond Chief Executive, LEAF, Stoneleigh Park, Coventry CV8 2LG caroline.drummond@leafuk.org

Summary To address the challenges and choices for global sustainability, farming systems need to be supportive of traditional methods and encourage the development and adoption of new technologies. There will need to be a range of farming systems that can be adapted to specific areas. Furthermore, a collaborative approach is necessary, with farmers working together across landscapes and catchments. LEAF has worked with farmers in the UK, Europe and across the globe to encourage the development and promotion of Integrated Farm Management. LEAF has delivered change in a proactive, engaging and empowering way by involving the whole food chain, including farmers, environmentalists, retailers and consumers.

Key words: Integrated Farm Management

Glossary Stale seedbed: created by preparing a field for sowing or planting and then leaving for several weeks for weeds to germinate. The emerged weeds are killed before sowing or planting.

IFS Integrated Farming System Development Abbreviations IOBC; International Organisation for EISA; European Initiative for the CCRI; Countryside and Community Biological Control Sustainable Development in Research Institute, University of LEAF; Linking Environment And Agriculture Gloucester Farming FOFP Focus on Farming Practice Defra; Department for Environment LIFE; Low Input Farming System Global GAP; Global Good Food and Rural Affairs RSPB; Royal Society for the Agricultural Practice DFID; Department for International Protection of Birds IFM; Integrated Farm Management

Introduction There is increasing pressure on the natural environment and resources of the world, so it is essential that farming systems are developed that have lower impact on the natural environment, but are also highly productive, to meet the needs of a growing population. Land, water, biodiversity and natural habitats are under pressure from competing events. By ensuring that political and consumer decisions incorporate the full value of environmental goods and services and by reducing the rate of loss of biodiversity husbandry contributes substantially towards achieving sustainable development, as described by the World Commission on Environment and Developments (Brundtland 1987).

The options for food production range from low intensity, low output, extensive farming to intensive highly productive systems. While no single system will deliver the ultimate model, IFM strives to balance economic

viability, environmental sensitivity and social gain to provide food security (FAO 1998). IFM is built on the principles of Integrated Pest Management (IPM), a concept developed in the 1950s (IOBC 2011). It has been developed as a workable framework for farmers to balance day to day challenges in a practical, realistic and achievable way, across their farm business. In Europe, EISA is a network of organisations promoting and developing IFM, which includes LEAF in the UK. LEAF was set up in 1991 to develop and promote IFM and to encourage a better public understanding of, and engagement in, farming and the countryside. Since then, LEAF has been developing a whole farm approach to IFM through a range of methods, including technical management, demonstration farms, developing market opportunity and political influence. This article describes how LEAF operates to deliver improvements to the farmed environment and in food.

WORLD AGRICULTURE

43

44

6/4/11

12:52

Page 1

economic & social What is Integrated Farm Management (IFM)?

I

FM is a whole farm approach that combines the best of traditional methods with beneficial modern technologies, to achieve high productivity with a low environmental impact. (LEAF 2008).

The temptation, in problem solving of farming, is to pursue singly issues such as pollution, water security, carbon footprint, local production, and pesticides. Individual approaches, however, do not resolve the interactions. An integrated approach has the potential to be forward looking and provide effective solutions for more sustainable farming, yet be flexible enough to meet changing priorities and address immediate consumer and political demands.

IFM (Fig. 1) provides a framework within which farmers can adopt solutions that yield more efficient and profitable production and which is socially acceptable as well as environmentally responsible. It integrates beneficial natural processes into modern best farming practices, using appropriate science and technology, with established techniques. In this way, IFM can deliver a highly productive agriculture with a reduced environmental impact.

The LEAF approach combines economic, environmental, social and welfare issues with management practices across the whole farm in a balanced way.

Figure 2: Average change (%) in quantity and use as a comparison of inputs in IFM and conventional production systems for arable farming (IACPA 1995)

Figure 3: Change in Gross Margin (%). Comparison of margins in farming systems. IFS refers to the farming system, 1-6 and LIFE refers to Low Input Farming System (IACPA 1995)

The benefits of Integrated Farm Management Research (IACPA, 1995) has shown maintenance of profit through the adoption of IFM, mainly owing to lower input costs (Figure 2) with

reductions of 40% in crop protection products, 15% in fertiliser use and 10% in operating costs, resulting in a 2% (-20% to +15%) increase in gross margin above conventional production (Figure 3). The wide variation is due to the broad diversity of soil types and topography. The results showed that profitability increases in the IFM system as grain prices fall (Figure 4).

Subsequent to this analysis there have been significant price rises for fertilizer and fuel and increasingly

£120

£100

£80

Price per tonne

Figure 1: Integrated processes for IFM as prescribed by LEAF. Doing the right thing, the right way, for the right reasons.

44 WORLD AGRICULTURE

Figure 4: Impact of change in grain price in integrated farming systems compared with conventional systems (% change compared with conventional 100%) (IACPA 1995)

45

6/4/11

12:53

Page 1

economic & social volatile grain prices (Zaman 2010).

Despite this, IFM has delivered increased profitability, environmental benefits and social capital (Mills 2010).

This study provides evidence from LEAF demonstration farms and members that the IFM approach provides reduced inputs and increased profitability (Table 1).

Further work at a LEAF Innovation Centre (Table 2) demonstrated the logic of IFM in delivering key sustainability benefits through the adoption of minimum tillage (Drummond 2005).

These approaches are consistent with environmental responsibility to farming to reduce impact on the local environment by:

Table 1: Potential economic benefits of IFM, based on studies of typical farms

Optimizing /minimizing inputs Encouraging an increase in biodiversity Reducing potential pollution Adherence to waste and energy management standards Improved soil management and maintenance of soil organic matter (See Box 1, Page 46)

Links between biodiversity and agriculture As increasing pressure is placed on food security, there are growing fears of environmental degradation. The importance of the environment, biodiversity and the amenity benefit provided by our agricultural systems is frequently ignored.

