Digging Deep: Soil, life and landscape

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Soil, life, landscape

Soil: Often overlooked, but something we cannot live without. This complex, living system beneath us supports nearly all life on Earth. Soil and the ecosystem services it provides govern everything from our supply of food and water to our ability to build resilience and regeneration amid a climate and nature emergency. Yet in both urban and rural environments, it continues to be mismanaged, degraded and destroyed.

It is high time that soil is brought to the fore of our professions across the built and natural environment. That’s why this edition of Landscape sets out to explain the vital importance of soil, and why the planning, design and management of landscape is so essential to its conservation and health.

Inside, President of the LI, Carolin Göhler, has gathered voices from across the industry to introduce current and future perspectives on soil, while Dr Stephen Carter and Ian Houlston FLI have recounted its historical relationship with the landscape. I am delighted to welcome colleagues from the Soils in Planning and Construction Taskforce as contributors to the edition, and to count myself as one of them, writing on soil and landscape-led development (p34). We are also pleased to bring you articles on contamination and remediation, regenerative agriculture, and manufactured soils, with a range of case studies throughout the edition articulating how landscape professionals can provide solutions.

If you want to make a difference to the future of the landscape profession, find out more about the LI Elections 2025 on page 66. There has never been a more important time to get involved with the Institute and impact the biggest challenges facing society today. Soil included!

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Landscape professionals are ideally placed to understand the role of soils in a project’s success and help to bring it up the agenda

Roisin O’Riordan

Find out more on page 20

Breaking new ground

Soil holds life together. It also holds together professions across the built and natural environments and demands that we work collaboratively to ensure that we value and restore our soils, helping them to help us.

Here, President of the Landscape Institute, Carolin Göhler FLI, introduces voices from across the industry to spotlight soil’s wide-ranging importance, and just a small amount of the current work taking place.

1. Early stages of a new housing development in East Anglia.

© Photo by Nickbeer on iStock.

Carolin Göhler FLI President, Landscape Institute

For some people it is ugly dirt, but soil really is beautiful: our true gold. It is even more precious now than we previously thought, as our growing understanding of it highlights the incredible benefits for people as much as for nature – if we look after it.

Throughout my career in horticulture and landscape, I have witnessed our understanding and awe of this complex underground ecosystem multiply. Not only is soil health important for healthy plants, but it also reduces the need for artificial fertilisers (along with their greenhouse gas emissions (GHG)). It acts as an important water store, retaining excess water like a sponge, and thus plays a valuable role in flood reduction. A healthy soil prevents erosion, reduces the need for irrigation during drought situations, enhances biodiversity, and is up to three times more effective at carbon sequestration than the plants and atmosphere above the surface.1

Soils’ natural capital supports most life on earth and plays a vital role in supporting multiple UN Sustainable Development Goals. Sustainable land management practices that work with nature to maximise soil performance, such as regenerative farming, could enhance crop yields and support healthier and enhanced food systems.

Increasingly, we are learning that lighter-touch management, such as low or no-till and no-dig methods, conserves the soil’s structure and its natural ecosystem of roots, fungi, and microbes. This regime also allows, for example, worms to be the incredible experts at recycling, nutrient dispersal and drainage that they are, continually improving the quality of any soil.

Creating and maintaining highquality soils in urban environments requires a thorough understanding, not only of soil as a system, but also of technological advances. These include growing substrates and soil reuse, with the implementation of such advances bringing new life to degraded landscapes. While improved specification is underway, we must stop prescribing peat in

any soil mixes (including pot-grown plant purchases) to make a positive climate impact and preserve rare wildlife habitats.

In both domestic policy and international forums such as COP (UN Conference of the Parties), a focus on soil has largely been absent. This is despite its critical role in human prosperity, as both a powerhouse in the carbon cycle and a key player in biodiversity conservation. We all have a duty to protect and improve soils, taking as many people as possible with us on the journey to understand, protect, and enhance our soils to benefit current and future generations. All of us, including landscape professionals, must collaborate more across the built and natural environment sectors, invest in soil health, and start valuing soils in a way we never have before. The health of society, as much as the beauty of our landscapes, depends on it.

1 https://www.american.edu/sis/ centers/carbon-removal/fact-sheetsoil-carbon-sequestration.cfm

From microscopic to landscape scale

Paul Hallett FI Soil Sci. President, British Society of Soil Science (BSSS)

Landscapes are built on the soil that arises from the geology underfoot, its weathering, and the driving forces of the life it supports. This creates huge complexity across natural landscapes but, in constructed landscapes, the greatest driving force of life can be the landscape professional overseeing the treatment of this precious resource.

Good landscapes promote biodiversity, including in the soil, with microorganisms and plant roots working in tandem to aggregate soil into beneficial biological habitats that balance water drainage and storage (Figure 1). Poor management – from compaction, mixing topsoil with subsoil, or stockpiling – leads to degradation of the soil’s biological habitat. Not only can this hinder biodiversity both below and above ground, but vital functions of landscapes such as drainage, amenity use, and the sequestration of atmospheric carbon will also be harmed.

Soil scientists use a range of tools to assess biological health in landscapes, ranging from simple visual assays accessible to all, to sophisticated explorations of microbial diversity through DNA analysis and 3D biological habitats in soil pores using X-Ray CT. When landscape professionals invest in good soil health through an understanding of the science, the benefits are extensive. Savings are made through reduced fertiliser use and irrigation demand, enhanced environmental benefits are realised from minimised flooding and increased carbon storage, and the outcome is happier clients.

Why microbes matter

Dr Marc Redmile-Gordon Senior Scientist for Soil and Climate Change, Royal Horticultural Society (RHS)

A healthy soil delivers vital ecosystem services, from methane removal to water storage. An aggregate held between your fingers is teeming with life and can house more microbes than the number of people living in London. Some cells live on their own, others cluster into groups called biofilms, but nearly all contribute to soil health. Microbes make sticky substances, called extracellular polymers, that improve soil structure and prevent erosion. A healthy soil has an open structure, both transmitting and storing water, that in turn protects our plants, soils, rivers, and water quality.

The RHS’ Soil Health Platform at Wisley supports investigations into soil health generation. Its aim is to help the UK become more sustainable by communicating our research and advice into climate mitigation and the value of different carbon pools and storage times. Treatments under investigation will include soil management practices, soil improvers, biostimulants, plants, and plant-products.

Parties interested in collaboration are invited to contact the author at Marc.Redmile-Gordon@RHS.org.uk.

2 Environmental horticulture for domestic and community gardens

– An integrated and applied research approach. Gush, M.B. et al., 2024, Plants, People, Planet

Figure 1: Biology and its habitat in soils links across scales from landscapes to microscopic. Roots bind soil at large scales. Microbes bind individual soil particles into aggregates. © Paul Hallett.

Figure 2: Conceptual diagram of a root supplying C as root exudates to microbes in soil aggregates. Microbes make water-absorbent films (EPS), helping soil health, plants, and climate.

Credit: RHS / Gush et al. (2024)2

3 https://research. reading.ac.uk/ nerc-nfm/wpcontent/uploads/ sites/81/2021/04/ Developing-deployinglow-cost-distributedmonitoring-to-evaluateNFM-compressed.pdf

4 Ibid

5 Ibid

6 https://cieem.net/ resource/guidelinesfor-ecological-impactassessment-ecia/

Soil and water

Alastair Chisholm Director of Policy, Chartered Institution of Water and Environmental Management (CIWEM)

As our climate changes, the role of soils as a crucial carbon sink will become more pronounced. Consequently, their ability to buffer against the effects of climate change will also become more important, not only to maintain agricultural productivity but also to maximise resilience to extremes of weather –both flood and drought.

Soils currently account for approximately 37% of water storage capacity in the UK.3 Many are not in good health or as spongy as they could be. That percentage would increase with good stewardship

and restoration through more regenerative agricultural approaches. Those in the know suggest that with better soil stewardship, the UK could enhance its food productivity despite climate change. Both studies and anecdotal evidence demonstrate that, in dry weather, regeneratively managed soils with increased organic matter content achieve elevated crop yields.4

A UK-typical 86-hectare farm could store 67,000m3 more water if regeneratively farmed,5 shielding downstream communities from flash-flood runoff commonly experienced with compacted soils that infiltrate water at a snail’s pace. This would also make more water available to nature in times of drought by sustaining vital base flows. Sponge soils really should be a no-brainer. We’re going to need them.

The role of soils in BNG

Dr Mark Nason MCIEEM

CERP

MI Soil Sci.

Head of Professional Practice, Chartered Institute of Ecology and Environmental Management (CIEEM)

Biodiversity Net Gain’s 30-year monitoring and management requirement highlights the need to focus on soil resources, as ecologists need to match habitat requirements to soil characteristics. They must also collaborate from the outset with soil scientists, landscape architects, and other stakeholders to consider complementary expertise and evidence, including knowledge of local soils and ecology. Failure to do so risks missing opportunities to identify, protect, and optimise the use of soils and soil-forming materials that may result in the recommendation of habitats that can’t be created, or the creation of habitats that can only be sustained through excessive management. Helping practitioners access guidance and tools to support evidence-based approaches and foster collaboration are key priorities for CIEEM. Our updated guidelines for Ecological Impact Assessment (EcIA)6 provide more advice on how soils should be considered, and we’re producing a new ecological restoration series with contributions from soil scientists and landscape architects. We’re also creating a biodiversity overlay for the RIBA Plan of Work as a tool to support multidisciplinary collaboration and help professionals deliver more for nature and people, from the ground up.

Right soil, right land use

CPRE, the Countryside Charity Graeme Willis Agricultural Lead

© CPRE

There is growing pressure on land, with geopolitical instability and climate volatility driving increased incidences of flood, drought, and fire. This perfect storm of factors is

undermining the certainty of how and where we can produce food in future, and in what quantity. Hence CPRE’s call for a stronger national planning policy to protect the best farmland and the most productive soils from built development is now an urgent imperative. Sadly, recent governments have instead consistently weakened the policy in order to drive short-term economic growth.

More positively, farmers are beginning to tap into the potential of regenerative approaches to reverse decades of soil neglect and harness natural processes to drive better land management. But to fully future-proof our domestic food supply, we must protect the extent of our best farmland soils and manage them back to health. We need the right policies on soils to be supported by investment in better tools and evidence. CPRE has recently demonstrated7 that a review of one key tool – the Agricultural Land Classification (ALC) system –

is essential. A revised and updated ALC should provide the evidence to underpin the government’s much anticipated Land Use Framework8 and other relevant planning and farming policies.

Towards soil reuse

Rachel

Boulderstone Head of Soil Health and Contaminated Land Policy, Department for Environment, Food & Affairs (Defra)

At Defra I oversee many aspects of soil health and contaminated land, focusing on the importance of healthy, resilient soil and ensuring we protect and reuse soil sustainably.

I am particularly interested in surface water flooding caused by compaction and believe correct practice that is relevant to soil type and land use is vitally important to support production, nature, and the environment.

In 2022, 24.7 million tonnes of soil were disposed of in landfill by the construction sector in England, making up nearly 60% of all waste sent to landfill.9 This was largely because soil reuse is not typically planned sufficiently early in projects, the soil itself can become compacted or degraded during earthworks, or it is not the right type for the scheme.

Defra’s Environmental Improvement Plan10 set a commitment to develop a Soil Reuse and Storage Depot scheme. The aim of this is to reduce the amount of soil going to landfill, facilitate appropriate soil storage, and encourage soil reuse. Following on from the recent Environment Agency report on its potential,11 I am planning further research that will inform the scheme’s development. The scheme will allow landscape architects to make recommendations to clients when soil reuse on site is not possible.

7 https://www.cpre. org.uk/wp-content/ uploads/2022/07/ Building-on-our-foodsecurity.pdf

8 https://www.gov.uk/ government/news/ government-launchesnational-conversationon-land-use

9 https://www.gov.uk/ government/statistics/ uk-waste-data/ukstatistics-on-waste

10 Environmental Improvement Plan, 2023, Defra

11 Potential for a Soil Reuse and Storage Depot scheme in England, Soils in Planning & Construction Task Force, Kourmouli, A. et al., 2024

Figure 4: Cholderton Estate regenerative farming produced for COP26.

© Merrick Denton-Thompson with terra firma

12 https://committees. parliament.uk/writtenevidence/62951/pdf/

13 https://www.hutton. ac.uk/sites/default/ files/files/Soils-A5booklet.pdf

14 https://climate. ec.europa.eu/system/ files/2016-11/soil_and_ climate_en.pdf

15 www.soilstaskforce.com/_files/ ugd/583ec4_ 160d0162e9ca45dca726ddbd5989d547. pdf

Joseph Lewis Policy Lead, Institution of Environmental Sciences

The importance of a holistic approach to soils is very clear: soil touches all aspects of the natural world and demands a joined-up response.

Soil is vital for carbon sequestration and can buffer against the effects of climate change. Healthy soils are also fundamental to ecosystems, supporting their biodiversity, nutrient cycling, and resilience.

Beyond their role in natural systems, soils are also deeply embedded in human systems. Soil is essential to the vast majority of food production and delivers substantial cultural and economic benefits.

Soils determine where we can build, and planning processes often contaminate soils or cause them to become waste. However, nature doesn’t recognise the boundaries we put on maps or the rings we draw around government departments. Some policy areas receiving the greatest benefits from healthy soil are inherently detached from the processes that determine whether those benefits are delivered, so a joined-up approach is essential.

Diverse planting for more resilient soil systems

Sheila Das Head of Gardens and Parks, National Trust

Public gardens can play a key role in demonstrating healthy soil management. For instance, conventional approaches have relied heavily on the use of bulky organic matter mulches such as manure or composted green waste. However, on-site composting, ‘chop and drop’ techniques, green manures, and living mulches can all be employed to reduce external inputs that are both costly and carbon heavy.

The move away from monoculture plantings and the introduction of a diverse range of plant roots in soils are supportive of soil biology. A range of root types (e.g. tap, fibrous, rhizomatous) and a selection of plant families (mixing woody and herbaceous for example) leads to an underground diversity that helps build a more complex and resilient system where nutrients are cycled in perpetuity.

The National Trust is experimenting with the management of rose gardens, adding varied underplanting to avoid the soil ‘sickness’ typical of conventional monoculture rose gardens (more accurately described as

an unbalanced soil microbiome). Observing and responding appropriately will be key to enjoying such features in the future without the use of pesticides. This requires an aesthetic shift, so communicating actions to visiting members of the public and ensuring we take people along on the journey will be key to success.

Collaborative working

Ellen Fay

Executive Director, Sustainable Soils Alliance (SSA)

Recognising that soil supports all life on earth and yet is undervalued, the SSA is a soil-specific organisation working to align voices across policy, business, and the land management sectors.

Statistics on soil are revealing: UK soils store an estimated 130 trillion litres of water;12 more living things are found in one teaspoon of soil than there are people on the planet;13 and soil also acts as the second-largest global carbon sink.14 Despite the critical roles that soil plays, in 2022 soil carbon losses due to urban development were estimated at 6.1 million tonnes.15

By bringing diverse stakeholders together to address soil degradation and advocating for effective, collaborative solutions, the SSA bridges the gap between landowners and managers, leading soil scientists, and businesses. To this end, the SSA aims to embed soil health in sustainability goals that are aligned with on-the-ground practices, helping stakeholders understand the importance of soil health in achieving broader environmental objectives. Through educational initiatives, policy advocacy, and partnerships, the organisation encourages investment in soil protection and restoration for the delivery of mutual benefits, such as increased productivity, safeguarding carbon, and more resilient ecosystems.

Figure 5: Diverse plant roots support soil biology. Wildflowers in June at Godolphin, Cornwall. © National Trust Images/James Dobson

Earthlings

Soils tell a fascinating story of humankind’s interaction with the earth over the centuries, if we know where to look.

Dr Stephen Carter FSA Scot MCIfA Ian Houlston FLI MCIfA

Soil is not usually considered a cultural artefact. Yet, like any other artefact that we take in our hands, it presents a visceral opportunity to understand our relationship with the world around us and can tell us much about our past. Despite this, there is arguably a greater cultural disconnect today with the soil than with any other ecosystem.

Even those of us who have sought to understand the landscape may not see the explicit links between soils, their management, and the elements

and features that form the setting to our everyday lives. However, the evidence is there, to be read like the pages of a book. For soil contains a record of the complex interplay of ecological and cultural forces over time and reveals the story of the human journey.

Human impact on soil development first emerged with the advent of farming in the Near East around 12,000 years ago, which spread or emerged independently to become the predominant form of food

1. December on the Downs by Percy Shakespeare depicts the animal-driven ploughs that first gave rise to ‘ridge and furrow’ fields, alongside the advent of mechanised farming methods that have contributed to the degradation of agricultural soil since the Second World War. © Alamy

production on the planet. Agriculture tied communities to the land, changing attitudes to its ownership and the sharing of resources and helping to lead to the creation of towns, cities and civilisation – the world we inhabit today.

