MPs on the Environmental Audit Committee (EAC) of the House of Commons have launched an investigation into the health of Britain?s soils. The aim is to consider how soils management and measurement of our can be improved. The committee will look at existing soil protection regulations, and then determine whether further action is needed.
Soil health is crucially important for food production, and is increasingly being linked with general population health. It also plays a vital role in sequestering carbon. DEFRA?s soil management strategy, which appeared in 2009, stated that UK soils contain 10 billion tonnes of carbon. Healthy soils also help to prevent flooding; such a soil will absorb much more water than one that is compacted, or where erosion gullies have formed.
Soils face three main threats: erosion, decline in the amount of organic matter, and compaction.
Soil erosion is a serious problem; around 2.2 million tonnes of topsoil is lost to erosion annually in the UK. The problem is more acute in particular areas, such as the Fens of East Anglia, where the light, peaty soil is blown away in dry, windy weather. On sloping ground water erosion is more significant, and the formation of gullies can lead to considerable loss of soil, in addition to making downstream flooding more likely. The planting of trees as windbreaks, along with the use of cover crops, can reduce wind erosion. Ploughing along contour lines on slopes can help reduce erosion due to water run-off.
Arable soils tend to lose organic matter over time. This can be replenished by adding farmyard manure or other sources of organic matter. However, if purely inorganic fertilizers are used, and no other steps are taken to replenish the soil with organic matter, then arable soil will tend to become deficient. Techniques such as the use of green manures (crops that are ploughed back into the soil) can increase the amount of organic matter present. A soil denuded in organic matter will tend to be of poor quality and lack nutrients, adversely affecting crop yields. In 2007, the Environment Agency estimated the costs of organic material decline in soils to be about ?82m per annum.
Compaction caused by heavy farm machinery can be very detrimental. It means that less water is available for crops and more runs off the land, making flooding more likely. Good practice with regard to the use of machinery can reverse the damage caused by compaction.
In addition to the above threats, contamination of soils is a problem in some areas. Typically this occurs on brownfield sites, but it may also occur on farmland, where possible sources include old mining sites, and the use of contaminated materials as fertilizers or soil improvers.
The environment agency produced its ?Soil management standards for farmers? in 2012. These standards outline the requirement on farmers to produce an annual soil protection review (SPR) in order to qualify for the full amount of payments under the single payment scheme (SPS). The document contains much sensible advice on avoiding soil degradation.
The EU were due to produce a Soil Management Directive, however this process seems to have collapsed entirely, so no new EU regulations are expected. Some organisations, such as the Soil Association (an organic farming NGO), believe that further action is needed to preserve soils. A large number of farmers are fully aware of the need to protect their soil, and have been taking soil conservation measures, such as planting windbreaks and using machinery so as to avoid compaction, for many decades. Others, often managing farms on short-term contracts for absentee landlords, will be much less keen to take action. Neither group is likely to welcome more regulation. The challenge for the MPs is to chart a way forward that does not involve complicated bureaucracy, which will be expensive and resented by farmers, while still halting the degradation of the UK?s soils. The question of contaminated soils also needs addressing, but cutbacks to government expenditure slow the pace of remediation. The MPs may struggle to deal effectively with the contamination issue, since both central and local government are facing severe budgetary constraints.
DEFRA website, ?Safeguarding our soils?, 2009. https://www.gov.uk/government/publications/safeguarding-our-soils-a-strategy-for-england
Environment Agency, ?Soil management standards for farmers?, 2011. https://www.gov.uk/guidance/soil-management-standards-for-farmers
Udall, D., Rayns, F. and Mansfield, T., (The Soil Association & The Centre for Agroecology, Water and Resilience), ?Living soils - a call to action?, 2015. http://www.soilassociation.org/LinkClick.aspx?fileticket=KMGFQY-7sIM%3d&tabid=2416
Source citation: Salvidge, R., ENDS report website, ?MPs launch inquiry into soil health?, 2nd December 2015.