People rely on biodiversity in their daily lives, often without realising it, so that it is undervalued. The bacteria and microbes that transform waste into useful products, insects that pollinate crops and flowers, and the biologically rich landscapes that provide enjoyment, are only a few. It has been concluded that IFM is better for biodiversity than conventional farming in mixed or arable systems (Berry et al. 2005).

Table 2: Environmental, economic and social benefits of IFM and the rationale for reduced impacts.

However, a major challenge to widescale implementation of these approaches is the lack of appropriate policy frameworks and governance that align rural and agricultural policies with the protection of biodiversity and ecosystem services.

Without such links, the concern is that the value of integrated natural resource management systems and eco-agriculture innovations will remain marginal in ensuring the long-term

WORLD AGRICULTURE

45

46

6/4/11

12:53

Page 1

economic & social and affordable.

Political influence by talking with policy makers Supporting research, innovation, education, knowledge exchange and communication throughout the food chain.

LEAF provides existing knowledge and sound husbandry updated by application of the results of research and technology. We actively encourage farmers to review their current practices and improve their production systems.

The aim is to provide management tools for farmers in the adoption of IFM.

The LEAF audit

Box 1

viability of biodiversity.

Agriculture has two global trends that threaten biodiversity: intensification and abandonment. The most intensive farm systems result in highly productive monocultures, with low biodiversity. At the other end of the scale are the species rich, traditional farming systems that have shaped the European landscape and created habitats rich in species, yet are not sufficiently productive to meet global food security needs. Through its effects on biodiversity, IFM offers the potential to gain benefits from these extremes.

Making Integrated Farm Management happen LEAF was set up to emphasize the need for practical and achievable methods to farmers, consumers, processors and retailers, through management, demonstration and food assurance. The role and potential of IFM in provision of more sustainable food security has been consolidated by cooperation between growers, environmentalists, consumers and

46 WORLD AGRICULTURE

companies throughout the agriculture and food supply chain. This encourages implementation of sustainable measures through demonstration, communication and farm assurance (IACPA 1995). The emphasis has been on grower involvement by creating added value for collaborating farmers through accrediting produce with environmental benefits.

Attention to detail is an essential part of IFM. Wise and efficient use of resources, smarter approaches to business planning and new technologies all contribute to increasing productivity, whilst still protecting valuable resources. IFM becomes a key to achieving long term food security.

In order to deliver IFM, LEAF focuses on four areas: Technical know-how by developing and promoting sustainable farming systems Demonstration and communication to create a better understanding amongst farmers and consumers Market opportunity by making accredited food chains easily accessible

The LEAF Audit was developed in 1993 with the collaboration of farmers, researchers, environmentalists, the food supply chain and agricultural industries. It is a self-assessment whole farm management system that gives farmers the opportunity to appraise honestly, and improve their farming practices. It enables farmers to set themselves targets for action annually and to compare themselves with other LEAF members. It is based on the Environmental Management Systems approach operating in many other industries (Drummond 2000).

Each year >1000 farmers complete the LEAF Audit, helping them adopt IFM. It has provided the template for other farm assurance standards, including the Red Tractor (Drummond 2000) which has been developed as a food safety standard in the UK. The Audit is updated annually and is well regarded throughout the agricultural industry, by, farmers, retailers, Defra and its agencies and environmental organisations, such as RSPB (fwi 2011).

The Green Box The LEAF Green Box is a scheme, to help farmers assess and monitor the farm environment. It was developed recently by LEAF in association with leading environmental organisations, researchers and members. The Green Box supports farmers in monitoring the wildlife and resource management activities of their farm by providing knowledge and recording sheets. It gives opportunity for farmers to gain a closer involvement with their local communities, encouraging partnerships and exploiting local skills,

47

6/4/11

12:56

Page 1

economic & social to help with monitoring. Using this participatory approach provides a valuable way to develop the scheme, identifying beneficial practices that enhance biodiversity.

Demonstration Farms Among the 2300 farmer members LEAF now has over 100 demonstration farms. These promote IFM, helping other farmers to improve their business and environmental performance. By using working farms, farmers and advisers are able to see what might be adapted to their own systems. Demonstration Farms aim to provide reassurance and act as a source of inspiration for new ideas and technologies, receiving ca 20 000 visitors annually, including farmer groups. They are not open farms and the arranged visits provide an important venue for considering issues of crop health, animal welfare, and environmental performance.

Plate 1: Visitors to a LEAF Demonstration Farm discussing soil management.

In 2000, we set up the LEAF Innovation Centres to work with research establishments, agricultural colleges and universities. Our aim is to build knowledge, based on research for innovative solutions (LEAF 2009), to provide farmers with an insight to new ideas, some of which are yet to be used in practice. This is critical in addressing sustainable farming options in the LEAF Sustainable Innovation Network which brings together farmers, industry and researchers.

Feedback shows that Open Farm Sunday plays an important part in explaining to the general public the important links between food, farming and the environment and over 80% of the visitors agreed that the day was valuable (Figure 6). After visiting a farm, there was a clear shift in the public understanding of these issues from ‘poor’ or ‘good’ to ‘very good’ or ‘excellent’ (LEAF Open Farm Sunday 2010).

Open Farm Sunday; Engaging consumers Research has shown that when children, especially under the age of 11, experience a touch of wildness and learn basic outdoor skills their selfconfidence is increased, encouraging freethinking and environmental awareness. (Louv 2005). This awareness can lead to relevant shopping choices (CGU 2010).

If children gain these memories before the age of 11 the memories are retained for life. That is why Open Farm Sunday is so important to provide children and families a taster of country life.

Market Standards LEAF Marque was developed to provide a quality standard for food produced to IFM standards. It has built on farm assurance schemes, such as Assured Food Standards (http://www.redtractor.org.uk) and Global GAP (http://www.globalgap.org). LEAF Marque is inspected jointly, or independently, with the existing schemes by the certification bodies involved with farm assurance. The standard is developed collaboratively with many organizations, including Waitrose and other retailers, RSPB, Natural England, farmers, The Environment Agency and WWF. It is managed by a technical advisory board and a management committee

Now in its fifth year, Open Farm Sunday encourages farmers to welcome the public on to their farms.