The earliest tangible evidence of farming in Britain ranges in scale from microscopic changes in soil structure and composition, to radical modification of entire landscapes. Individual plough marks have been preserved in soils buried beneath Neolithic monuments, such as the South Street long barrow in Wiltshire,1 while the clearance cairns of Neolithic and later times, built from stones brought to the surface by tillage, survive in upland areas. Man-made or ‘plaggen’ soils, created by the extensive stripping of soil from one part of the landscape and its deposition on cultivated land elsewhere, were also widespread.2

On the island of Papa Stour, Shetland, prolonged stripping of turf for manuring has created two distinct landscapes: impoverished pasture over shallow rocky soils in the western half,

and farms with deep fertile cultivated soils in the east.3

However, the impacts of these deliberate modifications are dwarfed in scale by unintended processes, such as soil movement arising from clearing vegetation on slopes. For example, the distinctive landscape of the chalk hills of southern England may look entirely natural but it is in large part a product of prehistoric agriculture.4 In the early Holocene, these hills were covered in deep soil from the blanket of windblown silt (loess) deposited during the preceding ice age. Clearance of woodland in the Neolithic and Bronze Ages triggered widespread erosion, exposing the shallow, chalky soils and characteristic vegetation that are familiar today. Similarly, a direct consequence of widespread humaninduced erosion in the uplands of Britain was a major change in the flow regimes of lowland rivers, as large quantities of sediment were washed into them. The present-day form and land-use of valley floor and floodplain landscapes owe much to this erosion of upland soils.

As populations increased, new ways to work and manage both land and soils emerged, including the advent of the heavy plough5 and digging of ditches, which allowed more land to be cultivated. Changes in land tenure also played a role. Across much of lowland England, common or open field systems, both regular and irregular, came to dominate the postRoman rural landscape. A process of rotation allowed a proportion of available soils to lay fallow and regain nutrients through grazing; another area to be planted with peas, beans or lentils to fix nitrogen; while cultivation of cereal crops occurred elsewhere. Units or strips within these fields, sometimes termed ‘lands’ or ‘selions’, were arranged in coherent blocks (furlongs) and separated by ditches or ridges called ‘headlands’. Serving to reinforce the separate nature of the strips and to facilitate drainage of the soil, mouldboard ploughing by teams of oxen created distinctive ridges and furrows that can still be seen today where they have been preserved under permanent pasture.

2. Ancient ridge and furrow fields at sunset, Gloucestershire, UK; aerial view. © Alamy

1 Ashbee, Paul & Smith, I. & Evans, J. (2014) ‘Excavation of Three Long Barrows near Avebury, Wiltshire’. Proceedings of the Prehistoric Society, 45, 207–300

2 Groenman-van Waateringe, W. and Robinson, M. (1988) ‘Man-made Soils’, Symposia of the Association for Environmental Archaeology No.6, BAR International Series 410

3 Carter, S. and Davidson, D. (1998) ‘Interpreting the Soil Landscape of Papa Stour’ in Turner, V. (ed.) The Shaping of Shetland, 128–137. The Shetland Times Ltd, Lerwick

4 Bell, M. and Boardman, J. (eds) (1992) Past and Present Soil Erosion. Archaeological and Geographical Perspectives. Oxbow Monograph 22. Oxbow Books, Oxford

5 Thomas Barnebeck

Anderson et. al. (2015) ‘The heavy plough and the agricultural revolution in Medieval Europe’. Journal of Development Economics

4. London nightmen,

6 Historic England (2018) Pre-industrial Lime Kilns: Introductions to Heritage Assets. Historic England. Swindon

7 https:// historicengland.org.uk/ listing/the-list/list-entry/1021105? section=official-list-entry (accessed December 2024)

8 https://www.bonemill.org.uk/ (accessed December 2024)

9 https://english. alarabiya.net/lifestyle/2022/07/18/ Bones-of-soldierskilled-in-1815-Battleof-Waterloo-may-havebeen-sold-as-fertilizer(accessed December 2024)

Despite these innovations, local conditions remained the main determinant of soil productivity until the 18th century. At that time, advancements in science, technology and engineering led to a revolution in farming, and a much greater degree of homogenisation in the rural landscapes of Britain.

Lime kilns from the Romans onwards had enabled the smallscale production of quicklime which was mixed, or slaked, with water to make plaster, mortar, concrete, and lime-wash.6 But the widespread ‘sweetening’ of acidic soils by the regular spreading of calcined limestone, was made possible by the railways, bringing into production vast tracts of otherwise marginal land. Trains could transport the quantities of fuel required to operate industrial kilns such as Bellmanpark in Clitheroe and take the lime to rural markets.7

Bone was also used to fertilise soils. Roughly crushed bones were used to renovate pastures in Britain in the late 18th century, but quicker results were obtained by using the finely ground bonemeal produced in crushing mills. Narborough Mill8 in Norfolk, for example, processed a steady supply of bonemeal from whale bone that came from a blubber processing factory in Lynn. When whale bone was not available, local farms and slaughterhouses supplied the mill, and villagers would also take down “a penn’orth of bones to be ground”. The mill would also process human bones exhumed from cemeteries and few at the time would have questioned the ethics of this. Ships docking at Lynn allegedly included exhumations from German burial grounds, leading to the blithe expression that “one ton of German bone-dust saves the importation of ten tons of German corn”. In fact, so lucrative was the trade that it has recently been argued that the reason it is surprisingly hard to find the remains of soldiers that fell on Europe’s battlefields, such as Waterloo, was that their bones were collected to be sold to make fertiliser.9

Improved transport links in the 19th century also enabled growers to serve distant markets. In Devon,

3. Battle of Waterloo 1815.

© William Sadler, Public domain, via Wikimedia Commons

circa 1862. © Alamy

for example, the market gardens at Morwellham Quay produced early season strawberries that were transported by rail across the country, attracting a premium price. These market gardens were fertilised by ‘night soil’ (human waste) collected from the inhabitants of Plymouth. Fragments of fine porcelain cups and clay pipes that found their way into the great heaps of night soil can still be found in Morwellham’s fields today. Evidence of draining waterlogged soil for cultivation goes back centuries: rivers such as the Ouse were straightened and new channels cut in the late medieval period. But draining at scale is relatively recent. It was the ‘Gentleman Adventurers’, led by the Earl of Bedford in the mid-17th century, that set out to drain the Fens of eastern England. Wealthy landowners employed Dutch engineers such as Cornelius Vermuyden to spearhead schemes in the face of opposition from locals, such as the Fen Tigers, who feared the loss of their traditional income from wildfowling, fishing and

reed cutting.10 So effective was this engineering that the land sank as the peat dried and contracted, leaving the banks of rivers and dykes higher than the surrounding fields. Pumps, elaborate sluices, and drains are still deployed today to prevent some of the country’s most productive farmland from flooding.

Less dramatic, but equally as transformative, was the widespread use of tile drains in the early 19 th century, to make waterlogged soils suitable for cultivation. Previous methods of ‘under drainage’, such as lining trenches with brushwood, had been used for generations. However, the Public Money Drainage Act of 1840 provided landowners with loans to undertake large-scale tile drainage schemes.11 Over the following half century, it is estimated that around 12 million acres of land were drained.12 These works, while ubiquitous across the country, are a hidden soil story, only in evidence where clay pipes are occasionally dug up and exposed. So, even with a short fly-through,

we can see how a focus on soil helps us to see landscapes afresh, and that human activity has heavily influenced soil’s properties, alongside factors such as geology, relief, climate, vegetation – and the passage of time.

As the thin but astonishingly diverse layer on which our lives entirely depend, soil is among the most important of ecosystems. Most

Evidence of draining waterlogged soil for cultivation goes back centuries: rivers such as the Ouse were straightened and new channels cut in the late medieval period.

10 https://www. greatfen.org.uk/aboutgreat-fen/heritage/ brief-history-greatfen#:~:text=In%20 1630%20a%20 group%20of,by%20 a%20grant%20 of%20land (accessed December 2024)

11 Darby, H.C. (1964) The Draining of the English Clay-Lands. Geographische Zeitschrift

12 https://www. trenchers.co.uk/ products/agriculturaldrainage-trenchers/abrief-history-ofagricultural-drainage/ (accessed December 2024)

5. The Holme Fen Posts record the shrinking of the land as the water drained out of the peat fens during the 19th and 20th centuries.

© Holme Fen Posts by Roger Cornfoot, CC BY-SA 2.0

13 https://www. unesco.org/en/articles/ spreading-open-andinclusive-literacy-andsoil-culture-throughartistic-practices-andeducation-0 (accessed January 2025)

14 Brian K. Roberts and Stuart Wrathmell (2002) Region and Place: A Study of English Rural Settlement, English Heritage

modern farming seeks to radically simplify ecosystems, and the UK has been as extreme as anywhere, resulting in grave biodiversity and habitat loss.

The chemical fertilisers and mechanised farming widely deployed since the Second World War are designed to maintain yields from repeat cropping. Nearly all of this has come at the expense of the health of soil and biodiversity, with millions of hectares being compacted, eroded, degraded, and contaminated to the point that we are poisoning our own water sources.

The way that soil is treated in the future will reflect cultural values and priorities. UNESCO has become sufficiently alarmed by widescale soil degradation as to launch a major new public awareness programme,

Soilscape,13 to harness the power of culture and creativity to improve soil literacy.

While much of the UK’s farming industry continues to place its faith in engineering and technology, traditional approaches are again taking hold. Practices such as crop rotation, agroforestry, and regenerative agriculture all showcase a deeper understanding of soil health.

The 20th-century German philosopher Martin Heidegger used the term Bodenständigkeit (rootedness) to describe the human connection to the earth and the importance of living authentically within one’s environment. As a society, we need to chart our way back to the rootedness that will enable us to return our living planet to a healthy state. We

could start by recognising how far soil is from a wholly natural phenomenon, “derived complete from the hand of nature”,14 and instead a cultural artefact for which we are responsible.

Dr Stephen Carter FSA Scot MCIfA is a Heritage Consultant at Headland Archaeology.

Ian Houlston FLI MCIfA is a Director at LDA Design, a member of the Landscape Institute Policy & Public Affairs Committee, and founder of the Chartered Institute for Archaeologists’ Landscape Special Interest Group.

Together they co-direct the Setting of Heritage Assets Course at the Oxford University Department for Continuing Education.

6. A windmill, Wicken Fen Nature Reserve.

© Karen Cann, Unsplash

Healthy soil, healthy places

From flood mitigation and vegetation support to antibiotics and our immune systems, healthy soils underpin healthy people and places. Landscape professionals understand these myriad benefits and are well placed to employ their unique skillset to mitigate risk and promote best practice.

When soil is healthy it provides many functions, or ecosystem services – the benefits that we, as society, get from nature. These include food production, carbon storage, mitigation of flooding and drought, detoxification of pollution, and protection from diseases.

Soil provides this multifunctionality through its physical, biological, and chemical properties. In practice, this means that healthy soil has good structure, a diverse biological community of organisms, and plenty of organic matter and nutrients. Healthy soils support the growth of plants, including crops and, given that 95% of global food production relies on soil,1 its health plays a vital role in food security. Soil is also a living system; it’s estimated that 59% of all life on earth lives in soil, making it the world’s most species-rich habitat.2 Its health determines how well it functions as a living ecological entity and, equally,

its capacity to provide for our health, wellbeing, and ability to function as a society.

Urban soil multifunctionality and biodiversity

In cities and urban areas, soils still provide important functions; they are simply less visible than in farmland or natural landscapes. Contrary to expectations, soils in urban greenspaces and gardens can be healthier than many agricultural soils, although they still experience pressures, such as high footfall. Urban soils underpin many ecosystem services that are important for both Roisin O’Riordan

1 Soil structure and its benefits, Royal Society, 2020

2 Enumerating soil biodiversity, Anthony, M.A. et al., 2023, Proceedings of the National Academy of Sciences (PNAS)

3 The Urban Heat Island: Implications for Health in a Changing Environment, Heaviside, C. et al., 2017, Current Environmental Health Reports

4 The ecosystem services of urban soils: a review, O’Riordan, R. et al., 2021, Geoderma

2. Research now suggests that human health is influenced by exposure to natural environments, including soil

5 Biogeographic patterns in belowground diversity in New York City’s Central Park are similar to those observed globally, Ramirez, K.S. et al, 2014, Proceedings of the Royal Society B: Biological Sciences

6 Role and management of soil biodiversity for food security and nutrition; where do we stand? El Mujtar, V. et al., 2019, Global Food Security

7 Biodiversity and ecosystem function in soil, Fitter, A.H. et al., 2005, Functional Ecology

human wellbeing and urban resilience. These include local flood mitigation, buffering the urban heat island effect,3 supporting urban vegetation that captures air pollution, access to greenspace for health, and urban food growing.4

Urban soils are full of biological life.

A study of Central Park in New York showed that the diversity of microbial life in the park soil was as broad as that found in soils across the globe, in natural ecosystems from multiple continents.5

Soil organisms can be categorised into three groups according to their function: ecosystem engineers, chemical engineers, and biological regulators.6 Ecosystem engineers are larger soil animals such as earthworms, ants, and small mammals. They ingest or move large amounts of soil and incorporate organic matter into the soil matrix. Chemical engineers are decomposers; these are smaller microorganisms (or microbes) that include bacteria and fungi. Their

role is to decompose plant residue and other organic matter, transforming nutrients so that they are available to plants. Biological regulators are microorganisms (protozoa, nematodes) or larger organisms (springtails, mites). They act to regulate the population of other soil organisms, either through predation or by releasing chemicals, such as enzymes, antibiotics or

hormones. This also gives them the potential to control soil diseases. These incredible organisms not only perform important functions in soil, but their activities also drive ecosystem processes that govern global systems such as nutrient and carbon cycling,7 and have a significant influence on human health, society, and the planet.

1. Soils in urban green spaces and gardens canbe healthier than many agricultural soils

Photo by Gary Butterfield on Unsplash

Photo by Kurt Bouda on Pixabay

2.

Healthy urban greenspaces

Ecosystem engineers physically alter soil structure and help to form soil aggregates (clumps of particles that are bound together). In soils with good structure there are numerous pore spaces between aggregates where water and oxygen can be stored. Earthworms and plant roots maintain that structure by forging a network of pathways and tunnels through the

soil, creating infiltration channels for hydration and respiration to take place. In urban greenspaces, soils can be less compacted than agricultural soils,8 with ample pore spaces that support healthy vegetation. It’s well known that access to good-quality greenspace contributes to our wellbeing and is associated with improved mental and physical health outcomes.9

Healthy soils in our greenspaces also store carbon in the form of organic matter. Storing more carbon helps contribute to climate change mitigation as well as making our soils more resilient to the impacts of climate change.

Soil compaction, on the other hand, creates a serious problem. It restricts pore spaces so prevents water either infiltrating or being stored. This in turn leads to waterlogging or flooding during wet weather and increased drought during dry weather. Compaction also prevents oxygen from entering the soil, making it inhospitable to many soil organisms, plants, and trees. On construction projects, soil compaction is a major cause of soil degradation. It occurs due to trafficking by heavy vehicles, inappropriate soil stockpiling and reinstatement, and can render the soil incapable of supporting plant growth. Over time, soil ecosystem engineers can improve the soil, but it may take years to recover. So it’s vitally important that we prevent damage to soils during construction in order to deliver successful greenspaces.

Healthy soils in our greenspaces also store carbon in the form of

organic matter. Storing more carbon helps contribute to climate change mitigation as well as making our soils more resilient to the impacts of climate change. Organic matter allows soil to hold more water, helping plants survive drought and reducing dust or wildfire risk. Increased organic matter and soil carbon can be encouraged in the landscape by planting trees, shrubs, deep-rooted grasses and perennials, and limiting physical disturbance or compaction of the soil. Healthy and well-managed soils in established greenspaces and gardens act as vital pockets for infiltration, oxygen, and carbon within largely impermeable urban landscapes.

Contamination risks in urban soils

Soil helps to capture contamination, and microbes are then able to biodegrade some organic pollutants.10 As such, soils and microbes play a part in the transport, bioavailability, and risk posed by contaminants.11 While it is beneficial for soil to capture contaminants and prevent them reaching groundwater, build-up can lead to soils becoming a health risk. This is particularly the case in urban soils where greenspaces can be a repository for historical and current contamination and are also locations where people have more contact with soil.12

3. Ecosystem engineers physically alter soil structure and help to form soil aggregates (clumps of particles that are bound together).

8 Are soils in urban ecosystems compacted? A citywide analysis, Edmondson, J.L. et al., 2011, Biology Letters

9 Improving access to greenspace, Public Health England, 2020

10 Microbial degradation of different hydrocarbon fuels with mycoremediation of volatiles, Horel and Schiewer, 2020, Microorganisms

11 The role of soils in the disposition, sequestration and decontamination of environmental contaminants, Sarkar, B. et al., 2021, Philosophical Transactions of the Royal Society B

12 Urban soil and human health: a review, Li, G. et al., 2018, European Journal of Soil Science

3.

Photo by Sippakorn Yamkasikorn on Unsplash

4. New river walk community planting, part of Camden.

@ Islington Parks for Health programme. Read more about the vital role of urban parks in the Autumn 2023 edition of Landscape.

