Publication Date
1993
Description
The term "soil quality" is increasingly being used in Europe, albeit in an ill-defined way. Perceived quality depends critically on the use being made of the soil and the tolerance of other parts of the environment to substances moving from soils. This paper focuses on issues relevant to the maintenance of quality in temperate grassland soils. Soils are under threat from heavy metals, organic contaminants and radionuclides because they are sinks for many of these substances, thus lending to accumulation. The impact of these contaminants is assessed, along with the management options and relevant legislation to minimise their effects. Most pollutants do not normally affect the growth of the sward, but may be deleterious to other components of the food chain. Recent evidence suggests that soil micro-organisms are sensitive to increasing soil metal contents, which has implications for long-term soil fertility. Acidification of soil causes changes in productivity and species composition, and it is shown that agricultural practices themselves cause the most rapid acidification. Optimum pH values can, therefore, be maintained in most soils by appropriate agricultural management. Threshold values to avoid the occurrence of deficiency of nutrients in herbage and animals have been used for many years, but the current emphasis is on the avoidance of excesses. Such excesses may lead to negative effects on the quality of air, surface and ground waters. The focus is now on the removal of nutrients in products and their depletion rates in the soil, the aim being to bring about a balance which will prevent large accumulations occurring, but also to ensure that particular productivity requirements are not sacrificed owing to over depletion of the soil reserves. Maintenance of the organic matter content is often a crucial factor in soil quality, because it reduces the sensitivity of soils to chemical and physical degradation. Soil physical conditions are also important, and these can be affected by factors such as agricultural drainage or physical damage. There is a strong biological component of soil quality because of the role of organisms in the cycling of nutrients and maintenance of soil fertility, Soil organisms also affect the soil physical properties in ways that can improve soil structure. It is argued, however, that knowledge of the organisms and their interactions with parameters involved in soil quality is imperfect. A greater understanding of their role is essential to protect the environment by improving future soil management options.
Citation
McGrath, S P. and Jarvis, S C., "Recent Considerations of Grassland "Soil Quality" in Temperate Regions" (2024). IGC Proceedings (1993-2023). 2.
https://uknowledge.uky.edu/igc/1993/session40/2
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Recent Considerations of Grassland "Soil Quality" in Temperate Regions
The term "soil quality" is increasingly being used in Europe, albeit in an ill-defined way. Perceived quality depends critically on the use being made of the soil and the tolerance of other parts of the environment to substances moving from soils. This paper focuses on issues relevant to the maintenance of quality in temperate grassland soils. Soils are under threat from heavy metals, organic contaminants and radionuclides because they are sinks for many of these substances, thus lending to accumulation. The impact of these contaminants is assessed, along with the management options and relevant legislation to minimise their effects. Most pollutants do not normally affect the growth of the sward, but may be deleterious to other components of the food chain. Recent evidence suggests that soil micro-organisms are sensitive to increasing soil metal contents, which has implications for long-term soil fertility. Acidification of soil causes changes in productivity and species composition, and it is shown that agricultural practices themselves cause the most rapid acidification. Optimum pH values can, therefore, be maintained in most soils by appropriate agricultural management. Threshold values to avoid the occurrence of deficiency of nutrients in herbage and animals have been used for many years, but the current emphasis is on the avoidance of excesses. Such excesses may lead to negative effects on the quality of air, surface and ground waters. The focus is now on the removal of nutrients in products and their depletion rates in the soil, the aim being to bring about a balance which will prevent large accumulations occurring, but also to ensure that particular productivity requirements are not sacrificed owing to over depletion of the soil reserves. Maintenance of the organic matter content is often a crucial factor in soil quality, because it reduces the sensitivity of soils to chemical and physical degradation. Soil physical conditions are also important, and these can be affected by factors such as agricultural drainage or physical damage. There is a strong biological component of soil quality because of the role of organisms in the cycling of nutrients and maintenance of soil fertility, Soil organisms also affect the soil physical properties in ways that can improve soil structure. It is argued, however, that knowledge of the organisms and their interactions with parameters involved in soil quality is imperfect. A greater understanding of their role is essential to protect the environment by improving future soil management options.
