Although composting is a very effective way to dispose agricultural wastes, its development is greatly limited by the low compost quality and greenhouse gas emissions. At present, there is a lack of effective means to solve these two problems simultaneously. Here, the effects of three additives of compound microbial agent, biochar and biochar carried microbial agent on the composting performance, nitrogen transformation, greenhouse gas and ammonia emissions, and bacterial communities were investigated in sheep manure composting during 28 days. Results showed that biochar carried microbial agent prolonged the thermophilic stage and promoted compost maturity. At the same time, it was confirmed by the increase of the decomposition of organic nitrogen and the transformation of NH₄⁺-N to NO₃⁻-N. Besides, adding biochar carried microbial agent decreased CH₄, NH₃ and N₂O emissions by 65.23%, 42.05% and 68.64%, respectively. The gas emissions were mainly correlated to Chloroflexi, Myxococcota, Acidobacteriota, Firmicutes, and Gemmatimonadota. Redundancy analysis showed that EC and TKN were closely related to bacterial community. Therefore, biochar carried microbial agent is recommended as an effective additive to enhance compost quality and reduce gas emissions during sheep manure composting.

Graphical Abstract

中文翻译：

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生物炭载菌剂对羊粪堆肥过程中堆肥质量、温室气体排放和细菌群落的影响

虽然堆肥是一种非常有效的农业废弃物处理方式，但其发展受到堆肥质量低和温室气体排放的极大限制。目前，缺乏同时解决这两个问题的有效手段。在此，考察了复合菌剂、生物炭和生物炭载菌剂三种添加剂对羊粪堆肥28天堆肥性能、氮转化、温室气体和氨排放以及细菌群落的影响。结果表明，生物炭携带菌剂延长了堆肥的高温阶段，促进了堆肥的成熟。同时，有机氮的分解增加和NH ₄ ⁺ -N向NO的转化也证实了这一点₃ ^- -N。此外，添加生物炭载菌剂可使CH ₄、NH ₃和N ₂ O排放量分别降低65.23%、42.05%和68.64%。气体排放主要与Chloroflexi、Myxococcota、Acidobacteriota、Firmicutes和Gemmatimonadota相关。冗余分析表明EC和TKN与细菌群落密切相关。因此，生物炭载菌剂被推荐作为一种有效的添加剂，以提高羊粪堆肥过程中的堆肥质量，减少气体排放。

图形概要