@ Islington Council - Vanessa Berberian

13 dwi.gov.uk/pfas-andforever-chemicals

14 Environmental challenges threatening the Growth of urban agriculture in the United States, Wortman, S.E. and Lovell, S.T., 2013, Journal of Environmental Quality

15 Plants oxidative response to nanoplastic, EknerGrzyb, A. et al., 2022, Frontiers in Plant Science

16 Renaissance in antibacterial discovery from actinomycetes, Baltz, R.H., 2008, Current Opinion in Pharmacology

17 Environmental biodiversity, human microbiota, and allergy are interrelated, Hanski, I. et al., 2012, Proceedings of the National Academy of Sciences (PNAS)

18 Soil and human health: current status and future needs, Brevik, E.C. et al., 2020, Air, Soil and Water Research

19 Environmental exposure to endotoxin and its relation to asthma in school-age children, BraunFahrländer, C. et al., 2002, New England Journal of Medicine

20 Code of practice for the sustainable use of soils on construction sites, 2011, Defra

In urban food growing, heavy metals, perfluoroalkyl and polyfluoroalkyl substances (PFAS), forever chemicals13 and other contaminants can pose a risk. For example, although lead can accumulate at low levels in plant tissue, the main risk pathway is considered to be ingestion through aerosols, such as dust inhaled during digging, or soil attached to unwashed produce or hands.14 Soil is also a sink for micro- and nanoplastics, the latter of which can be taken up by plant roots and leaves,15 and may find their way into food grown in urban areas. However, there remains a great deal of uncertainty around the long-term impacts of microplastics on human health.

Soil microbes and human health

Soil microbes also have the ability to control human pathogens and over 70% of naturally occurring antibiotics that we use in medicine come from soil organisms.16 However, the widespread use of antibiotics has led to antibiotic resistance, and this may be increasingly present in soil due to the use of antibiotics in livestock, and through manure or wastewater. To protect the use of soil as a source of

antibiotics, we need to maintain its microbial diversity and prevent the loss of microbial species through soil degradation.

Research now suggests that human health is influenced by exposure to natural environments, including soil.17 It is thought that exposure to soil microbes likely plays a role in the development of the immune system,18 and that this exposure is linked to microbially driven immune responses that influence mental and physical wellbeing. It has been shown that early life exposure to microbes can promote tolerance to allergens. For example, children in rural areas exposed to microbial endotoxins tend to have fewer allergies than those from urban areas.19

Why

we need to take a holistic approach to landscape and soil

Working as a landscape architect requires holistic thinking, bringing together many professions and stakeholders to understand a site and deliver what’s needed. The broad nature of this work means landscape architects are ideally placed to understand the role of soils in a project’s success and help prioritise it on the agenda. Soil is often taken into

consideration too late in a project and, as such, is not always well planned for.

Talk about soil with clients early in the planning stage, design with the site’s soil health in mind, and treat soil as a living ecosystem. Use Defra’s guidance on the sustainable use of soils on construction sites.20 You might also bring in soil scientists by using the British Society of Soil Science ‘find an expert’ service.21

Working with nature is crucial for sustainable and forward-looking design, so use it to support healthy, functioning soils with rich biodiversity. Not only will it support more successful greenspaces and projects, but it’s also an opportunity to improve the health of people, ecosystems, and society.

Roisin O’Riordan worked as a landscape architect and in an environmental NGO before moving into soil science. She’s now in the soil and peat science team at Defra where she gathers evidence to support policymaking. Her interests are in soil ecosystem services, soil carbon and soils in planning and construction.

21 soils.org.uk/find-anexpert/ 4.

Policy outlook: Soils and the built environment

The co-leaders of the Soils in Planning and Construction Task Force set out the current policy and regulatory landscape of soil in the built environment, highlighting the action required for greater soil sustainability.

Birgit Höntzsch

2.

© John Quinton

1 Global Land Outlook

2nd edition, 2022, UN

2 The state of soils in Europe, 2024, European Commission Joint Research Centre

3 Agricultural Land Classification: protecting the best and most versatile agricultural land. Natural England Technical Information

Note TIN049, 2012, Natural England

4 Enumerating soil biodiversity, Anthony, M.A., et al., 2023, PNAS

5 https://claire. co.uk/projects-andinitiatives/dow-cop

Soils, generally, have long lacked strong governance, despite the consequences of soil degradation being well understood. For example, 90 years ago, the Dust Bowl drought in the US saw over a billion tonnes of soil blow off the Great Plains, devastating both local communities and the economy. This disaster prompted the creation of the world’s first soils policy, the Soil Conservation Act, under President Franklin Roosevelt, who famously warned, “The nation that destroys its soil destroys itself”.

Yet in the decades that followed, soils remained, in many countries, unprotected and ungoverned, with little more than voluntary guidance or advice on sustainable soil management. This has contributed to the alarming state of soils today, where 40% of the world’s soils are classed as degraded by the UN,1 with estimates reaching as high as 60–70% for Europe.2

The past 10 years, however, have seen a major surge in international soil policy interest and innovation. The 2015 adoption of the IPCC (Intergovernmental Panel on Climate Change) Paris Agreement highlighted the role of agricultural soils in mitigating climate change, elevating soils on the global policy agenda. The UN’s International Year of the Soil, also launched in 2015, further emphasised the critical multifunctional role of soils. Since then, the EU has introduced a Soil Strategy for 2030 and established its first Soil Monitoring Law. Similarly, soil-related policies have become more prominent across the four nations of the UK, for example through Northern Ireland’s Soil Health Nutrient Scheme, the Sustainable Farming Incentive in England, and the Sustainable Farming Scheme in Scotland.

However, policy has largely focused on soils in agricultural and natural environments and the regulation and consideration of soils in the built environment lags significantly behind. In the UK, policies and guidance on soils in planning and construction are highly fragmented, narrow in scope, and predominantly voluntary. For example, the National Planning Policy Framework only awards value to soils with a statutory status (e.g. peatlands) or those identified as of good quality, as described by the Agricultural Land Classification (ALC). The ALC alone, however, is insufficient for assessing the full role of soils in sustainable development, as acknowledged by Natural England.3 It focuses on only one ecosystem service – food production – and ignores the significance of soils in other ecosystem services such as water storage and flow regulation, carbon storage and climate regulation,

or in supporting biodiversity, given it is home to more than half the species on earth,4 In England, Defra’s Code of Practice for Sustainable Use of Soils on Construction Sites offers valuable guidance on soil functions and best practice but remains a voluntary measure with limited adherence in practice. An updated version of this code is expected soon.

Currently, most of the rules, regulations, and advice on soils in construction centres upon handling soil as a waste product. Soils that need to be removed from construction sites are automatically classified as waste and must be disposed of at licensed facilities as inert, hazardous, or non-hazardous material. In England and Wales, if there is certainty of use, soils can be reused on-site without waste controls applying under the Definition of Waste Code of Practice (DoWCoP).5 This is a voluntary industry code of practice from CL:AIRE (a UK charity committed to providing a valuable service for all those involved in sustainable land reuse). However, if storage duration exceeds 12 months or the DoWCoP conditions are unmet, a recovery permit from the Environment Agency is required. For reuse of soils on other sites, specific environmental permits or exemptions under the DoWCoP must be obtained.

Jessica Davies, John Quinton

Soils are the Earth’s fragile skin and they need protecting.

While there are some potential pathways for soil use or reuse in construction, the volume of soil sent to landfill in the UK remains alarmingly high. An analysis of England’s waste data for 2023 highlights that 55 megatonnes (Mt) of soil waste were received by permitted facilities in England that year.6 Only 1.5% of this was classed as hazardous waste. Over half of the soil waste classified as inert (more than 25Mt) was sent to landfill.

To put these numbers into perspective, the mass of soil sent to landfill from development and construction sites is approximately eight times greater than the annual soil loss from erosion on agricultural land across all of England and Wales. This is especially striking given that agricultural land covers a vastly larger area than land under construction. These figures underscore the urgent need for more sustainable and efficient soil management

The mass of soil sent to landfill from development and construction sites is approximately eight times greater than the annual soil loss from erosion on agricultural land across all of England and Wales.

practices within the construction sector.

Why does so much soil end up in landfill? While there are some pathways to reuse, there is a complex set of factors driving this trend. Poor early planning, lack of space on-site, and inadequate on-site monitoring can lead to soils being classed as waste. Waste storage exemptions available through the Environment Agency can also restrict the volume and timeframe for soil storage. Current attitudes towards soils also contribute: soil reuse is often seen as timeconsuming and costly (even though reuse could reduce costs in machine time, fuel and topsoil imports), with landfill disposal considered a cheaper and more convenient option. Waste misclassification and crime further exacerbate the issue as soil is frequently mislabelled or mixed with demolition waste to evade higher taxes, reducing its potential for reuse.

3.

4. We have tree protection zones; what protections are in place for soils?

© Birgit Höntzsch

5. Reuse of soils on-site requires careful planning and management.

© Birgit Höntzsch

Additionally, economic fluctuations and large-scale infrastructure projects create uncertainty in soil supply and demand, making reuse planning difficult under the current system. Addressing these barriers requires regulatory reform, better planning, and stronger financial incentives for sustainable soil management.

The problem of this ‘waste’ has been acknowledged by policymakers. In the 2023 Environmental Improvement Plan, the government committed to developing a pilot Soil Reuse and Storage Depot Scheme by 2026 to help reduce soil waste by encouraging reuse and remediation. Recommendations for this scheme have recently been made, including the development of soil hotels (fixed facilities for the temporary storage of clean soils for reuse) and soil hospitals (where contaminated soils are remediated or improved to allow reuse).

While these commitments and proposed new schemes to reduce soil waste and enable reuse are encouraging, the significance of soils to sustainable urban development goes far beyond the management of waste. Soils are the foundation of sustainable development, and if considered and treated well throughout planning and construction, they could contribute positively to carbon sequestration and climate commitments, supporting biodiversity above and below ground, and mitigating the risks of floods and heat waves.7

Humanities Research Council, with support from Lancaster City and Cornwall Councils. It has focused on the development of ‘model policies’ for local authorities on soil sustainability (see case study, p32). Over 40 representatives across UK policy and industry have been engaged in the development of this guidance through focus groups and in-person co-design workshops, the results of which will be shared soon through the Soils Task Force.

Ultimately, there is some distance to go to achieve soil sustainability in construction, both in the UK and globally. Strong policy is important, but pragmatic changes in practice will require not only policy innovation, but also cross-sector collaboration and buy-

in. The future of our soils, and our built environment, depends on the decisions of many throughout the development process. Working together is the only way to ensure this vital resource is not treated as dirt. If you are interested in working with us or in the Task Force, please get in touch.

at soilstaskforce.com

Jessica Davies is Professor of Sustainability and John Quinton is Professor of Soil Science at Lancaster University. Together they lead the Soils in Planning and Construction Task Force.

7 The ecosystem services of urban soils:

A review, O’Riordan, R. et al., Geoderma, 2021

8 https://www. soilstaskforce.com/ reports

9 https://www. soilstaskforce.com/ about/local

The cross-sector Soils in Planning and Construction Task Force is active in promoting a fuller appreciation of the multifunctional value of soils and supporting the adoption of soil sustainability in practice. The Task Force’s work, which can be found on our website,8 has highlighted that local planning policy is a key leverage point. Through this, requirements and mechanisms that deliver soil sustainability throughout the development timeline – from preplanning to post-development – can be embedded. A recent project,9 Local Soils, has been funded by the Engineering and Physical Sciences Research Council and Arts and

Road construction site.

Photo by Troy Mortier on Unsplash

Soil carbon and construction

Birgit Höntzsch Dipl-Ing CMLI

Soil is the second largest carbon store on earth, embedded in a complex carbon cycle that has been devastated by human activity. The construction industry is a prime culprit, making it vital that soil is put first and foremost in any development.

1. On construction sites, minimising compaction and retaining as much soil as possible in a healthy condition can go a long way to protecting the soil’s carbon storage and processing abilities.

Photo by CatLane on iStock

Soil is a complex system of organic matter, minerals, water, air and organisms that has developed over hundreds of thousands of years, forming the thin outer layer of the earth that supports life. For this reason, our soil systems are considered a non-renewable resource.

Soil, water and air are core components that define our climate and foundation of life on earth as we know it today by supporting complex living organisms and habitats and enabling humanity to thrive. Due to human impact, the current rate of change to these systems has accelerated beyond change that would naturally occur, thereby accelerating climate change and biodiversity loss.

Soil carbon storage and the carbon cycle

The carbon cycle is complex, and after our oceans, soils are the second largest carbon store on earth. Yet they bear a high proportion of that human impact upon our natural resources – through activities such as agriculture, deforestation, mining, and construction.

The Office of National Statistics (ONS) published experimental data on UK biocarbon stock in 2016. This demonstrated the importance of carbon stored in soils, since it vastly exceeds carbon stored in the vegetation growing on these soils. Wetlands are very effective carbon sinks, and forests also store significant amounts of carbon both below and above ground.

The ONS states:

“There was an estimated 4,266 million tonnes of carbon (MtC) of recorded biocarbon in the UK in 2007, of which 94.2% (4,019 MtC) was contained in soil stocks and 5.8% (247 MtC) in vegetation stocks.

Between 1998 and 2007, UK biocarbon stocks declined by approximately 19.9 MtC (-0.5%), on the back of a fall in the volume of carbon stored in soil stocks. Carbon contained in UK vegetation rose by 1.3 MtC (+0.5%) during the decade to 2007, driven by an increase in categories of forest tree cover.”1

1: Carbon dioxide (CO2) in the atmosphere is fixed by plants (or autotrophic microorganisms) and added to soil through processes such as (1) root exudation of low-molecular weight simple carbon compounds, or deposition of leaf and root litter leading to accumulation of complex plant polysaccharides. (2) Through these processes, carbon is made bioavailable to the microbial metabolic “factory” and subsequently is either (3) respired to the atmosphere or (4) enters the stable carbon pool as microbial necromass. The exact balance of carbon efflux versus persistence is a function of several factors, including above ground plant community composition and root exudate profiles, environmental variables, and collective microbial phenotypes (i.e., the metaphenome). Figure inspired by Bonkowski, 2004.

Figure

Credit: Dan Naylor, Natalie Sadler, Arunima Bhattacharjee, Emily B. Graham, Christopher R. Anderton, Ryan McClure, Mary Lipton, Kirsten S. Hofmockel and Janet K. Jansson, CC BY-SA 4.0

Figure 2: UK biocarbon stock estimates (MtC).

“The subsoil has a large influence on ecosystem productivity and the supply of ecosystem services. Carbon stored in subsoils generally contributes to more than half of the total stocks within a soil profile.”

What is soil carbon?

Soil Organic Matter (SOM) describes the organic matter content created by plants and animals, such as roots, leaf matter, and animal detritus, in various stages of decomposition. SOM also includes carbon, referred to as Soil Organic Carbon (SOC). SOC is created through physical, chemical and biological processes, and we can assess how much carbon is stored in a particular soil.

Soil carbon in the form of organic matter is highly beneficial for soils and future planting, as it contains nutrients, improves water storage, binds polluting elements, enables microorganisms to live in soil, and supports root growth.

SOM is key to a soil’s role in climate mitigation and is often negatively affected by construction projects. If soils are removed from site, the SOM will be removed along with it. Compaction and storage affect SOM and construction-related activities can significantly reduce or lead to loss of carbon storage capabilities. Damaging soils in this way may also result in the release of GHG back into the atmosphere due to changed or interrupted decomposition processes. This removes stored carbon from a site, thereby negatively affecting a project’s carbon credentials.

In 2013, soil carbon losses due to development were estimated at 6.1

million tonnes of CO 2; this is greater than the emissions of GHG from other damaging industries such as concrete production (6 million tonnes) and the chemical industry (5.2 million tonnes).2

Soil carbon is stored in both topsoil and subsoil. While we often concentrate on topsoil when discussing soils, subsoil contains stabilised carbon, indicating that both soil systems must be considered. Researchers have stated: “The subsoil has a large influence on ecosystem productivity and the supply of ecosystem services. Carbon stored in subsoils generally contributes to more than half of the total stocks within a soil profile.”3

Soil carbon can be measured as part of any soil tests undertaken but would need to be specifically included

in the suite of requested tests. Results might then inform consideration of how soil carbon could be improved, or decisions about how much carbon would be lost from the site if soils were to be removed.

Healthy soils: key to maximising carbon storage potential

A soil must be in a healthy condition to maximise its carbon storage potential. Key factors are the soil type, texture and structure, as these dictate the soil’s physical and chemical properties. All this impacts a soil’s ability to bind, transport and store nutrients, including organic matter, air and water. In compacted soils, there is insufficient air and water to support healthy decomposition processes, as well as less physical space to store any

2 Building on Soil Sustainability –Principles for Soils in Planning and Construction, Soils Taskforce, 2022

3 Carbon sequestration in the subsoil and the time required to stabilize carbon for climate change mitigation, Carlos A. Sierra, Bernhard Ahrens, Martin A. Bolinder, Maarten C. Braakhekke, Sophie von Fromm, Thomas Kätterer, Zhongkui Luo, Nargish Parvin, Guocheng Wang, January 2024,

Wiley Online Library

2. A prepared tree pit in compacted soil, preventing drainage of water from the pit.

© Birgit Höntzsch. Serene

5

4 https://www.ramsar.

organic matter that may manage to make its way into the soil.

