PDF(Pubmed)
Abstract：
Under a full straw returning system, the relationship between soil bacterial community diversity and straw decomposition, yield, and the combined application of slow-release nitrogen and urea remains unclear. To evaluate these effects and provide an effective strategy for sustainable agricultural production, a 2-year field positioning trial was conducted using maize as the research object. Six experimental treatments were set up: straw returning + no nitrogen fertilizer (S1N0), straw returning + slow-release nitrogen fertilizer:urea = 0:100% (S1N1), straw returning + slow-release nitrogen fertilizer:urea = 30%:70% (S1N2), straw returning + slow-release nitrogen fertilizer:urea = 60%:40% (S1N3), straw returning + slow-release nitrogen fertilizer:urea = 90%:10% (S1N4), and straw removal + slow-release nitrogen fertilizer:urea = 30%:70% (S0N2). Significant differences (p < 0.05) were observed between treatments for Proteobacteria, Acidobacteriota, Myxococcota, and Actinobacteriota at the jointing stage; Proteobacteria, Acidobacteriota, Myxococcota, Bacteroidota, and Gemmatimonadota at the tasseling stage; and Bacteroidota, Firmicutes, Myxococcota, Methylomirabilota, and Proteobacteria at the maturity stage. The alpha diversity analysis of the soil bacterial community showed that the number of operational taxonomic units (OTUs) and the Chao1 index were higher in S1N2, S1N3, and S1N4 compared with S0N2 at each growth stage. Additionally, the alpha diversity measures were higher in S1N3 and S1N4 compared with S1N2. The beta diversity analysis of the soil bacterial community showed that the bacterial communities in S1N3 and S1N4 were more similar or closely clustered together, while S0N2 was further from all treatments across the three growth stages. The cumulative straw decomposition rate was tested for each treatment, and data showed that S1N3 (90.58%) had the highest decomposition rate. At the phylum level, straw decomposition was positively correlated with Proteobacteria, Actinobacteriota, Myxococcota, and Bacteroidota but significantly negatively correlated with Acidobacteriota. PICRUSt2 function prediction results show that the relative abundance of bacteria in soil samples from each treatment differed significantly. The maize yield of S1N3 was 15597.85 ± 1477.17 kg/hm2, which was 12.80 and 4.18% higher than that of S1N1 and S0N2, respectively. In conclusion, a combination of slow-release nitrogen fertilizer and urea can enhance the straw decomposition rate and maize yield by improving the soil bacterial community and structure within a full straw returning system.
摘要：
在一个完整的秸秆还田系统下,土壤细菌群落多样性与秸秆分解的关系,产量，缓释氮和尿素的联合应用尚不清楚。为了评估这些影响，并为可持续农业生产提供有效的策略，以玉米为研究对象，进行了为期2年的田间定位试验。设置了6个实验处理:秸秆还田+不施用氮肥(S1N0),秸秆还田+缓释氮肥:尿素=0:100%(S1N1),秸秆还田+缓释氮肥:尿素=30%:70%(S1N2),秸秆还田+缓释氮肥:尿素=60%:40%(S1N3),秸秆还田+缓释氮肥:尿素=90%:10%(S1N4),秸秆去除+缓释氮肥:尿素=30%:70%(S0N2)。在变形杆菌的处理之间观察到显着差异（p<0.05），酸杆菌,粘球菌,和拔节期的放线菌；变形杆菌，酸杆菌,粘球菌,拟杆菌,和双峰在抽检阶段；和拟杆菌，Firmicutes,粘球菌,Methylomirabilota,和成熟阶段的变形杆菌。土壤细菌群落的α多样性分析表明，在每个生长阶段，S1N2，S1N3和S1N4中的操作分类单位数（OTU）和Chao1指数均高于S0N2。此外,S1N3和S1N4中的α多样性度量高于S1N2。土壤细菌群落的β多样性分析表明，S1N3和S1N4中的细菌群落更相似或更紧密地聚集在一起，而S0N2在三个生长阶段的所有处理都进一步。对各处理的累计秸秆分解率进行了测试,数据表明，S1N3(90.58%)的分解率最高。在门一级，秸秆分解与变形杆菌呈正相关，放线菌,粘球菌,和拟杆菌，但与酸杆菌呈显著负相关。PICRUSt2功能预测结果表明，各处理土壤样品中细菌的相对丰度差异显著。S1N3的玉米产量为15597.85±1477.17kg/hm2，分别比S1N1和S0N2高12.80和4.18％。总之,缓释氮肥和尿素的组合可以通过改善秸秆还田系统中土壤细菌群落和结构来提高秸秆分解率和玉米产量。
