Soil conservation measures
- 95% of the world’s food is produced on soil
- One-third of the UK’s soils are degraded
- One million hectares (36% of arable land in the UK is at risk from erosion.
According to the UK environment secretary, Michael Gove, in some parts of the country, the UK’s soils may only be able to support farming for a further 30-40 years.
Conservation agriculture aims to restore soil quality by increasing biodiversity, organic matter and soil fertility. It does not involve any ploughing of the soil but encourages the use of plant residues and/or the planting of cover crops. It also encourages crop rotation and inter-cropping/companion cropping (the harvesting of two or more crops from the same piece of land).
By not ploughing the soil, the loss of organic matter is reduced – research has shown that carbon emissions from non-ploughed soil are 5.8 kg/ha compared with 35.3 kg/ha from ploughed soils. Reduced tillage is more effective on sandy or loam (mixed) soils.
Cover crops protect the soil from wind and water erosion. Crops also store nutrients which otherwise would be washed away by winter rains. These nutrients are released slowly as the crops decompose.
Crop rotation helps restore soil fertility. In addition, companion cropping produces yields which are higher than monoculture (the harvesting of a single crop) by about 50%.
Agroforestry is the harvesting of trees for timber, fuel and/or fruit alongside arable and/or pastoral farming. Trees help protect the soil from wind erosion. They also reduce water loss from soils. They add organic matter to the soil, and their roots protect and bind the soil. Agroforestry also helps climate change by storing carbon. They can reduce the likelihood of flooding and they increase biodiversity, as well as increasing the range of products that a farmer can market.
Pasture-based livestock farming also protects the soil by having a permanent vegetation cover. It helps increase soil fertility through the decomposition of animal manure.
Paludiculture refers to the sustainable use of peatlands for agriculture. Peatlands are very productive ecosystems and store large quantities of carbon. Peatlands are currently used in a number of ways
- pasture and hay-making producing fodder for cattle
- reeds used for building, especially thatching
- sphagnum ‘farming’ for use in horticulture
- Paludiculture reduces carbon loss from perat
There is a need to protect undeveloped land, especially agricultural land and its soil, from new developments. The loss of agricultural land for development is a major concern. When land is developed, many of the ecological services (e.g. flood control, biodiversity, carbon storage) are destroyed. The use of undeveloped land for building has increased from around 52300 ha/year in the early 2000s to around 15,8000 ha/year between 2013 and 2017.
Campaign to protect rural England, 2018, Back to the land: rethinking our approach to soil
Campaign to protect rural England, Save our soils