During this time, over 750 000 people have visited over 900 open farms coordinated by LEAF to make farming come alive. LEAF provides resources and workshops for farmers dealing with health and safety. In June 2010 over 420 farmers took part and with the help of some 6 100 people in the industry, welcomed circa 184 000 consumers on to farms on one day.

Of these visitors 36% were under 18 (Figure 5).

2010

18 - 25

Under 18

2008

2009

2007

36 - 50

26 - 35

Figure 5: Age (years) distribution of numbers of farm visitors to Open Farm Sunday between the years 2007 to 2010

How visitors rated their knowledge of farming in general Poor

Plate 2: Demonstrations at Open Farm Sunday provide an opportunity to build trust and understanding among thousands of visitors.

Over 50

Before OFS

Good

Very Good

Excellent

Figure 6: Change in distribution of knowledge of farming, poor to excellent (%) as estimated by all visitors before and after a visit to Open Farm Sunday in 2010

After OFS

WORLD AGRICULTURE

47

48

6/4/11

12:57

Page 1

economic & social and provides a whole farm standard which requires that member producers demonstrate continual improvement in environmental management. (LEAF 2011). LEAF Marque is an accredited scheme to the UKAS EN450011 standard to ensure that consistent inspections and certifications are carried out by multiple certification bodies worldwide. This independence is vital.

The owner or manager of a farm will contact the certification organization for inspection without any guarantee of a favourable outcome.

Ensuring the consistency of LEAF Marque worldwide is paramount. The food chain and consumers can verify product status using the associated LEAF Track’s system. This is a custody and warranty agreement which tracks LEAF Marque produce, composite ingredients and products, giving LEAF the ability to carry out product audits.

This system facilitates trade in LEAF Marque produce within the food chain.

South America and North Africa.

There are three pilot groups in Kenya, where 150 farmer members, some with as little as one-eighth of an acre, are being trained so that they can be certified as farming to LEAF Marque standard (LEAF Annual Review 2008 and 2009).

Trade policy is the driving force for this standard. Recognising the economic and social significance of export horticulture in Africa, in 2010 the DFID challenged (http://www.dfid.gov.uk/Workingwith-DFID/Fundingopportunities/Business/FRICF/) major UK retailers to increase the flow of African produce to Europe, especially from smaller scale producers. It offered to match funds pledged by retailers to invest in efforts for more African produce on shop shelves through grants from the Food Retail Industry Challenge Fund (FRICH).

Waitrose aims to increase sales of African fresh produce in their 241 stores by 10% of, for example, green beans and peas from Kenya and prepared fruit from Ghana, from small scale LEAF Marque accredited farms.

Long term sustainability is attractive, but reducing costs of production is another incentive. Blueskies Ghana Limited gained LEAF Marque certification for 40 farmer suppliers in early 2009, who export prepared tropical fruits to five European countries and process 15 t of pineapples a day at their factory just north of Accra.

“The main benefits are it really helps you produce at lower cost,” explains Ernest Abloh, Head Agronomist, Blueskies, Ghana, who works closely with farmers. “LEAF Marque is exceptional.

You have good recordskeeping and attention to detail, and that helps farmers to use integrated pest and crop management practices that help reduce the use of agrochemical and fertilisers.”

The passion of the African farmers is shared by many UK farmers. IFM and the LEAF Marque enable farmers to continually challenge their processes.

Assurance schemes have been developed in response to the significant challenges facing government, farmers and retailers to feed a growing world population and to help protect precious resources and the environment. A recent study commissioned by Defra reveals that not all schemes are based on the same criteria (Lewis 2010). LEAF Marque is leading the way in the environmental labelling of food. The research evaluated a number of schemes and compared how they help to protect the environment. LEAF Marque scored

Plate 3: Packed spinach showing the LEAF marque logo and the LEAF Tracks reference to enable consumers and retailers to trace the product origin

LEAF Marque is one of the fastest growing food standards. All the nonorganic British fruit and vegetables sold by Waitrose are grown on certified farms. Overall 18% of the UK’s fruit and vegetables are LEAF Marque accredited. However, only about 47% of the products from certified LEAF Marque farms bear the logo in retail stores, owing to mixture along the chain. This is a lost opportunity we wish to change.

The IFM and LEAF Marque approach is now being used by farmers of 17 other countries in Europe, Middle East,

48 WORLD AGRICULTURE

Plate 4: Picking beans for LEAF Marque produce in Kenya

49

6/4/11

12:58

Page 1

economic & social the highest marks across a range of criteria, whereas better known schemes scored significantly less well in some important areas. The report calls for a more consistent approach and highlights the need for environmental labelling to be based on robust, scientific evidence.

Online Encyclopaedia Our knowledge base is developing into an online LEAFipedia to host technical information, practical solutions, and industrial examples. We are also developing podcasts and videos as part of the reference system.

Open Farm Sunday

Conclusions LEAF is developing the IFM model to promote the production of high quality, fairly produced food to enthuse farmers, consumers and retailers. We work with farmers who are passionate about the food they produce and who care for their farm environment and natural resources. Our members are also committed to taking their story into the market place with the of LEAF Marque to demonstrate that the producer has gone ‘the extra mile’ for the environment to provide good quality, affordable food, showing what they do, with events such as Open Farm Sunday.

LEAF works with thousands of farmers in the UK and overseas. As the food chain becomes increasingly complex, we need to help consumers understand the story behind food, the authenticity of production standards, the commitment of the producers and how consumer buying decisions make a difference to how food is grown. There will be stark choices for us to take as individuals and society, with new technologies, engineering innovations and preservation techniques. These will allow us to grow more produce safely and with less impact on the environment. Our strategy of communication and collaboration is fundamental to ensure a co-ordinated and comprehensive approach to sustainable agriculture. Developing more sustainable systems of agriculture will continue to be a priority and LEAF and the adoption of IFM is a key part of making this happen.

