Jin Yu-Ting, Li Xian-Fan, Cai Ying, Hu Hong-Xiang, Liu Yun-Feng, Fu Si-Wei, Zhang Bo-Rui
Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention, College of Resources and Environment, Anhui Agricultural University, Hefei 230036, China.
Huan Jing Ke Xue. 2021 Aug 8;42(8):3985-3996. doi: 10.13227/j.hjkx.202012077.
Straw returning is an effective technique for improving soil fertility and maintaining crop productivity in agro-ecosystems. The effects of straw returning, when combined with chemical fertilizer, on soil nutrients, enzyme activity, and microbial community were explored in rice-rape rotation farmland in the Chaohu Area. We carried out a 4-year field experiment (2016-2020) and set up four treatments (no straw+no fertilization, CK; conventional fertilization, F; straw returning+conventional fertilization, SF; and straw returning+conventional fertilization minus 20%, SDF) to explore the key environmental factors affecting soil enzyme activity and microbial and fungal communities. The results showed that straw returning combined with chemical fertilizer could improve soil nutrient content, with the SF treatment resulting in the highest soil nutrient content. Compared with F, the SF treatment significantly increased the organic matter (OM) and total phosphorus (TP) content of the soil, by 7.94% and 24.07%, respectively, in rice seasons (<0.05), while the alkaline nitrogen (AN) content was significantly increased by 13.62% in rape seasons (<0.05). Compared with F, the SF treatment also significantly increased soil phosphatase and urease, by 28.54% and 24.13% in rice seasons and 38.97% and 30.70% in rape seasons, respectively (<0.05). Compared with F, SDF treatments significantly increased urease activity by 20.31% in rice seasons and 24.33% in rape seasons (<0.05). The results indicated that straw returning increased both the Chao1 and Shannon indices of soil bacteria in rice seasons, whereas decreased these indices in rape seasons. However, the Chao1 and Shannon index of the fungal community increased after straw returning. In terms of microbial community structure, the relative abundance of Proteobacteria in SF and SDF treatments increased by 8.22% and 7.88% in rice seasons and 18.53% and 5.68% in rape seasons, respectively, compared with the F treatment. Compared with F, the relative abundance of Chloroflexi in SF and SDF treatments increased by 12.00% and 11.25% in rice seasons and 15.02% and 8.43% in rape seasons, respectively. Compared with F, the relative abundance of Basidiomycota in SF and SDF treatments in rice seasons increased by 70% and 43.42% (<0.05), respectively, while ascomycetes in rape seasons increased by 69.79% and 43.72% (<0.05), respectively. In conclusion, straw returning combined with chemical fertilizer can improve soil nutrient content. Soil urease and phosphatase were more sensitive to straw returning. The compositional changes in the bacterial community of the soil were mainly affected by soil TP and available phosphorus (AP), whereas OM, AN, and pH were the main environmental factors causing changes in the fungal community composition. Consequently, straw returning can improve soil fertility and maintain ecosystem health.
秸秆还田是提高农业生态系统土壤肥力和维持作物生产力的有效技术。在巢湖地区的稻油轮作农田中，研究了秸秆还田与化肥配施对土壤养分、酶活性和微生物群落的影响。开展了为期4年（2016 - 2020年）的田间试验，设置了四个处理（不秸秆 + 不施肥，CK；常规施肥，F；秸秆还田 + 常规施肥，SF；秸秆还田 + 常规施肥减20%，SDF），以探究影响土壤酶活性以及微生物和真菌群落的关键环境因素。结果表明，秸秆还田与化肥配施可提高土壤养分含量，其中SF处理的土壤养分含量最高。与F处理相比，SF处理显著提高了水稻季土壤有机质（OM）和全磷（TP）含量，分别提高了7.94%和24.07%（<0.05），而油菜季碱解氮（AN）含量显著提高了13.62%（<0.05）。与F处理相比，SF处理还显著提高了土壤磷酸酶和脲酶活性，水稻季分别提高了28.54%和24.13%，油菜季分别提高了38.97%和30.70%（<0.05）。与F处理相比，SDF处理显著提高了水稻季脲酶活性20.31%，油菜季提高了24.33%（<0.05）。结果表明，秸秆还田增加了水稻季土壤细菌的Chao1和Shannon指数，而降低了油菜季的这些指数。然而，秸秆还田后真菌群落的Chao1和Shannon指数增加。在微生物群落结构方面，与F处理相比，SF和SDF处理中变形菌门在水稻季的相对丰度分别增加了8.22%和7.88%，在油菜季分别增加了18.53%和5.68%。与F处理相比，SF和SDF处理中绿弯菌门在水稻季的相对丰度分别增加了12.00%和11.25%，在油菜季分别增加了15.02%和8.43%。与F处理相比，SF和SDF处理在水稻季担子菌门的相对丰度分别增加了70%和43.42%（<0.05），而在油菜季子囊菌门分别增加了69.79%和43.72%（<0.05）。总之，秸秆还田与化肥配施可提高土壤养分含量。土壤脲酶和磷酸酶对秸秆还田更为敏感。土壤细菌群落组成变化主要受土壤TP和有效磷（AP）影响，而OM、AN和pH是导致真菌群落组成变化的主要环境因素。因此，秸秆还田可提高土壤肥力并维持生态系统健康。