Compacted soils can result in anaerobic soil conditions and limited soil functionality, neither of which are supportive of healthy carbon creation or storage processes in the soil. Compaction also affects a plant’s ability to grow. For example, if a new woodland is planted into compacted soil, tree roots may not develop or may grow very slowly, spreading less wide and deep, with poor above-ground growth too. Over time, this means that much less organic matter both below and above ground is created, thereby substantially impacting the carbon storage potential of that new woodland and the soils beneath it long into the future.

Look after soils: minimise compaction and soil handling

On construction sites, minimising compaction and retaining as much soil as possible in a healthy condition can go a long way to protecting the soil’s carbon storage and processing abilities. This will also ensure its suitability for future planting.

Thoughtful design helps to minimise soil sealing and compaction, for example through early consideration of site-specific soil and leaving areas undisturbed and protected (including in conjunction with tree protection areas and biodiversity

areas). Other considerations are designing levels to achieve a zero cut and fill balance on site, using permeable surfaces, and planning construction access routes and areas with soils in mind.

How soil is stored on a construction site for reuse after stripping will affect its structure, nutrient and organic matter content, and therefore both its carbon content and ability to store carbon in the future. The key is to minimise handling and storage of soils from the outset. Soils that have been stripped and stored should be re-tested and improved if necessary before placing them in their final location. A Soil Management Plan will help to ensure that soil stripping, or cutting, storage and spreading, and fill operations, are carried out in a more sustainable way.

How soils and green and blue infrastructure work together

Soils and green infrastructure (GI) are inextricably linked – there can be no green infrastructure without soils. The type and quality of soils dictates the type and quality of GI, and soils will also dictate the drainage properties and water quality in landscapes and broader developments. This profound interaction influences both the carbon storage potential of soils and the vegetation they will support.

Wetlands as a type of blue infrastructure have significant carbon storage potential if they are designed to act as carbon sinks. They must be able to accumulate large amounts of decomposing plant material so need to be permanently wet and both large and deep enough to allow this to happen.

The Secretary General of the Ramsar Convention on Wetlands, Martha Rojas Urrego, said in 2019: “The science is clear. Wetlands are the most effective carbon sinks on our planet.”4

Landscape architects are ideally placed to raise awareness of the importance of soils with their clients and project teams, and to consider soils in their designs from the start.

The Soils in Planning and Construction Taskforce report, ‘Building on soil sustainability: Principles for soils in planning and construction’5 provides further key facts and figures in relation to soils and development, including guidance on soil surveys and soil management plans.

Birgit Höntzsch is a Chartered Landscape Architect with over 25 years’ experience. Her focus is on green and blue infrastructure delivery to support sustainable development, including climate mitigation, soils, biodiversity and trees. She currently works for Cornwall Council as Portfolio Lead for the emerging Langarth Garden Village.

A strategy for soil

An award-winning development in Cornwall demonstrates a comprehensive approach to the protection of soils with a pioneering Soil Management Plan.

Measures suggested are:

Birgit Höntzsch Dipl-Ing

CMLI

Cornwall Council has embarked on the delivery of Langarth Garden Village – a new community just outside Truro, Cornwall, that will provide 3,800 new homes alongside significant green and blue infrastructure. The masterplan recently won the Royal Town Planning Institute (RTPI) ‘Excellence in Plan Making Practice’ category at the National RTPI Awards and has achieved a Building with Nature Design Award.1

Cornwall Council champions sustainable development in line with its Climate Change Development Plan Document and, as part of this guidance, the Planning Permission includes a high-level Soil Strategy (available for download from the Cornwall Council Planning Portal).2

Langarth Garden Village aims to ensure that the development maximises the reuse of soils and keeps them healthy to support a sustainable future for the community. In addition, soils into landfill must be avoided.

Building on this high-level strategy, the council has developed a Soil Management Plan (SMP) for the Garden Village, setting out principles for the whole site, and additional detail for the first phase of the development. There is a requirement in the SMP for the design of the landscape to seek to minimise carbon loss and maximise opportunities for carbon sequestration within the soils.

– Creation and protection of Soil Protection Zones (SPZs) where the soils and land would not be disturbed

– Minimisation of soil erosion

– Design of habitats that support increased rates of carbon sequestration

– Minimisation of soil handling

– Designing landscape and habitat elements that are permanent (and thus will form a permanent store of carbon)

In practical terms, measures taken at Langarth Garden Village so far include:

– Subsoils from one area of the site that had to be reprofiled have been re-used for construction of a link road and junction where there was a fill deficit

– Topsoil levels in the first phase of parks and infrastructure development have been reviewed, with the aim of increasing depths where possible to retain more soil on-site

– Large wetland areas will be established along the northern site boundary as a component of the drainage strategy, some of which will act as carbon sinks over time

Working with Lancaster University, Cornwall Council is currently contributing to the development of a comprehensive soil policy that will become available as a case study and template for other councils later in 2025.

1 buildingwithnature. org.uk/project-listblog/2022/9/27/ langarth-garden-village

2 Langarth Garden Village Soil Strategy. Available from documents at Cornwall Council Planning Portal PA20/09631, Arcadis for Cornwall Council, Oct 2021

1. A CGI of the wetland landscape proposed at Langarth Garden Village. © Lavigne Lonsdale.

1 https://www.gov.uk/ government/statistics/ uk-waste-data/ukstatistics-on-waste

Elemental soils

A new tool for landscape practitioners, supported by the Landscape Institute, has been launched to help guide decision-making around the climate and nature impacts of projects. Consideration of soils play a key role.

Liz Nicholson

Elemental is a new tool to support the landscape industry design with best outcomes for climate and nature. The tool is designed to support different user groups, from landscape architects to garden designers.

An understanding of soils is essential, from an early stage in the design process, as this will inform everything from plant choice to drainage requirements. The tool broadly considers a range of criteria to help designers manage their use of both topsoil and subsoil in projects:

– Materials usage

Carbon impacts

– The soil itself – Biodiversity

Water relations

Society

Harnessing the multifunctional benefits of healthy soils requires a comprehensive thought process. A key objective must be to retain existing site soils with minimal interventions since soils are a vital storage bank for land-based carbon stocks, and our most effective water storage device to mitigate against flood risk.

Within the soils section, the tool supports designers by guiding them through a series of questions to enable consideration to be given to all impacts as part of the design process. Designers are encouraged to take time to analyse soils, reviewing compaction and evidence of organic matter, and considering the site’s history and potential contamination. In addition, the tool facilitates soil series mapping and, ideally, carrying out soil analysis, including pH, phosphorous, potassium or magnesium.

There are many ways in which designers can minimise their negative impact on soils:

– Since any soil disruption risks the loss of soil organic carbon, and hence negatively impacts climate, Elemental encourages designers to carefully consider their existing topographical situation and promotes minimal intervention.

– Designers are challenged to consider the percentage of soft landscaping and avoid sealing off the surface with hard materials, to maximise aerobic respiration.

– Plants should be specified to be grown peat-free compost and specifiers must encourage nurseries to convert to peat-free growing.

– Prior to projects entering the construction phase, soil management plans are imperative in order to retain soils wherever possible and protect them against compaction.

In the carbon section of the metric, vehicle movements are considered, and many would without doubt be shocked to see how many vehicle movements result from inappropriate soil management. In addition, 57% of UK landfill compriseds soil,1 and Elemental enables us to calculate the carbon cost of this ‘waste’.

As an industry we must ensure that we develop a positive handprint and not a heavy footprint. Early pilot use of the tool has shown that typical garden design projects can take up to 75 years to offset their construction carbon emissions. Initial testing has demonstrated a reduction in carbon emissions exceeding 25%. Elemental will help us to design mindfully, respecting the existing site conditions and working with a lighter touch.

Launched in March 2025, Elemental has been designed, developed and sponsored by the Royal Horticultural Society, British Association of Landscape Industries, Society of Garden Designers, and Landscape Institute.

1. Soil survey with manual Dutch auger, including ‘fizz’ testing for carbonate content using 10% acid solution (HCI).

Rich and fertile: Reconnecting soil, community and landscape

From optimising land use to enhancing community wellbeing, guest editor Noel Farrer argues that soil is fundamental to any site, and the foundation upon

which much

landscape-led thinking should be based.

Noel Farrer FLI PPLI

The accelerated rate of change, driven by technology and access to information, has had an impact upon everything, and landscape is no exception. Almost everything I originally studied, beyond the fundamentals of design, is now out of date and much of it is irrelevant. The key for today’s practitioners is adaptability and continuous learning.

My knowledge and understanding of soils are a case in point. Most of us know that soils are a source of nutrients for growing plants and crops.

We know that healthy soil is important, and with a bit of added manure, it will improve our roses. But on a construction site it too often becomes unwanted muck to be removed so that building work can commence.

Even built environment professionals have a horrifying level of ignorance around soil. Every teaspoon of soil contains around one billion bacteria; every cubic metre of healthy soil captures between 12kg and 35kg of carbon.1 Yet in the construction sector we destroy it and throw it into landfill at a rate of almost 30 million tonnes each year.2

Recently, soil has come to the fore of both our profession and public consciousness. The exhibition at Somerset House in London, Soil: the world at our feet 3 was a mustsee for landscape professionals. “The theme of this startling, enthralling and highly original

©

1 https://www. soilstaskforce.com/ 2Ibid.

3 https://www. somersethouse.org.uk/ whats-on/soil

1. Bailrigg Garden Village, edge treatment.

Farrer Huxley

exhibition is the stuff of life itself –our common ground, our source of food, our overlooked inheritance,” said the Observer 4

Carolin Göhler, the Landscape Institute (LI) president, is currently exploring what ‘landscape-led’ means and how it is used and often abused. There is a simple logic that all construction projects change the landscape; the systems of nature and the disruption caused need to be understood and embraced in the planning and design of whatever is being proposed. Central to development is the disruption and, given present construction practices, often destruction of soils.

Current masterplanning best practice includes the landscape characteristics of topography, water catchment through rivers and streams, aspect, climate, field patterns, urban grain, the impacts of movement corridors, and flora and fauna. Notably absent, and yet perhaps the most important, is soil.

When considering soil as a factor in determining what goes where, it becomes patently clear that this process is not new. Rich or fertile soil has always been deemed to be of high value and where it exists you would never build. Indeed, homes were originally built on poor or rocky land, leading to the shaping of settlements on hillsides, often neighbouring rich alluvial plains. Settling on rocky hilltops was sometimes done for defensive reasons but it was mainly to preserve every patch of rich ground for growing the food necessary for long term habitation.

As a practice, Farrer-Huxley quickly realised the importance of studying existing land use by attempting to be landscape-led in our approach to masterplanning. We recognised the knowledge of local farmers who manage the land and, through them, understood that the value of productive landscapes and their impacts on people needed greater analysis. We have become aware that this is seldom carried out, and that planning policy demands little, if any, scrutiny of land use prior to development.

A simple mapping of soil quality and productivity, highlighting those

with good natural drainage (acquired through farmers’ knowledge) leads to a very different shaping of a masterplan. The nature of soil reflects a broad spectrum of landscape considerations, with many overlapping the spectrum of constraints already recognised in masterplanning. Aspect, gradient, underlying geology, precipitation, and weather patterns all contribute to the unique characteristics of every soil on every piece of land. The nature and role of soil is the basic building block for the consideration of any site and is the foundation upon which much landscape-led thinking is based.

Our work has found that soil mapping through engagement with farmers has created new place characteristics that are both healthier and more dynamic. The resulting masterplans accommodate multiple and diverse uses and, perhaps most importantly, lead to the development of places that are truly distinctive. The mapping of soil as a basis for landscape-led masterplanning does not limit opportunities; in fact, it is a methodology that shapes the

Soils Task Force

Farrer Huxley, working with JTP and others, including Lancaster City Council and Lancaster University, set up the Soils Task Force5 to better promote how we can practically support the preservation of soils in construction. It also recognises that soil is fundamental to the landscape, and the landscape of every place must determine the changes we make. The work at Bailrigg and the Soils Task Force has attracted others who are working to promote best practice regarding soil, not least the work of Birgit Höntzsch in Cornwall (see pp28–32). Lancaster Council, in a partnership with Cornwall Council, have supported the work of the Soils Task Force5 and invested time through their enlightened planning teams to explore the necessary changes that need to be made to

A

simple mapping of soil quality and productivity, highlighting those with good natural drainage (acquired through farmers’

knowledge) leads to a very different shaping of a masterplan.

healthiest and most responsible approach. It is suitable for urban extensions, housing and mixed communities, as well as infrastructure and commercial sites.

The LI Award-winning masterplan developed for Bailrigg Garden Village (see case study on page 41), for which a multidisciplinary team

the planning system. Through this approach, in future there should be better recognition of the importance of soils in the planning process.

soilstaskforce.com

4

including Farrer-Huxley worked with the soils department at Lancaster University, triggered our awareness and understanding of soil. This led to a deeper understanding of which habitats would thrive in each location and consequently the infrastructure and housing being laid out to best support a thriving and productive place. There were of course constraints: the high-voltage cables were to remain where they were; existing settlements were worked around; and both railways and canals severed the site’s natural systems. Ultimately, however, we felt the plan that emerged was a truly landscape-led proposition, as it started with the question; what future functions best align with the natural attributes of the site? The subsequent process identified and guided the locations of the required new homes and urban centres within the plan. These new places, shaped by the characteristics of the landscape, became more individual and distinct. This awareness of the importance of the preservation of soil has driven my practice to a better understanding of landscape-led design. We are

aware that a new residential project does not start with the needs of the housing but with the soil. Only through understanding the capacity for landscape improvement can we best accommodate the outcomes required. A new development, if it is a proposal that is considerate of soil, will deliver not only distinctive housing but also a diverse range of land uses, associated employment, and healthier future communities. This more environmentally sensitive approach does not necessarily increase costs and can certainly speed

up the planning process as it is one that will garner greater support from neighbouring communities, whether human or other!

The relationship between people and soil is the topic of considerable research around environmental generational amnesia (EGA). Currently, society lacks the understanding of the soil, land management, and environment that is required to sustain agricultural practices. The creation of suburbia over recent generations, as dedicated places in which to live, connected by cars, has caused us to

The relationship between people and soil is the topic of considerable research around environmental generational amnesia (EGA). Currently, society lacks the understanding understanding of the soil, land management, and environment that is required to sustain agricultural practices.

2. Restoring people’s connection with the land.

© Farrer Huxley

2.

forget about nature as our relationship with land has fallen away. EGA has come to be recognised as a result of our understanding that working with soil and growing plants is a therapeutic activity that aids mental health. Many of life’s anxieties that derive from our modern suburban life and resulting EGA can be addressed by greater proximity with natural systems. Landscape-led masterplans that deliver integrated places, where working the soil and production of food sit alongside other elements of placemaking, are a fundamental requirement of future healthy life.

Our need and craving for soil and cultivation is evident in many places. When a skip garden and natural swimming pond occupied meanwhile

spaces during construction of the emerging King ’s Cross development, these spaces were overwhelmingly popular, with people flocking to them. The final plan, with these meanwhile spaces removed, is now sanitised and has lost the magic that was clearly addressing societal EGA.

During our work at Bailrigg Garden Village, early consultation revealed the crisis faced by farmers and precipitated by EGA that now jeopardises future land management, especially near residential areas. Insights into EGA highlight the crucial need to restore people’s connection with the soil if we’re to create healthy future communities and economically viable new places.

Understanding soil and landscape is a step towards an awareness of the intrinsic connection between us and nature. This alone will improve the health of individuals and inform the health of the future places in which we exist and will hopefully also help to create.

Noel Farrer FLI PPLI is Past President of the Landscape Institute, Director of Farrer Huxley Landscape Architects and a member of the Soils in Planning and Construction Task Force

3. Bailrigg Garden Village, edge treatment.

© Farrer Huxley

Soil and landscape-led design: key takeaways for practitioners

Considerable work is required across the construction sector to promote the importance and value of soil. As well as planners and engineers, we in the landscape profession must recognise our role in preserving soil, not only for carbon capture but in recognition of its fundamental role in the life cycles of all living things. Perhaps even more importantly, we must recognise that we cannot replace living soil easily or rapidly.

Key takeaways for practitioners undertaking early site appraisals prior to design and masterplanning:

– Make a more in-depth analysis of the existing site that includes the quality and distinctions in the soils and underlying geology

– Understand present land use and the associated constraints by speaking with the current farmers and land managers

– Generate an outline plan which best benefits landscape outcomes, aspect, food growing, appropriate natural habitats including wood and forest, and water movement

– Consider where the movement corridors and built environment can co-exist alongside the identified landscape outcomes

– Consider the future stewardship and management of the landscape to ensure the infrastructure supports future land-based outcomes

– Review your own and your practice’s standard approaches to soil at every stage of design and delivery

– Promote the value of soil and ‘landscape-led’ design to clients.