References Beddington J (2009) Sustainable Development UK 09 Conference 19 March 2009. www.sdcommission.org.uk/ Berry, P Ogilvy, S and Garnder, S (2005). Integrated farming and biodiversity. ADAS/English Nature. English.

Nature Research Reports no. 634.

Bruntland, G (1987). Our common future: The World Commission on Environment and Development. Oxford, Oxford University Press CGU (2010) Unheard Voices: the case for supporting marginal farmers John Madeley Drummond, C (2000). Environmental management systems in practice: the experiences of LEAF (Linking Environment And Farming) in meeting the needs of farmers, consumers and environmentalists. Aspects of Applied Biology 2000 No. 62pp 165 – 172.

Drummond, C (2005) LEAF Where is the payback IAgM Conference proceedings. Journal of Farm Management, 12 (5) EISA (2009). Integrated Farming Framework. A European Definition and Characterisation of Integrated Farming as Guideline for Sustainable Development of Agriculture in Theory and Practice. EISA. Rue J. B. Vandercammen 10, B-1160 Brussels FAO (1998). The State of Food and

Farming. Economic and Social Development Department, FAO, Rome Foresight Report (2010). The Future of Food and Farming 25th January 2010.

Government Office for Science Fwi (2011). http://www.fwi.co.uk/Articles/2010/12 /23/124900/New-Year-Plans-What-aLEAF-audit-can-do-for-you.htm IACPA (Integrated Arable Crop Production Alliance) (1995). Integrated Farming: Agricultural Research into Practice. MAFF. IGD (2005). Connecting Consumers with Farming and Farm Produce, commissioned by The Sustainable Farming and Food Strategy Implementation Group.

IOBC (2011). <http://www.uibk.ac.at/bipesco/iobc_w prs_2011/> LEAF (2009). LEAF Sustainable Innovation Network Feasibility Study Knowledge systems – past reflection, future direction. LEAF, Stoneleigh Park, Warwick CV8 2 LG LEAF Annual Review (2008 and 2009).

LEAF, Stoneleigh Park, Warwick CV8 2 LG LEAF Audit (2009). LEAF, Stoneleigh Park, Warwick CV8 2 LG LEAF (2005a). Measuring Change Environmental Improvement on Farm over 10 Years, Demonstrated by Analysis of the LEAF Audit Data. LEAF for the

Crop Protection Association.

LEAF (2005b). Speak out CD Rom. LEAF, Stoneleigh Park, Warwick CV8 2 LG LEAF (2011). <http://www.leafuk.org/LEAFmarquecer tification/standard.eb> LEAF Open Farm Sunday (2010).

Successes Shared. LEAF, Stoneleigh Park, Warwick CV8 2 LG Lewis, K, Green, A., Tzilivakis, J. and Warner, D.J. (2010). The contribution of UK farm assurance schemes towards desirable environmental policy outcomes. International Journal of Agricultural Sustainability, 8(4): 237–249.

Louv, R (2005). Last Child in the Woods – saving our children from nature-deficiency disorder. Atlantic Books Mills, J, Lewis, N and Dwyer, J (2010).

The Benefits of LEAF Membership: a qualitative study to understand the added value that LEAF brings to its farmer members. CCRI Report to LEAF. LEAF, Stoneleigh Park, Warwick CV8 2 LG Zaman H, (2010). Food Price Watch World Bank Poverty reduction and equity group, Poverty reduction and economic management network. http://siteresources.worldbank.org/INTPOVERTY/Resources/NutritionalImpact_F oodPriceShocks.pdf

WORLD AGRICULTURE

49

50

6/4/11

13:03

Page 1

book & report reviews

The Foresight Report, The Future of Food and Farming: Challenges and choices for global sustainability Reviewed by Professor Sir John Marsh The Future of Food and Farming: Challenges and choices for future sustainablity, (Foresight Report, London, UK Government, Office for Science. WEB: January, 2011) This is a very good report. It does address the issue of food security in a global context, it looks at the industry as a whole, not just food production on the farm, it recognises that this industry can only be understood within the economic system of which it forms part, it reflects what is the current consensus on some key uncertainties about climate, the prospects for research based increments in productivity and the conventional wisdom on political social issues such as the need to ensure freedom from famine for vulnerable populations and the importance of the non-food outputs of land use. This ensures it will have a powerful influence on the development of policy.

The Report might be criticised for taking too little account of the autonomous adaptation in patterns of behaviour that changing circumstances will bring about over a period of fifty years. This tends to encourage a too precipitate shift from diagnosis to prescription. In a political context this is understandable, it looks defeatist to identify a problem but fail to propose a solution. However, many of the solutions proposed rely on assumptions about the behaviour of other countries and agencies over which the UK government has no control. We have to face the reality that while some of these actions may claim the moral high ground, if others do not act in concert, the impact can be to weaken the UK competitiveness

50

WORLD AGRICULTURE

without having any perceptible impact on the global problem identified.

Several issues identified in the report lead to the following comments: 1. The assumption that the world overall will be richer, does not match the alarm that resource scarcity threatens survival. The conventional economic analysis suggests that prices would rise choking off demand and bringing about a redistribution of income. Those who would have to go without, even to the point of failing to survive, would be those with low relative incomes or entitlements.

Entitlements can arise as a result of family solidarity or through interpersonal transfers via a social security system. This is not a future scenario. Today those with too few entitlements or too low an income already die during famine, are victims of epidemic disease or suffer disproportionately from the vagaries of weather, volcanoes, earthquakes etc.

