Abstract
We examined the conditions of ammonia generation during composting and the possibility of collecting ammonia with vacuum-type aeration under the 16 sets of composting conditions decided by the addition of materials to adjust the moisture level of feces and moisture levels of the raw materials. Peak ammonia generation appeared when the compost was at a high temperature in the early stages of composting. Ammonia generation then rapidly decreased for 1 or 2 days after peak ammonia generation. When continual aeration was changed to intermittent aeration at ammonia generation, unidentified nitrogen in the nitrogen balance increased. Thus, we supposed that ammonia was emitted from the compost surface at the cessation of aeration. The rate of the nitrogen shift to the outside of raw materials during the experiments increased in following order; Only Feces or + Rice Hull>+Saw Dust>+Treated Compost. When the rates were estimated as eliminated nitrogen mass from the excreta of 1 milking cow for 1 day, the rates increased in following order; +Treated Compost>+Rice Hull>Only Feces>+Saw Dust. Thus, the addition of treated compost 65% moisture condition caused the greatest nitrogen shift from the compost: 97.0gN/cow·day.