– Adopt and promote best practice to design teams and fellow professionals in planning and engineering

4. The complex landscape provides a wide range of soils, all of which need consideration during masterplanning.

© Farrer Huxley

4.

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Soil-led masterplanning

An innovative soils-led approach to masterplanning aims to change the scale and pattern of future residential development.

Farrer Huxley, in collaboration with JTP Architects, has developed a spatial masterplan framework for Bailrigg Garden Village in Lancashire. Through comprehensive community engagement over RIBA Stages 1–2, the project sought to redefine landscape-led masterplanning for the 550-hectare site. Alongside the delivery of 5,000–8,000 new homes, the team explored how a landscape in crisis might be restored to resolve its current challenges and meet the demands of future living.

An innovative approach to the land, based on in-depth site mapping and analysis of its qualities, processes, and stewardship, was kindled by Lancaster University’s soils team and the local consultation process.

There is a societal lack of understanding about the environment needed to sustain agricultural practices: now identified as environmental generational amnesia (EGA). Early consultation revealed the crisis farmers face due to EGA jeopardising future land management. Hence the masterplan for Bailrigg Garden Village aims to create a balanced and enduring local economy through the reconnection of the future community with the soils and landscape.

The masterplan was shaped by the quality of soils, creating patterns of development that reflect the landscape’s natural characteristics. Early mapping of soil quality informed land use allocation, with productive landscapes and their associated enterprises integrated into the new neighbourhoods. Understanding the processes that shaped past settlements, food production, employment, and stewardship informed the development of a balanced system for people, industry, food production, and nature. This varied, smaller-scale mosaic of land uses includes regenerative farming, open space for leisure, a network of green routes for walking and cycling, and areas left untouched for rewilding. The result is a new settlement that conforms to the natural rules of the place, where the form and density of its components contribute to the same ecosystem.

Green infrastructure makes up approximately 70% of the land, and 70% of that green infrastructure is productive. The proximity to homes and workplaces of green spaces, orchards, and areas for growing ensures everyone is in touch with nature and the natural cycles that impact them. The common language of food – growing, making, selling, and eating – binds local communities and creates healthy local and circular economies.

The success of the place will be dependent upon individuals understanding their contributions, whether through buying local produce, working in local food businesses (such as a brewery), or engaging in traditional land management (crops, forestry, livestock). Long-term success will be assessed through collaboration with Lancaster University – from EGA to biodiversity, carbon, climate change resilience, and community wellbeing. This critical analysis will inform future phases of development.

Bailrigg Garden Village was the winner of the Excellence in Masterplanning & Urban Design category at the Landscape Institute Awards 2022.

1. Bailrigg Garden Village, illustrative masterplan.

1. Noel Farrer FLI PPLI

Soil systems

Collaboration is key for making best use of challenging soil conditions. LI Award-winner, Mayfield Park, highlights the need for a landscape-led approach to guide decision-making and inform progress.

Max Aughton

Designed by Studio Egret West (SEW), Mayfield Park is a new 6.5-acre park on a former industrial site just minutes from Manchester’s Piccadilly railway station. It is the first new public park to be built in the city centre in over 100 years, and consists of a new green space with the restored River Medlock flowing through its core. The park is the jewel in the crown of the transformational £1.4 billion Mayfield development.

Delivered for the Mayfield Partnership, Civic Engineers led the contractor team for PP O’Connor through RIBA Work Stages 5 and 6. The collaboration between engineers, the landscape architect, and the soil scientist played a crucial role in solving the complex challenges presented by a site with a 300-year history of environmental neglect and industrial damage.

Lying derelict for over 30 years, the site has been repurposed into a public green space that celebrates the heritage of the area and exemplifies sustainable construction practices. Following demolition of the existing structures, the site was levelled and enabling works undertaken. This included the reuse of approximately 9,000m3 of ‘made ground’ soils – natural soils that have been largely replaced by man-made materials. The ground remediation strategy, originally developed by ROC and overseen and implemented by Buro Happold, was carried out through a separate construction contract that preceded

the main park works. This process allowed much of the site-won material to be reused for landform and footpath bases.

For those areas designated for planting, a different approach was needed. Testing by Tim O’Hare Associates (TOHA), confirmed that the volume and quality of substrate extracted from the site-won material was insufficient and too diluted to withdraw from the bulk excavation.

SEW collaborated with TOHA to create a range of imported topsoils, subsoils, and sands, developing bespoke soil profiles tailored to support a variety of planting types, habitats, and specific tree pit needs (read more from Tim O’Hare about manufactured soils on page 54).

The Mayfield Park development has demonstrated that, even in an urban environment with a rich industrial history, a landscape-led approach can realise real benefits in terms of optimising soil reuse, carbon reduction, biodiversity, and climate resilient drainage design.

Critical to the implementation of this approach on projects such as Mayfield is the understanding that the environment functions as a single system and that the soil beneath our feet is central to how all these functions interact. An early understanding of the landscape, soil, and ground conditions is critical to maximising opportunities and creating spaces where people can lead happier and healthier lives.

Max Aughton is a Project Landscape Architect at Studio Egret West

1. The existing ‘made ground’ at Mayfield was used to build structural elements such as pathways, with imported soils used for planting areas. © Richard Bloom

Contamination and remediation

Soil contamination requires a multidisciplinary approach and a willingness to explore innovative techniques to address both current and future challenges.

1. Aerial view of abandoned copper mine.

© Ashley Hampson

Elizabeth Beers

MIEnvSc CEnv AMICE

Soil: generally taken for granted, yet such a precious asset that requires significant effort to protect from contamination and negative human influence. As an environmental consultant, I have spent almost two decades attempting to understand and address soil contamination. This is a multifaceted and critical issue that impacts our ecosystems, our health, and our efforts towards sustainable development.

Sources

of soil contamination

Where does soil contamination come from? Contamination types have changed over time and encompass a wide variety of pollutants: pesticides and herbicides used in agricultural practices; the introduction of large quantities of heavy metals and chemicals into soils during the Industrial Revolution; an accumulation of high concentrations of naturally occurring substances such as metals;

the widespread use of synthetic chemicals; and those arising from mine workings, urbanisation, and improper waste management and disposal. Emerging contaminants, such as PFAS (per- and polyfluoroalkyl substances, or ‘forever chemicals’ as they are often called) and microplastics are revealed all the time, as our lifestyles change and new technologies are developed. Each contaminant requires a thorough understanding of its provenance, management, and mitigation options. Additionally, every site may have a unique mix of contaminants associated with its use and history. It is worth mentioning that some chemicals and materials were once considered safe (for example asbestos) but scientific advancement has since disproven this and exposed the extent of potential harm. In the UK, as a relatively small country formed of islands, there are few places that haven’t been influenced by the people who have colonised and lived here, so virgin soils are limited.

This article focuses on contamination in soil, but consideration is also given to the impact on the water environment, including contamination of soil leachate, groundwater, and surface water.

Consequences

Contaminated soil disrupts natural ecosystems by affecting the health and diversity of soil organisms. Microorganisms, fungi, and plants play crucial roles in maintaining soil structure and fertility. Contaminants can inhibit their growth and function, leading to reduced soil productivity and altered nutrient cycles. Contaminated soil also directly impacts the safety of our food crops since plants can absorb harmful chemicals from the soil, which then enter the food chain and pose risks to human and animal health. This is particularly concerning for communities that rely on locally grown produce for their sustenance.

Exposure to contaminated soil arises through direct contact, inhalation of dust, or consumption of contaminated food and water. Associated health risks include respiratory problems, skin irritations, neurological disorders, and an increased risk of cancers. Vulnerable populations, such as children and the elderly, are particularly at risk and assessment of contamination should take into account the sensitivity of the environment, inhabitants and visitors. Soil contamination can have far-reaching consequences for our environment and health.

How do we decide whether land is contaminated or not?

At this point, it is pertinent to distinguish between land contamination (land that may be affected) and contaminated land (when harm has been proven or there is the significant possibility of significant harm to either human health or controlled waters); as defined by Part 2a of the Environmental Protection Act 1990.1

For Part 2a, an assessment of the potential for harm should be undertaken where contaminants are present. An equivalent assessment for pollution is undertaken for controlled waters. In both scenarios, consideration should be given to potential sources of contamination, pathways, and receptors so that a viable pollutant linkage may be identified between all three components.

1 https://assets. publishing.service. gov.uk/government/ uploads/system/ uploads/attachment_ data/file/223705/ pb13735cont-landguidance.pdf

2. Hexavalent chromium contamination. © Elizabeth Beers

2 https://www. legislation.gov.uk/ uksi/2015/810/contents

3 https://www.gov. uk/government/ publications/landcontamination-riskmanagement-lcrm

Contamination assessment

Assessment of contamination may be undertaken for a variety of reasons, such as:

– Managing existing issues, perhaps associated with the site’s history

– Dealing with new pollution events, for example spills and leaks

– To determine liability

– In support of a planning application for redevelopment or to comply with building regulations

– At the instigation of regulating authorities, for example under Part 2a of the Environmental Protection Act 1990 or Environmental Damage (Prevention and Remediation) Regulations2 (EDR)

– For voluntary action to remediate a site or situation

Conducting a thorough assessment and quantifying risk is crucial to understanding the land. The assessment generally requires the identification of the types and extent of contamination and unacceptable risks through the development of a Conceptual Site Model (CSM). The CSM guides further investigations and evaluates potential sources of contamination, their severity, and how they may behave with available exposure pathways (routes) to something that could be affected, known as a receptor. If a complete pollutant linkage, with a viable source, pathway, and receptor, is identified, this is usually the point at which consideration is given to further investigation and assessment, with the potential for subsequent remediation or mitigation.

In the UK, we have the Land Contamination Risk Management (LCRM) guidance,3 which is advocated as an iterative and phased process to capture sufficient contamination information. This enables a robust assessment of risks and the provision of a scheme for their remediation and mitigation.

Regulatory compliance, ensuring that all activities comply with local, regional and national regulations, is vital and can entail obtaining necessary permits and adherence to environmental standards. The effectiveness of soil contamination management depends on the

3. A maintenance shed with roof removed.

© Elizabeth Beers

4. Removal of underground tank.

© Elizabeth Beers

regulatory framework in place: policies and regulations must be strict enough to prevent contamination and ensure proper remediation of contaminated sites. However, inconsistencies in regulations across regions can complicate efforts to address soil contamination on a global scale.

Challenges in soil contamination management

The challenges of managing soil contamination, from identifying contamination sources to implementing effective remediation strategies, are numerous.

Selecting the appropriate remediation techniques is crucial for successful soil contamination management. LCRM includes an options appraisal to assess the suitability of the site to minimise or remedy the effects of the identified risks. Traditional methods, including soil excavation and landfilling, can be disruptive and costly and are not finite solutions. Innovative approaches, such as bioremediation, phytoremediation, and soil washing offer more sustainable alternatives but require further research and development to optimise their efficacy.

An effective remediation strategy should be tailored to the specific conditions of the site and requires the selection of appropriate technologies. The feasibility, cost, and potential impact of each option must be considered in addition to a sustainability cost-benefit appraisal.

The Sustainable Remediation Forum UK (SuRF UK)4 is an initiative to evolve sustainable land management and remediation. Remediation activities themselves can sometimes cause environmental disturbances and unintended consequences that must be carefully managed. Hence it is often difficult to design a one-sizefits-all remediation plan. Consideration should also be given to both the potential effects of climate change and the use of chemical or biological additives to soil and groundwater that may treat specific contaminants but have uncertain longevity. In some circumstances, synergies between treatment and development may be exploited, such as stabilisation and

solidification, where contaminants in the soil matrix are treated and the soil is consequently geotechnically improved.

Remediating contaminated soil often involves significant financial investment. The costs associated with site assessment, remediation technologies, and long-term monitoring can be prohibitive, particularly for developing countries and small-scale industries. Balancing economic feasibility with environmental protection is a persistent challenge.

Plans for the future

Continued research and the development of innovative remediation technologies are crucial to the sustainable treatment of soil contamination. Collaborative efforts between academia, industry, and government can accelerate the advancement and deployment of effective remediation methods. In the UK there are several professional bodies that further the efforts of those working in industry and produce a wide range of supporting documents and resources for sustainable development. The Remediation Society5 (RemSoc) is one such group, established by a group of professionals and practitioners working in the remediation sector and focused on addressing related environmental challenges.

RemSoc aims to promote best practice, share knowledge, and drive innovation in land regeneration

through collaboration with like-minded organisations.

The focus of RemSoc’s 2024 conference was ‘Rethinking Remediation’ and its aim was to explore alternatives to engineered or chemical technologies for contaminated soils. We were fortunate to be joined by eminent professionals for a discussion around soil science and the Reconstructed Soils from Waste Project.6 This considered the potential for nature-based solutions to balance the needs of carbon mitigation, biodiversity, flood management, and water supply.

Conclusion

Soil contamination presents a complex and multifaceted challenge that requires coordinated efforts from many stakeholders. By understanding the sources, impacts, and management strategies associated with soil contamination, we can develop effective solutions to protect our environment and ensure the wellbeing of future generations. It is our responsibility to advocate for sustainable practices and contribute to the global efforts in combating soil contamination.

Elizabeth Beers is a Chartered Environmentalist with over 18 years’ experience in land contamination, geotechnics, and remediation. She is the current Chair of the Remediation Society and Regional Director for Ground and Water at WSP in the UK.

4 https://claire.co.uk/ projects-and-initiatives/ surf-uk

5 https://www.remsoc. org/

6 https://claire.co.uk/ projects-and-initiatives/ recon-soil

5.

5. Hydrocarbon wash-off from manufacturing site.

© Elizabeth Beers

From coal mine to upland hay meadow

Remediating a former open cast coal site is a complex process, which shines a light on the need for greater recognition of soil when considering Biodiversity Net Gain and ongoing management and monitoring.

The effective restoration of any former mineral site can only be achieved if there is an available soil source on site. Depending upon the type of mineral activity, this resource may be very variable. Sadly, it is often the case that soils are not treated with the same qualitative measures as other ecological assets but, without them, nature conservation objectives will not be fully met. Biodiversity Net Gain guidance, as currently drafted, gives little weight to the presence or absence of soils or soil types. This is unfortunate because it’s this information that will ultimately determine the most appropriate habitat type to be provided. Hopefully future updates of BNG guidance will address this issue to ensure that appropriate weight is given to soil type in site restoration.

Halton Lea Gate is a former open cast coal site situated on the Cumbria-Northumberland border. The site was worked for open cast coal, but the operator went into administration in 2020. Consequently, the site was left in a partially worked, partially restored state. House Associates was employed by the administrator to invoke the restoration bond with Northumberland County Council.

Working closely with the County Council Minerals Planning Officer, a revised restoration scheme was drawn up to create a mosaic of grassland habitats to complement the nearby RSPB reserve at Geltsdale.

Prior to the commencement of the open cast coal working, the site was stripped of topsoil, which was stored along the periphery of the site. The principal restoration objective for the site was to recreate traditional upland hay meadow. In these areas, a minimum of 250mm of topsoil was placed over regraded shales and subsoils. These were then seeded in late spring and early summer, ensuring a successful germination by early autumn. There were insufficient soils available to achieve a 250mm depth over the entire site, so areas of rough grassland were created on the steeper slopes and adjacent to retained wetland areas, requiring soil cover of only 100–150 mm.

Other areas within the site with rocky substrata were loose tipped with a minimal cover (50mm) of soil. These areas were left unseeded to allow natural regeneration to take place. By providing this matrix of managed rough grassland and wet grassland, it is hoped that local upland waders such as curlews can continue to thrive.

A Landscape and Ecological Management Plan was drawn up for the site to ensure that regular monitoring takes place. It is often the case that soils are forgotten in these plans, but post-restoration soil surveys are extremely helpful in determining how rapidly soils recover and the overall soil health. Monitoring will inform learnings that can be applied to other sites.

Chris House is Director of House Associates and Chair of the new Landscape Institute Education and Careers Committee

Chris House

Regeneration game

National Trust Soil Consultant, Felicity Roos, argues that a holistic approach to soil management across both rural and urban areas is vital in the face of climate change and biodiversity loss.

“Despite all our accomplishments, we owe our existence to a six-inch layer of topsoil and the fact that it rains.” – Paul Harvey1

Healthy soils deliver the ecosystem services that enable life on earth. Soil filters and regulates the discharge of rainwater to prevent flooding; it is capable of storing large amounts of carbon and other greenhouse gases (GHG) that help to regulate climate; it buffers against pollutants, thus protecting air and water quality; and it provides us with essential construction and manufacturing materials. Around 95% of our food (nearer 99% if you are vegan) is grown in soil.2 We drink

coffee, grown in soil, from a cup that is essentially baked soil (clay).

Soils are also one of the main global reservoirs of biodiversity, with 59% of living organisms in terrestrial ecosystems spending some, or all, of their life in the soil.3 This makes it one of the most important and biodiverse habitats on earth – about which we know the least.