2. The paper’s analysis that the current rate of growth in population will lead to unsustainable demands on land, water and energy is an important signal that it will not happen. The more refined analysis is central to what sorts of adjustment are feasible and what actions might reduce the number of those who fall below the ‘survival’ level. This analysis looks for example at the pressure on critical inputs that are in limited supply, (e.g. some fertilisers), at the efficiency with which resources are converted into output, (productivity), at changes in the nature of demand resulting from changes in lifestyle and convictions about health, and waste in terms both of pollution and as a potential route for increasing overall efficiency.

3. The scale of action demanded depends upon how various key uncertainties play out. Leading these is the issue of climate change. Global

warming is generally accepted, but the rate of change, the distribution of impacts and the way in which society adapts are much less clear. It is virtually certain that simply projecting recent trends will mislead. Equally uncertain is the impact of changing technology. This has several different aspects, first discoveries in fundamental science, second the application of these within an economic system and third their acceptability to populations. History suggests that a positive attitude is justified but it cannot be taken for granted. An uncertainty that is little discussed is the impact of changes in real wealth distribution on the peace of the world. It is not unrealistic to see emerging tensions between the new economies of the East, the value systems that dominate the Middle East and the interests of the West. We already have localised wars, it would be unrealistic to rule out global conflict.

4. The scope for action depends upon the viability of political judgements that will be challenged by events.

Classical amongst these are the actions taken to deliver such ‘public goods’ as biodiversity, landscapes and clean air and water. For some, these goods have been treated as of absolute value so that human activity must be adapted to accommodate them. For others they are seen as falling into one of two categories, those essential to preserve the basic necessities of life and those that add delight through their aesthetic benefit, through sustaining diverse human communities and through maintaining a clear record of the past. For this group the test will be how many of these benefits society can afford linked to issues about how to deliver them with greatest efficiency.

5. Attempts to deliver food security by a top down approach have little hope of long-term success. The most ‘The

51

8/4/11

13:18

Page 1

report review convincing example would be the UK food rationing programme in the Second World War. However, even here and still more in other countries, rationing systems were partly undermined by â&#x20AC;&#x2DC;black marketsâ&#x20AC;&#x2122;. The approach via regulating prices goes someway to leaving decisions by individuals about what to cut and what to protect. However, long term price controls â&#x20AC;&#x201C; as for example in pre-

1989 Eastern Europe, lead to massive waste and technological stagnation.

More durable results can result from actions that facilitate the discovery and application of new technologies and from changing individual preferences in relation, not only to health, but to what is perceived as good food.

The capacity for change at this level is

substantial as the growth of ethnic food in the UK during the past few decades illustrates. This implies that the goal of government price policy must be limited to remedying market failure, where market prices diverge from the social value of products or resources, and engaging in a dialogue with the population based on their interests and rooted in the best evidence available.

Lichens depend upon a symbiotic relationship with algae for the fixation of atmospheric nitrogen

WORLD AGRICULTURE

51

52

6/4/11

14:33

Page 1

book review

Truth about Organic Foods

by Alex Avery Truth About Organic Foods’ (2006) by Alex Avery. Henderson Communications LLC, Chesterfield. (ISBN-13: 978-0-9788952-0-4).

Available from Jonathon Harrington, Optima Excel, Pen-y-Lan, Tregoed, Brecon, Powys, LD3 0SS, UK. It is not our normal practice to publish more than one review of a book, but this book has been the subject of much controversy, so we considered it right to put forward alternative opinions on the text. Moreover, we are focussing on the "organic" debate in this Issue.

This debate should allow the readers of World Agriculture to reach a considered and valid judgement of the position of “organic” agriculture and “organic” foods in global production.

Ed. At a time of growing concerns about availability and the increasing cost of food in many parts of the world, it is particularly interesting to reflect on Alex Avery’s perspectives in ‘The Truth About Organic Foods’. He sets out, by his own admission, to debunk ‘organic myths’ surrounding organic farming, organic foods and the ‘organic’ movement more generally. Claims and counter-claims are examined rigorously in a comprehensive analysis in reaching his, often brave, conclusions. Commendable efforts have clearly been put into background research in reaching the judgements made. The language used is sometimes robust, from an author who clearly does not suffer organic enthusiasts lightly, and readers are left with the distinct impression of little love lost as Mr Avery sets about demolishing various beliefs (preciously) held by the organic movement. To his credit, however, the author has pursued a careful scientific approach to his study – and the conclusions reached are clearly explained throughout. The text is peppered

52

WORLD AGRICULTURE

with quotations; case studies; separate box comments with various figures and photographs as illustrations, which can enliven and provide much interest.

From a somewhat critical start Mr Avery becomes slightly more generous later in the book recognising (in his own words) that ‘many organic farmers are excellent farmers and get good yields from their crops’ (p.162).

He also says (p.148) ‘Organic foods can be better (than conventional).

There is no question about that. In fact, my wife and I […] regularly buy organic bread from our local food supermarket. […] Why? Because it is simply the best bread in the store’ – included in the aptly named Chapter 8 ‘If It’s Better, Buy It!’ However, the author rightly highlights, in protecting consumers right to buy organic food, that it remains particularly important to challenge inaccurate promotional statements which can be proved to be scientifically incorrect. The author rightly asks important questions about many of the organic industry claims.

Most readers would, I suspect, enjoy the early part of the book on how the organic movement got started – which makes for a highly informative first chapter. For me, as an agricultural scientist who has worked on both organic and conventional farms, the gem remains Chapter 9 of ‘A Few Bushels Shy’. It provides a well researched and clear account of the poorer field performance of organic crops. Anyone who has farmed organically will understand the need to build fertility through legumerotations and organic manure-use to secure reasonable productivity on most soils, and then recognise that the crop output will invariably be lower, relative to a comparable conventional crop receiving fertiliser and agrochemical inputs. Comparisons are detailed, in the book, of where organic crops yield 10% to 80% lower than conventional production systems. I would add the ‘Organic Farming Versus Wildlife Habitat’ chapter to my choice, where coverage of the socalled Bichel Committee Report (p.208) is well worth inclusion (in my view). The Bichel study, into whether Denmark could feed itself organically in the future, concluded that human

food production could drop by around 47% - and potato production by as much as a possible 80% - in an organic Denmark. Not something anyone would wish to contemplate seriously in times of food security concerns. As others have also concluded, it is very unlikely that organic farming could feed the world in the face of our ever-growing population demand.

