Ammonia and nitrous oxide emissions following land application of high and low nitrogen pig manures to winter wheat at three growth stages

▶ Nitrous oxide emissions were shown to be episodic in nature ranging from 2.8 to 31.5 g N2O-N ha−1 day−1 irrespective of manure type. ▶ Higher nitrous oxide emissions were measured from manures produced by pigs fed a high crude protein diet-emissions reduced by 18% with the use of lower crude protein diets. ▶ Ammonia emissions were highest immediately post manure application with approximately 95% of emissions occurring in the first 24 h post manure application. ▶ Ammonia losses were highest when crop cover was low with total ammonical N losses accounting for 6-11% of total N applied. ▶ No adverse effect on crop N uptake and grain yield production was observed from manures with lower N contents.