The post-effect of lucerne on nitrate-N accumulation in a maize-wheat double cropping long-term experiment

Yield and soil nitrate-N was measured in a long-term nutrient supply experi ment in Kompolt, Hungary. The objective of the study was to examine the pos t-effect of lucerne on a winter wheat-maize double cropping system. The res ults suggest that lucerne had significant effect on soil nitrate-N content in 0-300 cm. Nutrient supply modified this effect. The peak of nitrate-N ac cumulation occurred in 150 cm depth. The maximum amount of nitrate-N origin ated from the highest (176 kg N/ha) treatment level without lucerne in the rotation and has not reached 100 kg N/ha, while it reached more than 200 kg N/ha with lucerne. Yield of winter wheat showed significant difference only in case of control after lucerne.