Mise en relation de l'évolution de l'agriculture et de la qualité de l'eau entre 1950 et 2000

Abstract

Relationship between evolution in the agriculture and in the water quality from 1950 to 2000. In 1991, Europe has adopted the Nitrates Directive to reduce the impact of agriculture on water nitrate pollution. Nitrate concentration in groundwater has not always been so worrying as it was at the end of the ’80. Working on the revision of Action Programme, it is usefull to list changes in agriculture during the two decades before the degradation of water quality. So, with regards to land use, we observe a huge decrease of grassland cover and an increase of maize surfaces. Livestock has highly increased during this period. Finally, use of nitrogen (mineral and organic) has increased out of proportion to the yield increase. Following this analyze, loss of grassland cover should be at least stopped, nitrogen supplies should strictly correspond to crop needs, taking into account the soil restitutions.

Keywords

• Nitrogen
• nitrate
• water quality
• agricultural practices