However, as for all other pools of biodiversity, soil biodiversity is at risk through loss of habitat, with

1 https://en.wikipedia. org/wiki/So_God_ Made_a_Farmer

2 Ellis, H., (2025) Is the source of 95 percent of our food in trouble? Retrieved from: Is the source of 95 percent of our food in trouble?BBC Food

3 Anthony, A.A., Franz Bender, S., van der Heijden, M. G. A. (2023) Enumerating soil biodiversity. Proc. Natl. Acad. Sci. USA 120 (33)

Felicity Roos

1. Cattle grazing at Holnicote Estate, Somerset. © National Trust Images/ Nick Upton

© National Trust

3. Cattle grazing

©National Trust Images/ Nick Upton

around 33% of soils globally now seriously degraded, and significantly more in poor condition.4 In 2015 it was estimated that soil degradation costs the UK around £1.2 billion every year.5 This is critical, not only for food production but because it is the soil biology that drives and enables the related ecosystem services that we rely on.

4 FAO and ITPS (2015) Status of the World’s Soil Resources (SWSR)

– Technical Summary Food and Agriculture Organization of the United Nations and Intergovernmental Technical Panel on Soils, Rome, Italy. Retrieved from: Status of the World’s Soil Resources - Technical Summary

5 Graves, A.R., et al. (2015) The total costs of soil degradation in England & Wales. Ecological Economics, 119, 399–413

6 Cranfield University 2025. The Soils Guide. Retrieved from LandIS - Land Information System - Series  Cranfield University, UK

7 Lal, R. (2004) Soil carbon sequestration impacts on global climate change and food security. Science 304,1623–1627

Healthy soils are central to enabling the National Trust to deliver its ambitious objectives for people and nature, so that it can be here for everyone, for ever. We need healthy and resilient soils to help mitigate the impacts of climate change, with its inherent risk of increased floods and droughts, and to provide habitats for nature to thrive. The Trust’s gardens and property teams have a vital role to play to improve soil quality on the land we manage in-hand, but we also recognise how important it is to work with farm tenants to improve soil health. This, in turn, can help slow the flow of water across land in times of flood, and hold water in the landscape in times of drought.

Soil, at its most basic level, is a porous material that is made up of varying proportions of sand, silt, clay, and organic matter. The differing proportions give different soils their

distinct characteristics as peats, sands, podzols, and more, with over 700 individual soil types recognised in the UK.6 Large areas of Scotland and upland areas are dominated by peaty, thin, acidic soils that support open scrubby vegetation dominated by heather and mosses; lowland, nutrient-poor, sandy soils give us bracken heaths; and rich alluvial flood plains support species-rich meadows. The distinct properties of soils shape the habitats above them and each has its own unique biodiversity.

These sand, silt and clay particles give a soil many of its physical properties, but it is the soil organic matter that is critical for soil health as it supports and feeds the soil’s

biology, and it is often this fraction of soil that has been most degraded. Soil degradation and the loss of carbon (organic matter) from soil began with the advent of agriculture over 7,000 years ago, with the global loss of soil carbon since 1850 estimated at around 66 gigatons (±12), mainly caused by land use change7 that began with the mechanisation of agriculture after the Second World War. The exportation of European methods of agriculture to other parts of the world, with very different climates and vulnerable soils, has accelerated the global rate of soil carbon loss and degradation. This global decline in soil quality is now being compounded by climate change and pollution, with micro- and

2.

3.

2. The farmer and his dog by a hedge on Low Sizergh Farm, Kendal, Cumbria.

Images/David Levenson

at Holnicote Estate, Somerset.

nanoplastics and ‘forever chemicals’ emerging as significant global concerns.8,9

In an undisturbed natural system, the soil organic carbon pool is in equilibrium, with seasonal losses and gains in balance. Any disturbance to that system – a forest fire, digging by animals, or ploughing to plant crops – causes disruption that results in losses in soil carbon. Soils are highly resilient and can survive short-term shocks, but they struggle to recover from continued disturbance such as annual ploughing and other agricultural activities.

The diversity of soil types means there is no one-size-fits-all answer to sustainable soil management, hence actions need to be tailored to location, land use, and soil type. This is where movements like regenerative agriculture (Regen Ag), agro-ecological farming, and nature-friendly farming have much to offer.

Regen Ag holds, at its core, “the intention to improve the health of soil or to restore highly degraded soil,

which symbiotically enhances the quality of water, vegetation and landproductivity”.10 It isn’t constrained by the prescriptive limitations that exist in some other agricultural models, such as organic farming. This means that practitioners are able to choose the practices that best suit their soils and systems. However, the lack of

definition around what ‘regenerative’ means is one of the main criticisms of the movement11 since it is hard to define whether a farm is ‘regenerative’ or not.

Shifting a farm from ‘traditional’ practices to nature-friendly farming or regenerative agriculture is not necessarily a simple transition. It might

Principles of good soil management followed by Regen Ag:

1. Minimise disturbance (physical and chemical)

2 Protect and cover the soil at all times (with living plants or mulch)

3. Maintain living roots

4. Encourage a diversity of plants, to help feed a diverse soil biology

5. Integrate animals, be that livestock or nature, to help drive ecosystem services

(Adapted from Dirt to Soil by Gabe Brown12)

4. Rosy bonnet (Mycena rosea) mushrooms at Sheringham Park, Norfolk.

© National Trust Images/Rob Coleman

8 Chang, N., et al. (2024) Unveiling the impacts of microplastic pollution on soil health: A comprehensive review. Science of The Total Environment, 951

9 Mahinroosta, R., Senevirathna, L. (2020) A review of the emerging treatment technologies for PFAS contaminated soils. Journal of Environmental Management, 255, 109896

10 Rhodes, C.J. (2017) The imperative for regenerative agriculture. Sci. Prog., 100, 80–129.

11 Newton, P., et al. (2020) What is Regenerative Agriculture? A Review of Scholar and Practitioner Definitions Based on Processes and Outcomes. Front. Sustain. Food Sys, 4,

require investment in new equipment that can be a large barrier to farmers currently facing financial pressures. But one of the greatest challenges is that it can require a significant paradigm shift in attitudes towards land management. Currently, many land management decisions are influenced by a Victorian attitude of ‘taming nature’ and

making everything neat. Farmers and landowners are sometimes reluctant to let their hedges grow out to benefit nature, because they have always held the belief that a neat hedge is ‘right’ and they worry about being judged as poor farmers for having ‘messy hedges’. It’s a similar problem in urban areas where many homeowners like neat gardens, and they expect the council to keep grass on verges and in communal areas mown short, with weeds sprayed, which removes vital habitat and food for insects and birds.

We need a shift towards a more holistic landsharing model of land management, with well-managed soils and room for nature around both housing and food production.

We need a shift towards a more holistic land-sharing model of land management, with well-managed soils and room for nature around both housing and food production. This will require a social science-informed campaign to change people’s attitudes towards what good management looks like in both urban and rural areas. A lack of knowledge need not be a barrier to change. We now need to inspire and empower people to act.

Returning to soil, we understand both the principles and practice of good soil management, yet adoption has been slow despite work by many

organisations such as the National Institute of Agricultural Botany and the farming press. Government subsidies such as the Environmental Land Management scheme in England are also leading to positive change. Restoring soil plays a critical role both in mitigating the impacts of climate change and restoring nature. Sequestering a fraction of the soil carbon we have lost will help reduce annual GHG emissions. We must continue to advocate for the importance of soil health and the many benefits it can offer to the farming community, nature, and society. We need that message to be universal and to come from multiple sources.

Felicity Roos is National Consultant – Soil at the National Trust. She is interested in the role of regenerative agriculture and holistic land management in combating climate change and restoring the environment.

5. Property manager and advisor from the Department of Agriculture carrying out a farm audit at Bally Quintin Farm in Northern Ireland.

© National Trust Images/ Joe Cornish

5.

Soil capital

A pioneering Environmental Land Management scheme is using National Character Area profiles as a basis for sustainable food production and business planning.

The Department for Environment, Food & Rural Affairs has made a considerable investment into the farming community to engage them in the design of the new options under the Environmental Land Management (ELM) scheme. Many of these options reposition food production on a more sustainable basis, with a strong emphasis given to soil health.

As we move closer to developing a Land Use Framework for England, it is essential that we focus on the health of our soils. Arguably the most important infrastructure we have, soils have been largely ignored for far too long by the planning system.

As landscape professionals, the elements of natural capital – air, water, soils, ecosystems, and micro-climate – are the tools of our trade. We have a special professional responsibility to ensure the health of these elements before even considering the policy or design process. Our mapping of National Character Areas (NCAs) assesses the diversity of natural capital assets and records the results of human intervention on our soils and ecosystems over thousands of years

The ELM Convenor project in Hampshire is one of five national pilots exploring a new system of governance of land management. The project made use of the NCA profiles as a way of mapping soils, micro-climate and ecosystems – to set the baseline for agenda-setting and business planning. Today we are only just beginning to realise the huge damage caused to natural capital by the way we have produced

our food. This includes the pollution of our drinking water, excessive greenhouse gas (GHG) emissions, and the destruction of ecosystems. In our study, the value of food production was set at £110 million a year but the cost of that food production, when we included the cost of the unintended consequences, was £126 million for GHG emissions and drinking water purification alone.

In contrast, we were able to demonstrate through our research that it is perfectly possible to produce food sustainably, to reverse the drivers of climate change, and restore nature through the careful management of soils. The Cholderton Estate on the HampshireWiltshire border is one example of hundreds of farms that are actively involved in the current revolution within the farming industry. Cholderton sequesters 128 tonnes of carbon per hectare – double that of similar neighbouring, chalk soil-based farms. The soil fixes nitrogen from the atmosphere for enhanced fertility, and produces organic food from both arable and pasture, as well as clean water and air, in a landscape that teems with wildlife. We estimate the estate will be carbon neutral for the next 50 years.

Merrick Denton-Thompson FLI is Past President of the Landscape Institute and a Founding Trustee of Learning Through Landscapes. For more detail about the ELM Convenor pilot, visit lex.landscaperesearch.org/content/ farming-in-hampshire-national-pilot. For access to the reports, contact mhdt@btinternet.com.

Merrick Denton-Thompson FLI

Left: Map of the 10 NCAs across Hampshire – from draft introductory information for consultation.

© Environment Systems

Right: Value of benefits by each NCA. © terra firma

Transforming Yorkshire’s uplands

Restoring peat and building resilience through natural flood management

reducing wildfire risk (critical in a warming climate), providing a more suitable habitat for breeding moorland birds, and reducing flood risk.

As the impacts of climate change reshape landscapes globally, Yorkshire’s uplands are becoming a testing ground for innovative ecological strategies

Working across 5,500 hectares of West Yorkshire, the Landscapes for Water partnership between the National Trust and Yorkshire Water has embraced a multi faceted approach to climate resilience. Between 2023 and 2028, our pioneering initiative is planting 300,000 native trees and installing 3,500 leaky dams, with positive implications for biodiversity, carbon storage, and flood mitigation.

Reimagining resilient landscapes

Many South Pennine uplands have been degraded by industrial pollution, overgrazing and fires, which have created areas of dry and exposed peat. When peat is dry, its ability to capture and store carbon from the atmosphere is reduced, and degraded moorland peat can therefore lead to an increase in carbon dioxide and other greenhouse gases being emitted into the air.

The dried-out peat also increases the likelihood of flooding downstream as the water flows over the hardened surface instead of being absorbed. Leaky dams – constructed from stone, willow, and turf – form a complementary intervention. Designed to slow water flow and retain moisture on the uplands, they mitigate downstream flooding while simultaneously rejuvenating degraded moorland. Creating wetter conditions aims to decrease the dominance of invasive purple moor grass, and instead allows peat-forming plant species such as sphagnum moss and cotton grass to grow. Sphagnum moss can hold 20 times its weight in water, so it has multiple benefits such as creating new peat,

With support from the Lottery-funded Calderdale Sphagnum Project, Rangers at Marsden Moor estate have established their own moorland plant nursery. Here, sphagnum moss and cotton grass are grown and planted out onto the moor alongside a diverse mix of native trees, with the help of the local community and volunteers.

Close collaboration with tenants and commoners has been pivotal. While some initially hesitated, many embraced the project after bespoke land management strategies were developed to align tree planting with commercial interests and Higher Level Stewardship obligations.

The project’s long-term success hinges on continued collaboration, strategic funding, and adaptive management. Support from the West Yorkshire Combined Authority and the Trees for Climate grant programme underpins its viability. Moreover, these efforts contribute more broadly to the White Rose Forest, a visionary initiative that is transforming the region’s green infrastructure.

Reflecting on year one

While the scope of the Landscapes for Water programme is vast, its early achievements offer a compelling glimpse of what’s possible when ecological stewardship meets community action. As Yorkshire’s uplands transform, the project serves as a model for other regions grappling with the challenges of a changing climate.

Jess Yorke is Land, Outdoors and Nature Project Manager at the National Trust. Carol Prenton is Land and Property Surveyor at Yorkshire Water.

Jess Yorke, Carol Prenton

1. A diverse mix of native trees is used to slow the flow of water and restore the peat.

Manufactured soils: A user guide

The role of manufactured soils has evolved and expanded hugely over the last few decades to keep up with the imagination and expectations of landscape designers, and especially those working in the urban realm. We expect trees to grow happily in pavements, parks to exist on top of Tube stations and car parks,

A comprehensive understanding of soils is required throughout the entire design team to ensure appropriate soils are specified to support healthy plant growth and development.

a garden to flourish on the 10th storey of a building, runoff from roads to flow into and be absorbed by planting beds, and grass lawns to withstand the trampling of millions of pedestrians each year. The soils used to support these challenging landscapes must possess specific properties to meet these demands.

What is a manufactured soil?

Manufactured soil is the widely used term to describe a soil medium that has been created when two or more materials are blended. Other terms, such as soil substitute, man-made growing media, engineered soil, and artificial substrate have also been used over the years, but manufactured soil seems to have now stuck.

Tim O’Hare

1.

1. Lightweight manufactured soil profile. © Tim O’Hare

In many respects this process is simply a fast-track version of the natural soil-forming process (pedogenesis), whereby soil is formed by the interaction of parent material, topography, climate, and organisms over a long period of time.

The materials used to make a manufactured soil usually consist of two components: inert, mineralbased media (such as subsoil, sands, crushed rock, demolition arisings, soil washings or quarry overburden); and bulky organic ameliorants (such as green compost, spent mushroom compost, composted bark fines, or even natural, as-dug, topsoil). These may be combined with other specific additives where more specialist enduse or targeted functions are required – for example, lightweight media, aggregates, soil conditioners, biochar, and lime.

As the name suggests, the materials are often blended ex situ at dedicated sites using a range of industrial-sized soil processing machinery and equipment such as excavators, loading shovels, screeners, hoppers, and conveyors. Alternatively, it is possible to manufacture the soil in situ at the site using large agricultural machinery to spread and blend the materials on the ground before planting directly into the mix.

The history of manufactured soils

Manufactured soils have been used in the UK commercial landscape industry since the mid-1990s. Before then, the choice of soils for new urban landscape projects was either natural topsoils and subsoils imported from nearby greenfield developments where they were surplus to requirement, or ‘skip waste’ soils. These were the soil fines collected after the contents of skips and other site clearance operations had been screened. They were usually highly alkaline, saline, low in organic matter and plant nutrients, and often contained various sharps (glass, nails, ceramic tile) and chemical contaminants (heavy metals, hydrocarbons, asbestos). In those days the soil supply business was not run by experts in soil, but instead by the haulage industry. Topsoil was simply another commodity that was moved

from site to site, with occasional temporary storage in a haulage yard.

There was a welcome initiative by the government of the time to encourage the redevelopment of brownfield sites and discourage greenfield development. Consequently, the readily available supply of natural soils dried up. Around the same time, other schemes meant that it became logistically and commercially viable to manufacture soils for the landscape and construction industry. These included the EU directive for recycling household garden

waste, the introduction of a tax on primary aggregates, and changes in contaminated land remediation requirements that ruled out the use of skip waste soils.

Of course, the concept of blending materials together to make a growing medium was nothing new. The horticultural sector had been making potting mixes for many years. For example, in the 1930s John Innes, the renowned British horticulturist, developed a series of standardised potting composts. These were made with varying recipes of peat, sand,

2.

2. A freshly manufactured soil.

sterilised loam, fertilisers and lime, and their introduction revolutionised plant propagation and container gardening.

Sports turf also had a longestablished history of using man-made soils in the form of sand rootzones for golf courses, bowling greens, and sports pitches. There was a heavy reliance on highly processed washed sands, peat, and fertilisers for many of these.

The land reclamation sector had also developed methods for remediating old mining sites into country parks, forestry, and agriculture. Here, existing spoil materials were improved with various additives including sewage sludge, paper pulp, and waste lime.

All these previous activities presented useful precedents for making landscape soils. The principal difference between them and manufactured soils was their application, and the types of materials that were commercially available and technically appropriate.