Comments by the author on disrupting the ‘balance of nature’ in conventional farming (Chapter 10) are less persuasive. There are well documented examples of where the dynamic equilibrium has been seriously destabilised, especially with pest and disease problems, which have been exacerbated and made more difficult to control in certain crops by some modern agricultural practices – through pesticide treatments in particular. Hence the increasing enthusiasm for greater integrated pest management (IPM) approaches in crop protection more generally. An approach persuasively promoted in the UK by LEAF supporters. Not everybody would agree, either, with some of the comments in the chapter on ‘Dismantling Capitalism…’ where the author draws parallels between the organic movement and communist ideals, that some may perhaps consider rather intemperate.

Mr Avery’s wrath is mostly reserved, however, for negative ‘organic’ attitudes and comments about agricultural biotechnology. He concludes that this extreme intolerance towards biotechnology adoption in organic agriculture must be grounded in a fear of competition – as a major threat to the future of organics. He may well be right, in this regard, and the cases clearly presented in support of his arguments are highly persuasive. The rejection of modern biotechnology is difficult to understand, otherwise, in circumstances where clear environmental and productivity benefits can be demonstrated.

The many excellent quotations in the book, for one side or the other in this on-going polarised debate, probably say it all. He quotes, for example, Lord John Krebs during his time as Chairman of the UK government’s

53

6/4/11

14:34

Page 1

book & report reviews Chairman of the UK government’s Food Standards Agency who reportedly said ‘organic food is an important addition to consumer choice – but no independent scientific evaluation has ever shown that it is any healthier. Organic consumers are not getting value for money, in my opinion, if they think they are buying food with any extra nutritional quality or extra safety.’ It still has to be recognised, of course, that organic food production remains a significant part of the food industry, and a growing sector in some countries, popular with very many consumers.

The last word should perhaps be left to the late Norman Borlaug, the eminent Nobel Laureate and ‘father of the Green Revolution’, who is reported to have said ‘if people want to believe that organic food has better nutritive value, it’s up to them to make that foolish decision. If consumers really believe that it’s better from the point of view of their health, God bless them. Let them buy it. Let them pay a bit more. It’s a free society.’ Mr Avery concludes, quite appropriately, that the organic community has the right to continue to farm and market organic products to all those customers who wish to enjoy organic foods, and that it should remain ‘ live and let live ’.

He goes on to say ‘there is room for organic farmers, conventional and biotech farmers to farm peaceably on this planet’ – and many will feel the same. An interesting read – and, as it should be with this continuing debate, entertaining and suitably provocative Professor Paul Davies, in parts.

Royal Agricultural College Alex Avery's controversial The Truth About Organic Foods begins by reminding us that the roots of organic agriculture are deeply embedded in occult and Romantic mysticism. Rudolf Steiner ("When I eat roots, their minerals go up into my head. When I eat salad greens, their forces go to my chest, lungs and heart-not their fats, but the forces from their fats.") and J.I. Rodale ("Old farmers who remember how their grandfathers grew crops...will tell you of the fine crops and very little plant and animal disease and insect depredation.") are the bestknown organic pioneers of the 20th century, but modern consumers have driven the double-digit growth of the industry in recent years with more

pragmatic concerns about chemical pesticides on the conventional farm and preservatives in processed food.

Today's organic industry attracts its chemophobic clientele with bucolic images of fresh, nutritious foods devoid of chemicals, grown on small farms in an environmentally sustainable manner by local organic farmers. We are whisked back to a gentler time when life was good and foods were entirely natural, with no chemicals, no pesticides, no GMOs, no massive corporate farms and no multinational retailers.

After this quick history of the organic philosophy, Avery proceeds to attack the popular beliefs behind its commercial success. Consumers buy organic foods because they believe them to be healthier, tastier, lacking in pesticides, and better for the environment and for local family farms. All of these may be valid and honourable reasons for choosing a particular food and lifestyle, but according to Avery, they do not apply to the current organic industry. Avery challenges the common claims in chapter after chapter. Is organic food more nutritious? Is organic healthier?

Is organic safer? Does organic means pesticide free? Are approved organic pesticides benign? Does organic food taste better? Does buying organic support local family farmers? Is organic farming better for the environment?

Avery documents (and cites comprehensively) the independent scientific studies addressing these questions and concludes there is no scientifically credible evidence to support organic foods or farms being categorically superior to conventional in any respect. Organic does not mean 'no pesticides', because organic farming does allow certain 'natural' pesticides. And 'natural' does not mean 'healthy' or even 'benign', as those natural organic pesticides can be very hazardous, even more so than the proscribed synthetic chemicals. Even if one discounts Avery due to his personal bias, it is hard not to accept the apparent consensus of the scientific studies showing, for example, no categorical or meaningful nutritional differences between organic and regular foods.

The book's final chapter is devoted to biotech. Avery focuses on a curious paradox: some biotech crops are demonstrably beneficial for the environment, including those offering improved disease or pest resistance

with reduced chemical inputs, or better weed control without resorting to tillage, a major cause of soil erosion and practiced most intensively by organic farmers. Biotech farmers have documented benefits to sustainable production, and many organic farmers want to obtain them also. Clearly, appropriate applications of biotech help fulfill the organic dream of environmentally sustainable agricultural systems, and biotech would welcome organic farmers. But instead of embracing and encouraging biotech, organic leaders have expressed their unrequited enmity for biotech by forbidding organic farmers from growing biotech crops and calling for a ban on the new technology altogether. They have even imposed zero tolerance for 'contamination', allowing not a single biotech pollen grain in organic crops.

