酸性物质对猪粪秸秆堆肥过程中氮素转化的影响

Effects of Acidic Materials on the N Transformations During the Composting of Pig Manure and Wheat Straw

了解不同酸性物质对堆肥过程中氮素转化和NH_3排放的影响,是筛选保氮添加剂的重要环节,对于堆肥中氮素控制具有重要意义.以新鲜猪粪和小麦秸秆为堆肥原料,磷肥、腐烂苹果和食用醋为添加剂,在实验室进行40 d的静态高温堆肥试验,研究堆肥过程中温度、pH、EC、GI、氮素化合物和TOC含量的变化特征.结果表明,CK、P、A和V这4个处理高温期(>50℃)均持续了10 d以上,达到高温堆肥化卫生标准.添加磷肥延缓了堆体进入高温期的时间,降低了堆体的pH值,使整个过程的EC值保持较高水平.各处理氮素损失分别为53.1%、36.2%、46.5%和41.5%,主要集中在0~16 d之间,而P和V处理在16~24 d之间仍有20%左右的氮素损失.其中NH_3-N损失占氮素损失的26.0%、11.8%、21.5%和20.2%.添加酸性物质有效降低了堆肥的氮素和NH_3-N损失,其中以添加磷肥效果最好.堆肥结束时,各处理GI均达到80%以上,达到了腐熟的要求.

Understanding the effects of acidic materials on the N transformations becomes of critical importance to choose the additives with preserving nitrogen during the manure composting. A 40 d static composting experiment was conducted in the laboratory to explore the effects of acidic materials on changes of temperature,pH,EC（ electrical conductivity）,GI（ germination index）,N compounds and TOC（ total organic carbon） during the composting of pig manure and wheat straw. Three acidic materials were selected as the additives,including phosphate fertilizer（ P）,rotten apples（ A） and vinegar（ V）. The results showed that the duration with temperature higher than 50℃ in four treatments all exceeded ten days and reached the health standard of high temperature composting.The addition of phosphate fertilizer delayed the time of the pile entering into the high temperature stage,decreased the pH,and increased the EC during the whole composting. On a mass basis,53. 1%,36. 2%,46. 5% and 41. 5% of original amount of N in CK,P,A and V were lost during the first 16 d,but there was still 20% N loss during 16-24 d in P and V treatments. The NH3-N loss accounted for 26. 0%,11. 8%,21. 5% and 20. 2% of the N loss. The addition of acidic materials effectively reduced the N loss and the emissions of NH3,and the phosphate fertilizer showed the best effect. In the end of composting,the GI all exceeded 80%,and met maturity requirements.