On water

Water quality is important for the proper functioning of freshwater and marine ecosystems and for human use in drinking water, irrigation and industry. Good agricultural practises have been identified to reduce the risk of polluting water while allowing economic agriculture to continue.

Water Quality Issues.

Two quality issues related to crop nutrients have been identified, nitrate and phosphorus, and both are covered comprehensively in Agriculture, Fertilizers and the Environment written by a team of Yara researchers with contributions from recognised scientists from all over the world. We produced this book - first written in 1990 and restricted to European conditions, and updated and published as a second edition from a global perspective in 1999 – with the purpose of providing a balanced scientific review of the environmental and sustainability issues relating to fertilizer use, and how its environmental impact can be minimised.

Excessive nitrate in drinking water was thought to be associated with blue baby syndrome and gastric cancer. Both of these concerns have proven unfounded but limits on the nitrate concentration in water have remained in place in many countries. Field experimentation has shown that the nitrate concentration in water can be minimised if the supply of available nitrogen closely matches crop requirement. This prevents any excessive amount of nitrate in the soil that can be lost to water through leaching. Phosphorus is often the limiting nutrient for algal growth in fresh waters and enters water with soil particles that erode from land. Again, close matching of available soil phosphorus to crop need minimises loss to water. Management of organic manures on farm land continues to be a major challenge to preserving water quality.

The role of mineral fertilizer.

Yara provides a complete range of mineral fertilizers to meet different crop requirements and has invested heavily in advisory systems to ensure accurate matching of nutrient supply and crop need to meet good agricultural practise.

Agriculture, Fertilizers and the Environment. M Laegrid, O C Bockman and O Kaarstad. CABI Publishing, 1999, 294pp, ISBN 0-85199-358-3.