This intolerance is especially illogical considering other forbidden 'contaminants', including synthetic pesticides, are permitted under a reasonable 5% threshold. Perhaps organic leaders thought proscribing biotech would dissuade farmers from adopting the new technology, but with worldwide biotech crops now well established organic farmers are painted into a non-sustainable corner by the intemperate decisions of their own leaders.

So why did the leaders choose this impracticable zero standard for biotech when even known toxins like arsenic are permitted at low levels?

The usual reply is the organic philosophical opposition to human intervention in nature's realm, an intervention upon which biotech is founded. But this explanation is unsatisfactory; the organic philosophy has no such aversion to other unnatural human interventions in breeding, such as the use of irradiation or chemical mutagenesis to create crops grown by organic and other farmers.

Avery offers a more sanguine explanation: the adamant opposition to biotech is because of competition.

"Biotechnology," he says, "offers a more cost-effective way to achieve lower pesticide use and more ecofriendly farming systems ... biotechnology represents a direct threat to organic agriculture's current monopoly on eco-conscious Dr Alan McHughen consumers."

BSc, Dphil WORLD AGRICULTURE 53

54

6/4/11

14:34

Page 1

instructions

World Agriculture: problems and potential Instruction to contributors

T

his international Journal publishes articles based upon scientifically derived evidence that address problems and issues confronting world agriculture and food supplies. All will be subject to review by two or more scrutineers before acceptance. Authors are encouraged to take a critical approach to world-wide issues and to advance new concepts. Those wishing to submit an unsolicited article should in the first instance send a short summary of their intended paper in English by electronic mail to the Editor. The journal will publish suitable articles on agriculture and horticulture and their climatic, ecological, economic and social interactions.

Relevant aspects of forestry and fisheries as well as food storage and distribution will also be acceptable.

The Journal is not available for communication of previously unpublished experimental work, although original deductions from existing information are welcome.

Statements must be based on sound scientifically derived evidence and all arguments must be rational and logically derived. Typical articles will be between 1 000 – 3 000 words, with photographs, and figures, line drawings and tables, where relevant.

Articles outside these lengths may be acceptable, if the length can be justified.

Articles that pose questions and raise issues for which answers are needed will be accepted if they meet the necessary criteria. Such questions may for example, describe an economic or husbandry problem in a developing country or ocean, resulting from climate change or some unintended consequence of policy, for which no clear solution is at hand.

World Agriculture will produce one volume each year with Issue numbers 1, 2, 3 and 4 occurring within each volume. Page numbers will run consecutively throughout each volume from page one onwards.

54

WORLD AGRICULTURE

Sections The Journal has three main Sections: (1) Scientific, (2) Economic & Social, and (3) Comment & Opinion. It also accepts Letters to the Editor and includes Book Reviews and Editorials.

Scientific, Economic and Social Statements of fact in the first two Sections must be based on evidence from peer-reviewed publications which must be fully referenced.

Comment and Opinion Submissions must be based on considerable experience and be logically argued. Articles that pose questions and raise issues for which answers are needed will be accepted if they meet the necessary criteria following rigorous examination. Such questions may for example, describe an economic or husbandry problem in a developing country or ocean, resulting from climate change or some unintended consequence of policy, for which no clear solution is at hand.

References are not essential, although they should be used to justify statements where appropriate.

Layout and typing instructions SI units and the English language must be used, the spelling being generally that of the Concise Oxford Dictionary, 9th Ed, so that words such as fertilizer should use ‘ise’ rather than the American ‘ize’ spelling. Times New Roman 12 point font should be justified for normal text and Arial should be used for headings.

Standard abbreviations (e.g. Fig. and Figs) are acceptable, but specialist abbreviations and terms should be defined in a short Glossary, immediately beneath the Summary.

Additionally, key words should also be included beneath the summary. Full stops are not used in commonly accepted abbreviations (e.g. USA, UK) and should not be used when an abbreviated word ends with the same

letter as the complete word (e.g., Florida as FA and cultivar as cv.). Latin terms such as circa should be italicised and ca is the abbreviation.

Commercial chemicals should be referred to by their approved common names, but where a proprietary name is relevant and unavoidable it should be used with a capital initial and the manufacturer named at the first mention. Concentrations and rates of application should be clearly expressed and unambiguous, using, for example, mg/litre, or mg/L, mg/kg (not ppm).

Dates should be expressed as day, month, year, as for example, 18th May 2010.

Currency references should use the standard international abbreviations, eg USD, EUR and GBP for US$, ? and £ respectively. Wherever possible financial details should be quoted in these currencies, although where this is not possible a standard list of abbreviations is available at <http://www.forex-rates.biz/currencyabbreviations.htm> which was accessed in March 2011.

The full Latin name of an organism should be given at the first mention, e.g. Heterodera avenae; an abbreviated name of the organism may be used for subsequent mentions, e.g. H. avenae.

Always use numerals for specific units of measurement (e.g. 14 m, 2 d, 3 wk). For other quantities up to and including nine, spell out in full (e.g. four plots, two experiments, nine larvae). Use numerals in all instances for ten or over (e.g. 20 fields).

Large numbers should be separated by spaces every 000, rather than by use of a comma, e.g., 10 000.

Hyphens should be avoided if possible, for example use ‘cooperate’ rather than co-operate’.

55

6/4/11

14:35

Page 1

instructions Sequence of headings Each paper should commence with a short concise, accurate and informative Summary, normally of approximately 250 words, that includes the issues posed, the subject covered and the conclusions drawn.

The Introduction should set out the background to the subject. This is to be followed by the main body of the article in sections each of which is headed by terms defined by the nature of the paper, for example: Background, Review of evidence, the Present situation, Problems to be confronted and Resolution.

