Einfluss der ökologischen Bewirtschaftung auf die Nitratstickstoffgehalte im Boden

Summary

The following paper discribe the influence of ecological managed systems on contents of nitrate-nitrogen in soils. From 1993 to 2003 in a six-year crop rotation in the location of Gülzow (Mecklenburg-Vorpommern) samples of soil were taken with an soil auger in a depth between 0 and 90 cm. Nitrate-nitrogen contents was analyzed by hydrazin reduction in an analysing automat (SKALAR). For statistical evaluation SAS (Statistical Analysis System) and for clearing of unorthogonal data procedure MIXED of PIEPHO and MICHEL (2001) were used.
The results show that contents of nitrate-nitrogen in autumn and spring are lower for organic management than for conventional. Nitrogen losses during winter are subjected to heavy annual variations. High contents of nitrate-nitrogen in the end of vegetation resulted in high losses on sandy soils in winter. The amount of contents of nitrate-nitrogen in the end of vegetation is heavily influenced by the crop rotation and the management connected with this crop. Danger of high losses of nitrate-nitrogen during the winter is especially big in the growing of winter grain with legumes grown before. Losses through leaching can be decreased by catch crops and by high degree of soil covering for example with clover and grass.