The United Nations Environment Programme (UNEP) yesterday announced that the effects of global warming will become more pronounced as agricultural methods accelerate the rate of soil erosion around the world, releasing carbon dioxide into the atmosphere. The UNEP Year Book 2012 states that only dramatic improvements in the way the world manages its precious soils will lead to food, water and climate security.

The UN report, the release of which follows two similar reports on soil management in Europe published by the European Commission, reveals alarming figures about the loss of soil health around the world, showing that unless action is taken to ensure agricultural production does not continue to impact adversely on soil health, much land currently under production may not be available for future generations.

The Year Book shows that, over the past 25 years, 24 per cent of the global land area has already suffered declines in health and productivity as a result of unsustainable land-use. The UN said that this is often the result of conventional and intensive agriculture, which it claims is “Triggering soil erosion rates some 100 times greater than the rates at which nature can form soil in the first place.”

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As good soil, which is itself a complex ecosystem, takes thousands of years to form naturally, scientists view it as a non-renewable resource. Jane Rickson, Professor of Soil Erosion and Conservation at the National Soil Resources Institute, Cranfield University explained, "One gram of healthy soil can contain a billion organisms. Good quality soils are able to deliver many different services. However, we see erosion as an irreversible process." 

Need for change: worrying figures on carbon storage

The findings of the UNEP report suggest that by 2030, without changes in the way land is managed, over 20 per cent of terrestrial habitats such as forests, peatlands and grasslands in developing countries alone could be converted to cropland, aggravating losses of vital ecosystem services and biodiversity. Though currently schemes like REDD are reporting successes from paying developing nations for preserving their forests, the need to produce food and increased land degradation could put pressure on this.

As well as biodiversity loss and the loss of some vital ecosystem services, degradation could have profound implications for climate change. Soils contain huge quantities of carbon in the form of organic matter that in turn binds the nutrients needed for plant growth and allows rainfall to penetrate into underground aquifers. However, since the 19th century, an estimated 60 per cent of the carbon stored in soils and vegetation has been lost as a result of land use changes, such as, clearing land for agriculture and urban development.

When lost, the carbon stored in these soils turns to carbon dioxide, a potent greenhouse gas. UNEP warns that, if existing patterns of land management continue, increasing amounts of this carbon could be released to the atmosphere, aggravating global warming linked to the burning of fossil fuels.

Furthermore, the report shows draining super carbon-rich peatlands is currently producing more than 2 Gt of CO2 emissions annually, contributing to six per cent of anthropogenic greenhouse gas emissions (those that come from humans). The degradation of peatlands is happening at a rate 20 times greater than the rate at which the peat, and thus the carbon stored within, is accumulated. In the UK, an industry and government task force is looking at alternatives to peat, though the industry has proven reticent to act without other peat-using nations jumping first.

European reports show effects closer to home

Two reports released this week by the European Commission have also shown the effects soil erosion and soil sealing are having on the environment and its ability to sustain humans. The reports showed that, between 1990 and 2006 in Europe alone, at least 275 hectares of soil per day were permanently lost through soil sealing (the covering of fertile land by impermeable material) and that soil erosion by water affects 1.3 million km². The result of this is that, over the period studied, 19 Member States lost a potential agricultural production capability equivalent to a total of 6.1 million tonnes of wheat.

Experts have said this is far from trifling, as agricultural productivity is leveling off and, in order to compensate for the loss of one hectare of fertile land in Europe, it would be necessary to bring into use an area up to ten times as large in another part of the world.

As well as impacting on biodiversity and accelerating climate change, the loss of healthy soil will also affect productivity; intensive and continuous arable production are thought to be leading to a decline of soil organic matter and this soil erosion is jeopardising production. In the last major UK soil study, conducted in 2009, it was revealed that Britain loses almost 2 million tonnes of topsoil each year. Since that time, no national study has been conducted to monitor the process, although research institutions claim they are monitoring high risk soils

Reports show promise, though reinforce need for paradigm shift

Late last year, a report by French Green MEP, farmer and celebrated activist José Bové illustrated the pressures farmers face; those of increasing input costs, margins squeezed under pressure from retailers and processors, and the threat of climate change affecting their viability.

M Bové’s report showed that, in the past decade, the price of fertiliser and soil improvers have increased 80 per cent. These tools, although their effect on agricultural output has been unprecedented, have been called “blunt instruments” by soil scientists, who claim healthy soil needs a wide variety of inputs and biological activity to maintain it and produce nutritious foods. With speculation over rising costs and monopolies developing within the global fertiliser market increasing concerns for farmers reliant on the products, there has been growing interest in alternative ways to maintain soil health, including remineralisation and agroecological methods, which embrace a more holistic, rather than market-centric view of the place of farming.

M Bové’s report for the European Parliament was adopted with an overwhelming majority earlier in the year; in it, he made calls for the EU to roll out efficient measures and incentives to promote crop diversification and protein security, including planting of legumes and crop rotation adapted to local conditions, to be included in CAP reform negotiations. He stated that these measures will have a positive effect on climate change mitigation, soil and water quality and the ability of farmers to reduce their input costs.

He also said improved analysis and management of nutrients on farm, cutting back fertiliser expenditure through better soil fertility analysis and management and improving soil crumb structure and organic humus levels (which allows for better water and nutrient retention) through manuring and better crop rotation would go some way towards sparking the “ever-green revolution” which policy makers have said is needed to ensure food production remains viable in the face of a growing population and environmental concerns.

The UNEP report also reveals areas where action will have the most promising results. It shows that reforestation, improvements of grasslands and paludiculture, an alternative to conventional peatland agriculture, will all contribute towards managing soil carbon. The report also states that improvements in croplands, including integrating several crops in a field at the same time will increase soil health, biodiversity and, in many regions, increase food production.

Both the EU and UN have developed soil charters, which aim to protect this most valuable resource. However, in the EU the finer points of the charter are still subject to discussion between the Parliament and the Commission and, as such, it has not yet been implemented, and, despite lamentation from the UN Food and Agriculture Organisation, the UN charter has not been widely adapted, particularly in areas which are at risk of degradation.  

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