Certainly, the use of peat has never been entertained as a component of manufactured soils, and sewage sludge has its difficulties with regard to heavy metals, odour, and handling ability.

There were a few false starts, where poor-quality manufactured soils were dumped onto the market, and landscape schemes drastically failed. This led to a bad reputation that was difficult to eradicate. As far as I am aware, the first landscape project where manufactured soil was completely relied on and highly successful was Bluewater Park in Dartford, Kent. A total of 60,000m3 of topsoil was manufactured for this project, a retail park positioned in the base of a former chalk quarry. George Longmuir of Freeland Horticulture is credited with producing this topsoil, and Freeland Horticulture went on to become the first fully dedicated topsoil manufacturer in the UK. Once the demand became apparent, others started to emerge.

The soil manufacturing industry has evolved to now service the entire UK, with some companies strategically setting up regional hubs. In the past, the soil supply industry was effectively run by waste and haulage companies, with little knowledge or appreciation of their products. However, the bar has now been significantly raised. Many soil companies work to recognised quality-assurance standards, employ technically competent staff, invest in product development and enhancement, and run independent, quality controlled, compliance testing programmes. Most of the materials used to make these soils are derived from recycled or repurposed resources.

Designer soils

It is widely recognised that soils fulfil several essential functions and support ecosystem services and naturebased solutions that are central to social, economic, and environmental sustainability. This is particularly the case in urban environments, for example:

– Provision of habitat for flora and fauna

– Promotion of biological diversity

– Water management through infiltration, retention, filtration, and groundwater recharge

– Carbon capture and storage

– Temperature control through thermal insulation from green roofs

– Support for infrastructure development

– Contaminated land remediation

By selecting soil materials with the required properties and at the correct mixing ratios, it is possible to manufacture soils that deliver most, if not all, of these requirements. Manufactured soils come into their own on projects that do not have an existing soil resource to reuse, for example, a podium landscape scheme built over a slab, or where the existing ground is contaminated. In these instances, the required soils can be specified, sourced, tested, and imported to suit the project’s construction programme. If a site has existing soils, but they do not possess the exact properties required by the

3. A self-sustaining manufactured topsoil 10 years after placement.

3.

1 BS 3882:2015

Specification for topsoil and requirements for use, BSi, 2015

2 The SuDS Manual, CIRIA, 2015

3 BS 8601:2013

Specification for subsoil and requirements for use, BSi, 2013

4 Trees in Hard

Landscapes – A Guide for Delivery, Trees & Design Action Group, 2014

landscape scheme, it may be possible to manufacture more suitable soils through on-site amelioration.

Soil properties (e.g. pH value, drainage rate, fertility status, weight) can be tailored to suit the needs of the project, with more than one soil used where the requirements are diverse. With the arrival of Biodiversity Net Gain (BNG), it is even more important that the soils have the necessary characteristics to support the target habitats. For instance, recycled sands and demolition arisings are now

Soil Type

General purpose topsoil

Low fertility soil*

Calcareous soil

more viable materials to create the necessary environmental stresses for open-mosaic habitats.

Most manufactured soils are easier to handle and spread without impacting their drainage and aeration characteristics, which is a great benefit on construction sites. If the materials used to formulate the soil have no seed bank, the new landscape should have a clean slate to establish into. This is another advantage, particularly for BNG implementation.

The following table lists examples of soils that are routinely manufactured today. Of course, some can also be sourced from reserves of naturally occurring soils.

The soils used for sustainable drainage systems (SuDS) may derive from several of these soil types. It is not always the case that the soil needs to be fast draining as some SuDS designs can accommodate slowerdraining soils that will be more suited to the planting palette and climatic conditions.

Key Features Applications Related Standards / Guidance

– Broad pH range

– Moderate to high sand content

– Moderate to high organic matter and nutrient content

– Low to moderate stone content

– Low nutrient content, especially phosphorus – Low seed bank preferable

– High pH – High lime content

Ericaceous soil – Low pH – Non-calcareous

Marginal topsoil

– High clay content – Cohesive – Low nitrate and phosphate – Low seed bank preferable

– Trees – Shrubs – Herbaceous – Climbers – Amenity grass – Allotment crops

– BS3882:2015 Multipurpose Grade1 – CIRIA SuDS Manual2

Biodiverse, species-rich habitats –

BS3882:2015 SpecificPurpose Grade – CIRIA SuDS Manual

Calcicole planting

Calcifuge planting

Marginal, wetland habitats

BS3882:2015 SpecificPurpose Grade

BS3882:2015 SpecificPurpose Grade

Free-draining topsoil High permeability Bioretention swales CIRIA SuDS Manual

General purpose subsoil

– Broad pH range – Moderate to high sand content

– Low organic matter content – Low to moderate stone content

Compaction-resistant soils – High sand content – Narrow particle size distribution

Lightweight soils

(sub-categories include high fertility, low fertility, calcareous, ericaceous, freedraining, subsoil)

Load-bearing soils (e.g. Amsterdam tree soil, Stockholm soil, CU structural soil)

– Trees – Shrubs – Herbaceous – Climbers – Amenity grass – Allotment crops

– High-performance lawns – Instant landscapes – Podium landscapes – Temporary car parks

Low bulk density – Green roofs – Podium landscapes – Moveable planters

– BS8601:2013 Multipurpose Grade3

Compaction resistant Trees in hardscape TDAG publication Trees in Hard Landscapes: A Guide for Delivery 4

*Can be combined with other soil types, such as calcareous soil or ericaceous soil

Soil design process

Integrating soil design within any soft landscape design is essential, given the soils’ influence on the success or failure of the scheme. This should cover the protection, recovery, manufacture and re-use of site soils and, if necessary, the sourcing and testing of any imported soils, whether natural or manufactured.

From RIBA Stage 2: Baseline Soil Assessment

The decision to reuse site soils should start early, and ideally by RIBA Stage 2 when other surveys are conducted. If the site has existing soils, some form of baseline assessment is carried out by a soil scientist. This is covered by a Soil Resource Survey in the Defra guidance document Code of Practice for the Sustainable Use of Soils on Construction Sites5 and is relevant for both greenfield

and brownfield sites. It is intended to specifically consider the site’s soils with respect to their landscape, ecology, and reuse potential rather than checking for contaminants or geotechnical properties. The resulting report should confirm the types of soil present and explain their strengths and weaknesses with respect to recovery and reuse. This information will be useful to the client design team, including the landscape architect, ecologist, engineer, arboriculturist, and cost consultant.

From

RIBA Stage 3

Soil Strategy

Armed with the baseline soils information, the soil scientist can develop a Soil Strategy during RIBA Stage 3. This determines what specific types of soil will be required for the project, and how these can be derived (on-site and/or imported).

Other topics covered usually include considerations for soil amelioration, soil management, soil depths, land drainage, tree pit design, and aftercare.

From RIBA Stage 4

Soil Specification

A Soil Specification is prepared to set out the specific qualities that the soils should possess, and how the soil supplier and landscape contractor should achieve them.

Tim O’Hare is the Founder and Principal Consultant of Tim O’Hare Associates LLP. Tim has designed soil systems for many of the UK’s largest urban regeneration projects and is the founder of the annual soils conference, SoilsCon (26 September 2025).

D-MAN Tree Anchor System –

Photo Credit: Rachel Warne

Battersea Power Station

5 Construction Code of Practice for the Sustainable Use of Soils on Construction Sites, Defra, 2009

4. Battersea Power Station: all the soils were manufactured © Willerby Landscapes

1. The resulting image from the project, Co-creative Design Research on Soil Biodiversity & Editorial projects for Blauwe Kamer magazine and the Municipality of Amsterdam.

Living soil

A co-creative research project aims to develop a visual language for professionals and the public to foster a positive approach to soil biodiversity

Jana Crepon

Nafsika Efklidou

Radka Komrsová and Marcia Nolte

Since January 2023, Inside Outside has been working on the design research project Living Soil, supported by the Creative Industries Fund NL as part of the Building from the Soil programme. This research explores the hidden biodiversity beneath our feet – an ecosystem more biologically diverse than what exists above ground. A vital soil plays a crucial role in mitigating climate change, storing carbon, purifying water, and preventing erosion. Yet urban development continues to degrade this essential habitat.

Our co-creative design research brought together soil scientists (Naturalis, WUR, and VU Amsterdam), ecologists, designers, artists, municipalities, landscape professionals

and technical advisors. Through Open Studios, lectures, and in-depth research, we worked towards a visual language that makes soil life visible, highlighting its complexity and beauty while inspiring designers, clients, and the public to support its restoration.

The first phase focused on making the invisible visible, culminating in a 1:1 scale drawing of a vital soil ecosystem in loamy sand. This artistic representation captures the interactions between organisms, from earthworms shaping soil structure to mycorrhizal fungi and plant roots forming underground networks. The drawing does not aim for scientific perfection but rather to ignite curiosity and empathy for an endangered yet vital ecosystem.

In the second phase, we expanded our scope to urban soils, analysing their potential as biodiversity reservoirs. Exploring diverse conditions – from compacted urban ground to

artificial soils on rooftops – revealed unexpected richness in spaces between hardscapes and green areas. A 3m-long cross-section visualised how soil life responds to urban pressure and design interventions. Our research underscores the need for long-term soil stewardship – embracing spatial diversity, succession processes, and connectivity in urban design. The resulting visualisations, exhibited across multiple venues, continue to raise awareness and advocate for a paradigm shift in how we treat soil in cities.

Jana Crepon, is a Landscape Architect at Inside Outside and leads the Living Soil project.

Nafsika Efklidou, is a multidisciplinary design researcher at Inside Outside, focused on nature-inclusive design.

Radka Komrsová and Marcia Nolte, are landscape architects at Inside Outside and specialise in sustainable landscape designs and urban development strategies.

Soil and ecosystem services: What does the research say?

The role of soils in ecosystem services clearly demonstrates their value as a multifunctional asset that supports all aspects of life. However, their sustainable management in urban environments is a knowledge gap that must be closed through greater collaboration.

Laurence Jones, David A. Robinson, Alejandro Dussaillant

Soils support the functions that maintain life. Its components can be described as natural capital that supports the capacity to deliver ecosystem services; these in turn provide the benefits we receive as a society.1 However, the way we manage and change soils means they are subject to threats that result in the degradation of capital, and hence a reduced capacity to deliver ecosystem services. Landscape and planning professionals can work with soil natural capital and ecosystem services to enhance environmental sustainability, climate resilience, and human wellbeing. In this article we offer a short overview of the benefits provided by urban soils, along with some key knowledge gaps.

Ecosystem services frameworks typically identify four main types of service. Underpinning everything are the supporting services, which include a suite of soil processes and

functions that drive nutrient cycling, the decomposition and breakdown of organic matter, and water storage or transport. Soil provides a living space for soil organisms, from microbes and invertebrates to larger animals and even birds, and this biodiversity governs many soil processes. These functions in turn support the three classes of ecosystem services that generally receive more attention. These are provisioning services (food or biomass crops, soil as a material or product); regulating services (where soil mediates flows of gases, water, energy, and contaminants); and cultural services (the non-material benefits that people receive from ecosystems, including spiritual enrichment, aesthetic experiences, and recreational activities).

Particularly in urban settings, the function of soils has a huge influence on our quality of life. Any area with growing vegetation, such as grass verges, gardens or parks, will be slowly locking up carbon in the soil. When new areas are sealed by roads, hard surfaces or buildings, even though the disturbance during construction will considerably disrupt and release some of that carbon, the residual carbon remains buried underneath, and can be greater than the carbon in ploughed agricultural fields.2

One urban challenge of increasing importance due to climate change is

surface flooding. During high-intensity rainfall events, the rate at which water can infiltrate into soils in green spaces helps prevent flooding, and higher organic matter content in soil stores more water. As well as this, soils can play a key role in water filtration and purification as they are a natural filter of pollutants, aiding in the breakdown of chemicals (as in the Heathrow wetlands3). How we design and manage our green spaces makes a big difference.

Soil plays a key role in some lesser-known regulating services: for instance, the moisture stored in

1 Natural capital and ecosystem services, developing an appropriate soils framework as a basis for valuation. Soil Biology and Biochemistry, Robinson, D.A., et al., 2013, pp.1023–1033.

2 Organic carbon hidden in urban ecosystems, Edmondson, J.L. et al., 2012, Scientific Reports

3 newcivilengineer. com/archive/heathrowconstructed-wetlandsproject-15-03-2001/ 4 nrcs.usda.gov/ conservation-basics/ natural-resourceconcerns/soil

“I saw all the people hustling early in the morning to go into the factories and the stores and the office buildings, to do their job, to get their check. But ultimately it’s not office buildings or jobs that give us our checks. It’s the soil. The soil is what gives us the real income that supports us all.”4

Ed Begley, Jr.

1. The way soils are treated in urban environments has profound impacts on the ecosystem services they provide. Integrating sustainable drainage systems (SuDS) helps to build urban soil health, contributing to flood and urban heating resilience.

Read more in the Winter 2023–24 ‘Water’ edition of Landscape © AtkinsRéalis.

soil, together with evapotranspiration by trees, helps to cool urban environments. Conversely, when soil moisture is limited, it can intensify heatwaves. Research5 estimates that interactions between low soil moisture and high air temperature can increase the duration of heatwaves by 50–80%. Soils also help reduce noise levels. Soft ground is excellent at absorbing low sound frequencies, and this is factored into the noise models that calculate how far road and rail noise propagate away from the source.

Soils’ support of cultural services is largely unstudied yet ironically is among the oldest evidence we have of creativity, through the use of ochre and other soil-based pigments by both

modern humans and Neanderthals. Soil fauna, such as earthworms and ants, inspire interest in children from an early age. Soil textures and colours shape our cultural context and meaningful relationships with landscapes, for instance the red sandstone soils of the Midlands, or the dark peaty fenland soils in parts of East Anglia.

Although soil science has been studied for at least 150 years, and arguably much longer depending on your definition, many gaps in our knowledge remain. This is particularly the case in cities, where management of soils in green spaces is very different compared to where soils are typically studied in agricultural settings, forestry, or semi-natural habitats.

Does our management of parks for recreation influence their ability to store carbon or the infiltration of flood water? How long does an artificial soil take to become more like a naturally formed soil; will it support the same biodiversity; and how does its function change over time? Can we ‘design’ more multifunctional artificial soils with properties that serve multiple purposes from the outset? Do novel substrates in green walls and green roofs function meaningfully as a soil? These questions are best answered by partnerships between scientists and the citizens, companies, institutions, and authorities that are responsible for much of the land management in cities. Working in partnership can help us to understand the impact of our actions on soil function, and how we might improve the outcomes for all our benefit.

Laurence Jones is Group Leader and Principal Research Scientist with oversight of urban research, David Robinson is a soil specialist and Principal Research Scientist, and Alejandro Dussaillant is an Engineer and Senior Hydrologist at the UK Centre for Ecology & Hydrology.

Soil ecosystem services

Jellicoe Lecture

The Landscape Institute’s recent Jellicoe Lecture was on ‘Making places fit for living’ and focused on the importance of landscape and nature-based solutions in delivering high-quality, sustainable housing. Here, three of our guest speakers share their thoughts on the event.

The Institute’s Jellicoe Lecture on ‘Making places fit for living’ attracted a capacity audience, reflecting the potential for landscape professionals to engage with the government’s ambitious agenda for housing growth. The role of the planning system in promoting and delivering good landscape design and management was emphasised by the speakers in their presentations and in the ensuing panel question session.

Given the government’s prioritisation of growth and its proposals to reform the planning system to enable this, it is vital that landscape treatment is presented as a key part of the solution, rather than being perceived as adding optional and costly constraints. The government is well aware of the tensions between its emphasis on growth and its commitments on environment and climate and is seeking ways of resolving these.

There is therefore an opportunity window for landscape professionals to market their skills in delivering sustainable, nature-based and cost-effective contributions to new housing and infrastructure projects. To support this, national and local planning policies need to embrace a landscape-led approach, as exemplified in the South Downs

National Park Local Plan. And the Institute and all its members need to get the message to diverse audiences that well-planned, designed and managed landscape brings real and valuable paybacks for people, place and nature.

Ian Phillips CMLI is Chair of the LI Policy & Public Affairs Committee

1. The audience at the Jellicoe Lecture gathered professionals from across the built environment industry.

© Nick Harrison FLI

2. Audience engagement stimulates debate and progresses the conversation.

© Nick Harrison FLI

In response to the government’s emphasis on housing growth and review of the planning system, we were asked to reflect and give a personal view on how landscape and nature-based solutions could ensure delivery of high-quality, sustainable living places. The three speakers looked at how the legislative and guidance tools help to deliver this across varying scales, from regional planning to masterplanning. I discussed how as a profession we approach the detail of landscape-led design to create truly sustainable new housing developments.

I looked at a brief history and the place of landscape within housing over the past 200 years, from speculative Georgian streets and squares up to the massive housing boom in 1960s and 70s when millions of new homes were built. By the later decades of the 20th century, play and trees were often delivered on larger housing estates. But little

thought was given to how open spaces and public realm was used by residents and how it contributed environmental benefits.

