秸秆还田方式对东北水稻土理化性质及微生物群落的影响

【目的】研究秸秆还田方式对东北黑土理化性质及微生物群落的影响。【方法】试验周期为2019年12月至2021年10月，秸秆还田采用2种方式： 秸秆直接还田+微生物菌剂WJ(strawdirect return+microbial agent WJ;MD)，秸秆堆肥还田+微生物菌剂WJ(straw compost return +microbial agent WJ;MC)。分析土壤肥力、酶活和微生物群落。【结果】分析两种方式土壤有机质(SOM)、腐殖酸(HS)和富里酸有机碳(FA-C)含量，发现秸秆直接还田+微生物菌剂WJ比秸秆堆肥还田+微生物菌剂WJ分别增加2.28g/kg、7.82g/kg和5.26g/kg。土壤铵态氮(NH4⁺-N)、速效磷(AP)略高于秸秆堆肥还田+微生物菌剂WJ，均在6月份达到峰值。胡敏酸有机碳(HA-C)含量下降。此外，土壤脲酶、转化酶、纤维素酶活性和碱性磷酸酶活性对比发现，秸秆直接还田+微生物菌剂WJ比秸秆堆肥还田+微生物菌剂WJ分别高8.55%、15.46%、4.35%和6.19%。高通量测序结果显示，秸秆直接还田+微生物菌剂WJ中细菌和真菌的多样性均比秸秆堆肥还田+微生物菌剂WJ丰富。其中Anaerolinea、Bacteroidetes、Pseudomonas为优势细菌，Tausonia、Mrakia、Mrakiella为优势真菌。【结论】秸秆直接还田+微生物菌剂WJ比秸秆堆肥还田+微生物菌剂WJ更有利于土壤有机质、腐殖酸、土壤酶活性和微生物多样性的增加，这说明秸秆添加WJ菌剂直接还田可以减少有机养分的流失，保持田间土壤肥力。

Effect of straw returning method on physicochemical properties and microbial community of paddy soil in Northeast China

Objective] To investigate the effect of straw returning method on physical and chemical properties and microbial community of black soil in Northeast China. Methods] The experiment was carried out from December 2019 to October 2021. Two ways of straw returning were adopted:direct straw returning+microbial agent WJ (hereinafter referred to as MD) and straw composting before returning+microbial agent WJ (hereinafter referred to as MC). Soil fertility, enzyme activities, and microbial community were analyzed. Results] The content of soil organic matter, humus and fulvic acid carbon was 2.28 g/kg, 7.82 g/kg and 5.26 g/kg, respectively, higher in MD than in MC. Content of soil ammonium nitrogen and available phosphorus in MD was slightly higher than that in MC, which peaked in June. Content of humic acid carbon decreased. In addition, the activities of urease, sucrase, cellulase and alkaline phosphatase in soil were 8.55%, 15.46%, 4.35% and 6.19% higher in MD than in MC, respectively. High-throughput sequencing results showed that the diversity of bacteria and fungi in MD was higher than that in MC. The dominant bacterial genera were Anaerolinea, Bacteroidetes and Pseudomonas, while Tausonia, Mrakia and Mrakiella dominated the fungi. Conclusion] MD was conducive to the increase of soil organic matter, humus, enzyme activities and microbial diversity as compared with MC, suggesting that addition of WJ into straw can reduce the loss of organic nutrients and maintain the fertility of the soil in the field.