Soils face various risks related to erosion and pollution, however, adopting good land and soil management practices can help mitigate these negative impacts and in some cases can improve the overall productivity of soils. Such practices generally seek to improve soil structure and/or increase cover so as to reduce erosion, increase soil infiltration, and reduce runoff and transport of sediments.
According to Forbes et al. (2015), s variety of techniques may be adopted including:
- cover crops;
- checking for and relieving compaction where required;
- soil aeration;
- machinery practices that minimise compaction; and
- runoff control features (e.g. in-field buffer strips, hedges).
Soil and crop management measures
Covering land with cover-crops during winter can help reduce soil erosion and maintain soil structure and fertility. Applying cover crops also reduces surface run off, the leaching of nutrients, weed control and also provides habitats for other species. Applying cover crops are particularly useful in areas that are drier and have more stable soils. Cultivating land along contours, rather than straight up and down field slopes can be particularly effective in reducing surface runoff.
Another measure is reducing the use or impact of machinery on soil compaction. The implementation of tramline spacing, flexible tyres on machinery, and reduced weight loads can help prevent compaction and ensuing problems of excessive runoff, particularly on wet soils. Another way to improve soil aeration and reduce compaction is to use a soil aerator (mechanical spiking of the soil) in compacted grass field, in combination with other measures, such as tramlines which benefit growth and increase the amount of oxygen reaching roots.
Runoff control features
Watercourses that overflow can cause run-off into fields. Creating vegetated land strips along the banks of watercourses can provide important protection from grazing animals while stabilizing banks and reducing the possibility of erosion. This natural barrier technique can reduce erosion and the amount of water and pollutants reaching the watercourse, while also improving biodiversity. There are several implementation options which vary from simple fencing that allows natural regeneration and protection from stock or it could include some additional elements such as planting of trees and other vegetation.
Sub-dividing arable fields through the planting of grass strips and hedgerows along the contour of a field or within a natural gully can be particularly effective at intercepting surface runoff and increasing infiltration of water into the soil profile. Other agricultural practices and interventions that can contribute to reductions in runoff, such as ditch/ drain blocking and wetland creation, are described in more detail in subsequent sections.