I then presented two of my practice, BBUK Studio’s projects, including Abode in Cambridge and Old Malling Farm in Sussex, which has recently achieved planning permission.

We concluded that landscape-led developments must have homes with landscape and the site’s context embedded; open spaces (particularly play, often overlooked) to encourage passive surveillance; priority for pedestrians and cyclists, not cars on the streets. This approach gives opportunities for social capital and social cohesion for all generations, and for local wildlife and ecology to thrive.

Harriet Bourne FLI is a Director at BBUK Studio

3. Harriet Bourne FLI delivering her talk.

© Nick Harrison FLI

4. LI President Carolin Göhler.

© Nick Harrison FLI

Jellicoe recognised the role of artists in seeing the world afresh, leading me to begin my talk with a favourite painting of mine, Georges Seurat’s Bathers at Asnieres. Seurat depicts working people on the banks of the Seine. Behind them is smoke from industry, places where these men may work in difficult, even dangerous, conditions. But on this hot, breathless day, they are at leisure and absorbed in their thoughts.

It seems to me that Seurat is saying something important about the conditions for wellbeing in a period of immense change.

Today, we have a new government pushing for 1.5 million homes to be built. In this drive, it’s vital that quality is as important as quantity. Not only because of climate and biodiversity, but also

because of growing inequalities. As masterplanners and landscape architects, inclusive wellbeing should be our all-consuming focus.

When places are designed for wellbeing, they have the characteristics that we feel in Seurat’s Bathers. They are close to nature, with a sense of community.

To achieve this, we need new national policy. Wales has a Wellbeing of Future Generations Act, which guides development. England needs its own overarching law, requiring we always act in the best interests of people.

This shift in focus can drive the change we need to see, and all of us, including the Landscape Institute, should be campaigning on this.

Frazer Ozment CMLI is Chair of LDA Design

5. Arup’s London office provided a fantastic venue for the sold-out

Jellicoe Lecture.

© Nick Harrison FLI

6. The Jellicoe panel, chaired by Noel Farrer FLI PPLI.

© Nick Harrison FLI

Celebrating our Fellows

Looking back on an energising and productive College of Fellows event with College Chair, Adam White FLI PPLI

In November 2024 I had the privilege of chairing the Landscape Institute College of Fellows gathering in London. Blessed with sunshine and blue skies, the event welcomed more than 30 Fellows in person, with additional participants joining remotely from America, Greece, France, Scotland, Ireland, and Wales.

The day began with a guided tour of Beech Gardens at The Barbican Centre, led by Professor Nigel Dunnett FLI, Professor of Planting Design and Urban Horticulture at The University of Sheffield. In 2018, Nigel’s groundbreaking Beech Gardens project won both the Fellows’ Award and the Science of Horticulture and Planting Design Award at the Landscape Institute Awards.

Nigel explained how the planting scheme, featuring drought-tolerant perennials and grasses, thrives with minimal maintenance, reducing water use by up to 70% while promoting biodiversity. The design also incorporates a thin soil layer, which further enhances water efficiency and supports the sustainable growth of the plants. The tour was both inspiring and educational, offering a rare opportunity to experience this pioneering project through the eyes of its creator.

A collaborative and engaging Fellows meeting followed the tour, with President, Carolin Göhler FLI, and me leading a round of applause for Nigel and welcoming all the new Fellows in attendance.

The College is a forum of discussion rather than a formal group, with these discussions informing the Landscape Institute’s operational and strategic direction. For anyone else interested in getting more involved with the LI, 2025 is a fantastic opportunity, with elections to Board and Council. Please put yourself forward!

We then welcomed speakers from both Fellows and LI staff, who provided updates on the future of the LI including the new Corporate Strategy, the LI Awards, education, and corporate identity. Lively and engaging discussion followed each of the talks.

With the Landscape Institute approaching its centenary in 2029, marking 100 years since its founding at RHS Chelsea in 1929, the meeting concluded with a look forward to LI100. It will be great to have the Fellows, and wider membership, contributing their ideas for how we

celebrate this landmark anniversary. Look out for updates!

The day was both productive and inspiring, leaving us all energised for the future and looking forward to the next Fellows gathering.

Becoming a Fellow of the Landscape Institute gives recognition to your contribution to the profession. It provides opportunities to influence, mentor emerging talent, engage in meaningful collaborations, and help shape the future of landscape.

Visit landscapeinstitute.org/ member-content/fellow/ to find out more.

Adam White FLI is Past President of the Landscape Institute, current Chair of the LI College of Fellows, and Founding Director at Davies White Landscape Architects

1. College of Fellows Chair, Adam White FLI PPLI.

© Nick Harrison FLI

2. Landscape Institute Fellows gather at Beech Gardens at the Barbican, for a special tour from Nigel Dunnett FLI.

Adam White FLI PPLI

Elections 2025: Inspire, promote, represent

Calling all change makers! Play a part in shaping the future of the LI at this year’s elections – nominations now open!

This year the Landscape Institute is holding its biennial elections of the Council and Board of Trustees – including the leading role of President.

There has never been a more important time to get involved and make a difference at the LI and within the wider profession, to benefit people, place and nature. The elections are an opportunity to have a tangible impact on our future and inspire the next generation.

Elections 2025 timeline

End of March: Applications open

End of April: Applications close

May: Elections open

June: Elections close

1 July: Start date for all elected candidates

Standing for President

The President, along with the President-Elect and VicePresident, plays a pivotal role as the leading figurehead and ambassador for the Landscape Institute and our members. They provide leadership across the sector and wider afield, advocating on our behalf and seeking to influence key decision-makers.

Key responsibilities include:

– Representing the LI across the membership and the wider landscape profession as well as externally across the UK and internationally, advocating around the key issues, priorities and challenges relating to landscape planning, design and management.

– Chairing the Council as the members’ representative body and ensuring Council fulfils its duties and responsibilities and ensures the Board of Trustees and staff are kept abreast of members’ views and needs

Anyone looking to be the LI’s next President should be passionate about landscape and the essential role landscape professionals play an in shaping the environment in which we live, work and socialise. They should be committed to delivering the LI’s Corporate Strategy and the achievement of the LI’s strategic outcomes.

Standing for Council

The Council supports and guides the direction and focus of the work of the LI. It is the lead representative for the voice and views of members and advises the Board and staff team on key issues, priorities and challenges of the members relating to the practice and professional development of landscape planning, design and management.

The Council oversees the work of the Standing Committees, focused on the priority areas for the LI, and members, and is one of the key routes for Branches to have a voice within the LI.

Members of Council advise on key issues, priorities and challenges of the members and share their professional expertise, experience and networks to input into future plans and feedback to members on the Council and LI activities.

Preparing to apply

If you are interested in applying, or would like more information on the requirements and expectations of standing for election, visit landscapeinstitute.org/ elections or contact regulations@ landscapeinstitute.org.

Figure 1: How each of the elected roles sits across Board and Council.

Figure 2: The LI’s wider organisational structure, showing how Board, Council, and the LI’s new Board and Standing Committees work together to drive influence and growth.

Essential, expert, inclusive

CEO Rob Hughes looks ahead to our 2025–26 Business Plan and a bustling programme of work, driven by our members.

Rob Hughes

Landscape-led approaches are essential to deliver sustainable solutions to societal needs.

Landscape professionals have the expert skills and knowledge to plan, design and manage landscapes that enhance life.

– The Landscape Institute is an inclusive, trusted community that sustains positive change.

Our new Business Plan for 2025–26 has been prepared with these strategic outcomes in mind.

With the government’s development agenda across housing and infrastructure, and the impacts of the climate and nature crises increasingly being felt, the LI will continue to highlight the vital role of landscape professionals, working for people, place and nature.

We’ll be developing the LI’s education strategy, increasing our policy visibility and influence, strengthening our voice externally,

uplifting our membership offer, and continuing to deliver our change programme.

We’ll also be refreshing our brand identity to help boost our impact, and begin launching our new digital home, which will improve the experience and efficiency of working with the LI for all.

This is all part of an ongoing process of rejuvenation. Last year we put in place solid foundations at the LI: stabilising finances, despite a challenging economic environment; recruiting and retaining staff to better equip the LI; and initiating our digital infrastructure programme, all of which have paved the way for increased future influence, improved membership benefits and growth.

Our members are at the heart of everything we do, and we’re delighted to now have in place our four new Standing Committees; Policy & Public Affairs, Knowledge & Practice, Membership & Professional Standards, and Education & Careers.

These committees help to oversee, steer and deliver much of our member

and external-facing work. We’re grateful to everyone who applied to contribute and look forward to working with the new teams in place.

This spring and summer we are also conducting our biennial elections, in which a range of positions across our Board and Council, including President, will be elected for 2025–27. It has been fantastic to witness the enthusiasm and engagement that this has generated across the membership so far – please keep up your amazing work nominating and voting!

With existing and new leaders from across the profession helping to maintain our programme continuity and drive us forward, we look ahead to the launch of our new Corporate Strategy this summer with much excitement.

Visit landscapeinstitute.org for more information on our 2025–26 Business Plan

1. LI CEO, Rob Hughes, speaking recently at the LI Jellicoe Lecture

© Nick Harrison FLI

Bringing resilience to the landscape profession

Aydin Zorlutuna FLI

I have been with Arcadis since 2008, a global multidisciplinary company with Dutch origins dating back to 1888. During most of my time at Arcadis I have also been an Assessor for the Landscape Institute’s (LI) Pathway to Chartership (P2C). I have been fortunate throughout my career to gain experience in multidisciplinary projects across the whole range of the P2C syllabus. A proud recent highlight is a landscape-led detailed planning application on a complex site in Bath, for 16 houses for adults with autism and special needs.

Landscape Institute joint Chief Assessor Aydin Zorlutuna explains that people skills are as important as technical skills on the increasingly numerous pathways to Chartership, and calls on existing members to get involved and help support those at the start of their LI journey.

As UK Director for the Arcadis Landscape, Masterplanning and Urbanism team, containing around 100 staff, I know that people skills are as important as technical skills. I have found during my years of assessing that both are essential to support the P2C attainment process. P2C candidates are diverse and unique, many are nervous, some are neurodivergent, and all require assessors to balance their personal attributes and circumstances with the qualities, attitude and professionalism expected of a Chartered Member of the Landscape Institute (CMLI). Part of the assessor’s role is to give candidates the confidence in the assessment interview to do their best.

In more recent years, and in tandem with the introduction of the Landscape Competency Framework (CF), I was invited to support the pilot scheme for the then new Technician Member of the LI (TMLI), aimed at widening the membership opportunities to complementary disciplines, such as GIS consultants, exclusively through the Experienced route (E2T). With the success of the pilot scheme, TMLI has been further expanded to support an Apprenticeships route (A2T). With the introduction of the CF, the experienced route to Chartership (E2C) and to

Fellowship (E2F) were also opened, resulting in what is now a wide variety of membership assessments that the LI community supports. As such, I was invited in 2023 to join Nick Harrison as an additional Chief Assessor, initially for E2T and A2T, but latterly for all but E2F assessments. Since the volume of assessment requirements have grown, we also welcomed John Flannery to the Chief Assessor team in 2024.

In broadening its membership opportunities the LI is evolving. Supporting this evolution by volunteering some of your time as an assessor, monitor, mentor or supervisor, and by bringing your knowledge to help the next generation of members, is a truly rewarding experience. In doing so you will be building greater resilience in the professional membership community, and helping to shape the future of the LI. I would highly recommend it.

Aydin is a Fellow and joint Chief Assessor of the Landscape Institute, with over 33 years of experience in the private and voluntary sectors. He also holds a Permaculture (Full Design) qualification and is the UK Director of Landscape, Masterplanning and Urbanism at Arcadis.

1.

1. Landscapeled proposed accommodation for adults with autism and special needs at Englishcombe Lane, Arcadis with Bath & North East Somerset Council.

© Arcadis

LI Campus

LI Campus offers access to all LI recorded events including three years of online events and conferences. campus.landscapeinstitute.org

Vectorworks

How landscape design contributes to effective soil conservation

Available to download on LI Campus

How digital tools can streamline the design process and aid decisionmaking to enhance soil health.

Landscape design plays a pivotal role in soil conservation while focusing on the proposed landscape’s aesthetical and ecological value. The primary objective of landscape design in this context is to enhance soil health, prevent soil erosion, and promote biodiversity. With an effective planning strategy, balanced land use, and diverse plant selection, landscape designers can create resilient ecosystems that protect and nourish soil. With the assistance of digital tools, the design process can be streamlined, while helping designers to assess the existing site conditions or to produce cut and fill calculations more effectively.

One key design objective is to implement vegetation that stabilises soil. Deep-rooted plants, such as native grasses and shrubs, are often incorporated into designs to create a dense root system that minimises erosion, enhances the

soil structure, and contributes to carbon sequestration. Additionally, incorporating contour planting and terracing can effectively manage water runoff, reducing the risk of soil degradation.

Digital tools have revolutionised landscape design, allowing for more precise planning and execution. Geographic Information System (GIS) and computer-aided design (CAD) software enable designers to map the soil types, analyse topography and hydrology and calculate the volume of soil enhancements to form a healthy soil matrix for the proposed planting, all of which lead to informed decisions that enhance soil conservation. These tools facilitate the creation of detailed site plans that integrate sustainable solutions, such as rain gardens or permeable paving, helping to manage stormwater and reduce surface runoff.

The positive environmental impact of effective landscape design extends beyond soil conservation. By fostering healthy ecosystems, designers contribute to carbon sequestration and enriched biodiversity. The use of local resources and materials is crucial for reducing embodied carbon. Having a digital representation of the existing products and materials not only helps with carbon estimation and producing accurate material take-offs, but also leads to resourcefulness as it helps

to minimise soil waste and material consumption.

Ultimately integrating landscape design and soil conservation practices contributes to a sustainable environment that benefits both people and planet. By embracing innovative design strategies and digital tools, landscape architects can lead the way in preserving soil while creating resilient landscapes.

1. Digital tools have revolutionised landscape design, allowing for more precise planning and execution.

Vectorworks,

1. Blakedown is an award-winning landscaping and civil engineering expert, delivering outstanding projects across the UK.

Blakedown Landscapes Contracts for collaboration

Available to download on LI Campus

© Blakedown 1.

Blakedown Landscapes provide a contractor’s perspective on understanding Contractor’s Design Portion (CDP) in construction projects

CDP is an important concept within construction, especially in projects using JCT contracts. Essentially, it offers a hybrid approach that blends traditional design responsibilities with elements of Design and Build (D&B). CDP allows contractors to take responsibility for specific design elements while the overall design remains under the design team’s control. This collaborative method is particularly valuable for specialised components where contractors’ expertise can enhance feasibility and efficiency.

Why CDP is effective

CDP allows contractors more control over design implementation. They can adapt designs to align with real-world construction methods, reducing the risk of delays and costly rework. Collaboration between contractors and design teams is enhanced, leading to better problem-solving and cost management. Contractors can propose

cost-effective materials or techniques based on their hands-on knowledge, keeping projects within budget while maintaining quality.

Moreover, CDP promotes innovation. Contractors responsible for certain design aspects can suggest creative solutions or methods that may not have been considered initially, improving functionality and project performance.

Challenges of CDP

Despite its advantages, CDP comes with challenges. Tender accuracy can be tricky. Estimating the cost of specialised design elements during the tender process can be difficult, particularly when the design involves components outside the contractor’s usual expertise. There’s a risk of underestimating or overestimating, which can lead to issues later in the project. Tight project timelines may also suffer from delays due to the additional time needed to finalise CDP designs, secure approvals, and implement changes.

Increased liability is another concern. When contractors take on design responsibilities, they also assume the risk for design flaws. If issues arise, contractors face potential disputes or costly revisions.

Additionally, conflicts may occur with the design team. Sometimes,

contractors might propose changes for practical reasons, but these changes might not align with the original vision of the design team. This can cause friction and affect the overall project.

Best practices for success

For CDP to succeed, early engagement between contractors and design teams is crucial. Contractors should participate in initial design discussions to align expectations and avoid misunderstandings. Clear documentation helps maintain consistency and reduces miscommunication risks. Maintaining open communication throughout the project ensures issues are resolved promptly. Regular meetings between contractors, design teams, and clients facilitate smoother project execution.

Conclusion

CDP offers contractors a chance to leverage their practical expertise, enhancing collaboration, efficiency, and innovation. Though challenges exist, with early engagement, clear communication, and teamwork, CDP can deliver specialised elements smoothly and to the highest standards.

Commercial Stone & Paving for Inspirational Spaces

By carefully repurposing and re-cutting the existing heritage sandstone, Hardscape helped this revitalisation project maintain the character and authenticity of the Quadrangle, sustainably blending the new installation seamlessly with its historic surroundings, with minimal environmental impact.

The Old Quadrangle, Manchester University

Client: The University of Manchester

Landscape Architects: Iteriad Ltd

Architects: Wilson Mason LLP

Contractor(s): RECOM Solutions Ltd,

CS (Civils and Groundworks) Ltd and

MBC Building Contractors

Civil Engineers: WML Consulting