Abstract: | Altogether 10… 20 kg/ha·a N from precipitation are introduced into the soil. The fertilization of the agriculturally used area increased from 50 to 120 kg/ha·a N between 1950 and 1982. The nitrogen concentration is theoretically increased by 0.4 mg/l due to infiltration of surface water and wastewaters. The data prove agriculture to the main source of the nitrate load of groundwater, especially in regions with predominantly intensive agricultural use there is delivered drinking water with nitrate concentrations of more than 50 mg/l. The fixing of the limit value for drinking water at 50 mg/l nitrate (value recommended by the EC: 25 mg/l) is justified by new findings. Since the technology of nitrate elimination from water is very expensive, mainly the preventing of too high nitrate concentrations should be aimed at by agricultural measures of ground-water protection. |