10 minute read
Earthlings
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
Soils tell a fascinating story of humankind’s interaction with the earth over the centuries, if we know where to look.
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 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, 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.
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.
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. 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 human induced 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 plough 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 post-Roman 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.
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 small-scale production of quicklime which was mixed, or slaked, with water to make plaster, mortar, concrete, and lime-wash. 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.
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 Mill 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.
Improved transport links in the 19th century also enabled growers to serve distant markets. In Devon, 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. 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. Over the following half century, it is estimated that around 12 million acres of land were drained. 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 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, 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”, 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.
