Nutrient transfers from soil to water - Influence of agricultural practices - Literature review

Abstract

Nitrogen and phosphorus are found in the soil in various forms. Nitrogen is usually leached in the form of soluble nitrates. Phosphorus is strongly bound to the soil and is carried by erosion and run-off. Farming practices have an effect on the forms of nutrients and the amounts lost and on the way in which they are carried into water courses. Fertilisation, crop rotation, crop residue management, animal effluent management affect the amounts of nitrogen that may be leached; irrigation and drainage techniques play a role in the time taken for the leaching from soil to water. Field improvements, crop rotation and ploughing techniques can damage the soil surface and increase the run-off of phosphorus; regular over fertilisation, especially in stock-breeding farms, increase the loss of phosphorus in the long term.