Mineral nitrogen and phosphate cycles in different agroecosysterns

Abstract

The current investigation compared various intensive crop rotations (Norfolk, row crops, cereals, short-term grass) grown on Cambisols. The results showed significant effects of N fertilization on the agroecosystem and N balance, and on the mineral N concentration in drainage water and its leaching process. The highest N concentration in drainage water and leaching was determined in the cereals and row crops rotations. No major impact of the crop rotation on the P-PO43- concentration in drainage water was determined. The average leaching of P-PO43- by drainage did not exceed 100-140 g ha(-1) within a seven-year study period. A rational and well-considered fertilization regime ensures high crop productivity and profitable farming as well as a steady close-to-neutral N balance, which is the main condition for reducing the on-point source pollution of water