米糠、锯末与蛋鸡粪堆肥过程中氮素的变化特征

摘要

探讨米糠、锯末与蛋鸡粪堆肥过程中氮素的变化特征,旨在为制定蛋鸡粪堆肥规模化生产中减少氮素损失、减少氨气挥发的调控措施提供科学依据.试验设4个处理,蛋鸡粪-米糠、蛋鸡粪-锯末,隔天翻堆1次；蛋鸡粪-米糠-锯末、蛋鸡粪-锯末,每天翻堆1次,定期测定物料理化指标.研究表明,堆肥过程中,铵态氮向硝态氮转化受抑制,氮素转化以有机氮与铵态氮间的相互转化以及铵态氮以氨气形式挥发为主,铵态氮主要以氨气形式挥发造成全氮损失.氮素转化与损失与堆肥温度、pH、O2等环境参数有关,高温、高pH促进氨气挥发；充足的氧气可促进铵态氮向微生物量态氮(有机氮)转化.这些参数主要受堆体结构对堆肥氧气供应和有机质分解的影响.因此,可以尝试在米糠和锯末中添加来源广泛的秸秆类辅料,通过改善堆体结构(容重)来减少氮素损失.%This study was conducted to investigate the nitrogen transformations during the layer-hen manure composting with rice bran and sawdust.Four treatments include,layer manure-rice bran and sawdust turning by 2 days,layer manure-rice bran-sawdust and layer manure-sawdust turning per day.The results showed that the conversion of ammonium nitrogen to nitrate nitrogen was inhibited,so the mutual transformation between organic nitrogen and ammonium nitrogen and ammonium nitrogen to ammonia emission were the main way in nitrogen transformation,and the latter resulting in nitrogen losses.The transformation and losses of nitrogen was related to environment parameters,such as pile temperature,pH and oxygen.High pile temperature and pH(T＞60℃ 、pH＞8 or T＞70℃ 、pH＞9) increased ammonia emission,while ample oxygen(＞5 ％) could promote the conversion of ammonium nitrogen to microbial biomass nitrogen(organic nitrogen).Therefore adding rice straw in rice bran-sawdust-layer manure composting could reduce nitrogen losses by improvement of pile structure.