Comissão 3.5 -Poluição, remediação do solo e recuperação de áreas degradadas SheeP exCreta aS SourCe of NitrouS oxide iN ryegraSS PaSture iN SoutherN Brazil

. the highest N 2 O-N fluxes occurred 16 days after application of urine and dung, when the highest soil nitrate content was also recorded and the water-filled pore space exceeded 60 %. the mean ef for urine was 0.25 % of applied N, much higher than that for dung (0.06 %). We found that N 2 o-N emissions for the 90-day winter pasture period were 0.54 kg ha -1 for low grazing intensity and 0.62 kg ha -1 for moderate grazing intensity. Comparison of the two forms of excreta show that urine was the main contributor to N 2 o-N emissions (mean of 36 %), whereas dung was responsible for less than 0.1 % of total soil N 2 o-N emissions