Reduction of N surpluses and release of N2O-emission from pasture

The N2O emission from grazed pasture fertilized with different levels of N was studied. Local variability of N2O release was recorded by measuring the emission directly from dung or urine patches, respectively, and from the s ward areas which were unaffected by faeces. Seasonal variability of N2O rel ease was studied by emission measurements extended to 6-11 months. The resu lts obtained clearly show that the amount of N2O emitted per year depends o n fertilization rate. In comparison to intensively fertilized pasture, past ure management without application of mineral N led on average to a reducti on of N2O release per ha by about 70% and per grazing animal by about 50%.