The paper should conclude with a Discussion and/or Conclusions section and finally References. Layout of headings should follow the guidance below: Title, bold 16 point Author name Affiliation Main headings central bold Arial 14 point font Secondary headings: left justified, bold Arial 12 point font Tertiary level: left justified, Arial 12 point font Quaternary (if necessary) left justified, Arial 12 point italics

Tables, figures, line drawings, photographs and graphs Figures, Tables and Photographs should be placed in a separate set of files from the text (indicate in text desired location, e.g. with the phrase Table xx near here on a separate line in square brackets if possible). Each should be numbered sequentially with the title in Times New Roman 12 point font beneath. All figures and tables should be of high resolution. If possible figures and tables should be submitted in Excel (same table(s) could be in Word, in addition) and also if possible submit the data from which the figure has been produced.

Make sure all the denominations are according to international standards and the legends are clear.

Tables with suitable titles must be numbered using Arabic numerals in sequence and be understandable without reference to the text. Use a horizontal line to separate column headings from data and at the bottom

of the table; avoid column lines.

Excessive numbers of columns should be avoided.

Illustrations in the form of text figures, line drawings, and computer generated figures and graphs with their captions should all be comprehensible without reference to the text. All photographs should be half tone or colour, have a high definition (>5 million pixels/photo) and the software should be IBM/DOS compatible. Each photograph should be adequately identified with the author, paper and plate number.

Photographs submitted electronically must be in separate jpg files with the essential information included in the properties box for the file.

Alternatively, photographs may be posted to the Editor on disk (request address by e-mail). The plate number, authors and an indication of the paper title should also be given in a separate electronic file. Electronic-mail is satisfactory for correspondence, text and tables.

Standard deviations, standard errors of the means and “n”, the number of observations associated with each mean, should all be presented.

References and citations Papers should be fully referenced using the Harvard system in the format: author(s), each followed by their initials, the year of publication, the title of the paper, the journal title in full and in italics, the Volume number in heavy type, the Issue number, the first and last page numbers. Examples: Regan, D. & Smith, A. (1979) Electrical responses evoked from the human brain. Scientific American, 241, 134-52.

Klass, D. W. (ed.) Current practice of clinical electroencephalography. New York, Raven Press, 1979 ISBN n nn nnn nnn nnn.

Citation of authors in the text should appear in the form: Smith et al., (2005) or (Smith et al., 2005). More than one author should be cited in chronological order as: (Marcus, 2004; Cinti, 2005). If the same authors are quoted twice in a year, but in two papers the terms: (2005a; 2005b) should be used. If the same first author is quoted in two papers in a year, but with different co-authors then a list of a sufficient number of

them should be given to make it clear to which paper the reference relates: (Smith, Atkins, Jeans et al., 2005; Smith, Atkins, Sparks et al., 2005).

For internet references, use either Anon. (yyyy) or Organisation (yyyy) in the text. In the reference list provide the full URL with the date accessed, as for example: Anon. (yyyy) Webpage title and or subject. <http://www.organisation/page/file_or _other_address> accessed dd mmmm yyyy.

Communications with the Editor for publication Comments & Opinion and Letters to the Editor by e-mail will also be considered for publication. These should be concise and submitted for the purpose of making objective comments on published articles, or on important subjects that have not been covered.

Submission, Editing and Acceptance Manuscripts should be formatted to A4 justified using MS Word and 12 pt Times New Roman font. Authors’ names, qualifications, honours and affiliations should be included and submission will assume that the author accepts the conditions laid down in these Instructions to Contributors and that copyright is held by World Agriculture: problems and potential.

Manuscripts should be submitted to the Editor by electronic mail, with the address of: editor@worldagriculture.net.

Articles that are accepted by the editorial board will be edited and the Editor reserves the right to modify statements made by the author, or to ask for a revision, although the edited versions will be sent to the author for his or her agreement before publication. The author’s response must occur within 96 h. Moreover, during the revision process it is essential that authors respond quickly and reliably to requests for amendments, otherwise the publication deadline will be forfeited.

WORLD AGRICULTURE

55

56

6/4/11

14:35

Page 1

looking ahead

World Agriculture: potential future articles Anderson GalvĂŁo

New studies of biotechnology for agriculture in Brazil

Dr Tony Greer

Climate, Carbon and Conservation: Development Scenarios for the Coastal Peatlands of Sumatra and Indonesia

Prof. Brian J Ford

in vitro cultured meat, in a broad agricultural context Prof. Allan Buckwell The economics of British agriculture, County Land & Business Association Dr John Sheehy

Rice research, International Rice Research Institute, Manila, Philippines

Prof. James Crabbe

Oceanic adjustments to climate change and the food cycle

Subjects we intend to discuss further: Crop protection Disease control amongst animals and crops Developing technology Waste in storage and in transport Pest control Fuel crops Water economy Greenhouse gases â&#x20AC;&#x201C; removals/emissions 56

WORLD AGRICULTURE

Published by Wharncliffe Publishing, 47 Church Street, Barnsley, South Yorkshire S70 2AS

Back

6/4/11

14:51

Page 1

inside back page

8/4/11

13:12

Page 1

Dear readers,

If you wish to receive regular Issues of this Journal please complete the strip and post it to: Circulation Department, Wharncliffe Publishing, 47 Church Street, Barnsley, South Yorkshire S70 2AS or fax it to the publishers on 01226 734478.

Or fill in the form online at www.world-agriculture.net If you wish to place an advertisement in future Issues please in the first instance contact the Publishers by e-mail editor@world-agriculture.net or by post: World Agriculture, Wharncliffe Publishing, 47 Church Street, Barnsley, South Yorkshire, S70 2AS. If you wish to submit an article for consideration by the Editorial Board for inclusion in a Section of World Agriculture: a) Scientific b) Economic & Social c) Opinion & Comment, or d) a Letter to the Editor, please follow the Instructions to Contributors printed on Page 54&55 of this Issue and submit by e-mail to the Editor at the address given at the end of the Instructions.

For further information about World Agriculture please go to the following web address: www.world-agriculture.net Yours faithfully, David Frape

Name ..........................................................................................................

Business Address ......................................................................................... ................................. Email ..........................................................................

Contact number ..........................................................................................

Job title ........................................................................................................