Diffuse Agricultural Pollution

Over the last few decades, in our drive for higher crop yields we have made extensive use of fertilizers. However, soil and water resources have been affected by these agro-chemicals so that today, diffuse pollution from agricultural sources is having a damaging effect on parts of the environment and significant cost implications for treatment of our water supplies.

Fertilizers, in various forms of Nitrogen (N) and Phosphorous (P), have been applied intensively over the last few decades to agricultural land in order to improve crop yields. As a consequence increased levels of these nutrients are now found in many lakes, rivers, groundwaters and coastal waters. In some areas levels have risen above safe guidelines for drinking water quality in river water and groundwaters. In other areas nutrient concentrations have risen to levels where they are adversely impacting on ecosystem health and functioning. For example, by promoting the development of algal blooms in lakes, high levels of nutrients can lead to significant reductions in oxygen content of lake water and can cause die-off of fish. Nutrients levels entering coastal waters are also rising in some areas prompting similar concerns about adverse impacts on ecosystem health.

Research on nutrient fate and transport in the terrestrial water cycle over the last couple of decades means that many of the main fate and transport processes of Nitrogen and Phosphorous are well-understood, and current research efforts are focussing on developing a systems understanding of diffuse agricultural pollution at the whole-catchment scale. Important components of the current research effort are targeted at applying that understanding through schemes that demonstrate how changes in land management practices can improve water quality, and through the development of simple policy and planning tools that encompas best evidence and science.

The Demosnstration Test Catchments (DTC) Project is a collaborative activity between policy makers, the water industry and the farming industry to

“find out if new farming practices, which aim to reduce diffuse pollution from agriculture, can also deliver sustainable food production and environmental benefits across whole river catchments”

The EVO is working closely with the DTC Project to add value to this important initiative. In addition, EVO, as part of our National Cloud Services examplar, is developing a nutriant fate model to be run across the web using a range of user-defined scenarios to support policy and planning decision making.

The Natural Environment Research Council-funded Maconutrients Cycles Programme aims to quantify the scales of all nitrogen and phosphorous fluxes through catchmnets under a changing climate and ‘purturbed carbon cycle’, and will provide a wider context for the issue of diffuse agricultural pollution.