The influence of modified pratotechnics of unmanaged grasslands on the amount of mineral nitrogen in lysimetric waters of the rhizosphere

摘要

In 2001–2004, the influence of various ways of farming unmanaged grasslands on the mineral nitrogen content in lysimetric waters was monitored. Field trials with 11 variants were performed 420 m above sea level, at depths of 0.2 and 0.4 m, 4–5 times annually. The average amount of Nmin released per ha per year in lysimetric waters ranged from 0.84 to 5.12 kg. The upper layer to a depth of 0.2 m had a higher content. The conclusive difference, in comparison with properly farmed control, was with the black fallow and in the variant where fallow followed mulching. With the exception of this method of farming the pratotechnics of unmanaged grasslands – mulching did not increase the load of rhisosphere, either by the overall mineral nitrogen, or by the concentration of N-NO3–. Even by using fallow for a four-year period, a conclusive increase in the content of Nmin was not observed.