高量秸秆还田配施芽孢杆菌对沙化土壤细菌群落及肥力的影响

Effect of High⁃volume Straw Returning and Applying Bacillus on Bacterial Community and Fertility of Desertification Soil

探讨高量秸秆还田模式协同配施芽孢杆菌等功能菌群对沙化土壤的培肥潜能,解析土壤碳氮磷组分和菌群功能活性的变化特征,可为高效提升沙化土壤肥力提供依据.采用随机区组试验,设置秸秆不还田(CK)、高量还田梯度分别为6.00 kg·m^(-2)(ST1)、12.00 kg·m^(-2)(ST2)、24.00 kg·m^(-2)(ST3)、6.00 kg·m^(-2)+芽孢杆菌(SM1)、12.00 kg·m^(-2)+芽孢杆菌(SM2)和24.00 kg·m^(-2)+芽孢杆菌(SM3)这7个处理组.利用16S rRNA高通量测序技术分析细菌多样性和群落结构,土壤农化分析方法测定土壤化学性质.结果发现:①高量秸秆还田协同配施芽孢杆菌显著降低土壤细菌群落α多样性;②高量秸秆还田单一模式显著富集变形菌门,降低放线菌门的相对丰度,配施芽孢杆菌对细菌群落结构变异性的影响更显著,在属水平上表现为假单胞菌、罗河杆菌和芽孢杆菌等有益菌属的相对丰度显著增加;③基于FAPROTAX的功能预测发现:高量秸秆还田配施芽孢杆菌显著提高了土壤菌群对有机物质的分解潜力和氮组分转化潜力;④与对照相比较,高量秸秆还田配施芽孢杆菌显著提升了ω(SOM)、ω(TP)和ω(AP),分别提高了31.20~32.75 g·kg^(-1)、0.11~0.18 g·kg^(-1)和29.69~35.09 mg·kg^(-1).因此,高量秸秆还田配施芽孢杆菌可显著提升沙化土壤有机质与磷组分含量、细菌功能活性与有益菌属丰度,对旱区沙化中低产田地力快速提升具有重要意义.

This study was conducted to explore the fertilization potential of the high⁃volume straw returning mode in cooperation with Bacillus and other functional flora on desertification soil and to analyze the changing characteristics of soil carbon,nitrogen,and phosphorus components and functional activities of flora,so as to provide a basis for efficiently improving desertification soil fertility.A randomized block experiment was conducted,setting straw not returning to field(CK)and high⁃volume straw returning of 6.00 kg·m^(-2)(ST1),12.00 kg·m^(-2)(ST2),24.00 kg·m^(-2)+(ST3),6.00 kg·m^(-2)+Bacillus(SM1),12.00 kg·m^(-2)+Bacillus(SM2),and 24.00 kg·m^(-2)+Bacillus(SM3).In this study,we conducted a randomized block experiment to investigate the effect of the treatment for soil microbial and nutrient contents using 16S rRNA high⁃throughput sequencing and soil biochemical properties analysis.Our results showed that:①theαdiversity of the soil bacterial community was significantly reduced by the combination of high⁃volume straw returning and Bacillus application.②The single mode of high⁃volume straw returning significantly enriched Proteobacteria and decreased the relative abundance of Actinobacteriota,and the effect of the combined application of Bacillus on the variability of bacterial community structure was more significant.At the genus level,the relative abundance of beneficial bacteria such as Pseudomonas,Rhodanobacter,and Bacillus increased significantly.③The functional prediction based on FAPROTAX found that the high⁃volume straw returning combined with Bacillus could significantly improve the decomposition potential of soil flora to organic substances and the transformation potential of nitrogen components.④Compared with that in the control,the application of Bacillus with high⁃volume straw returning significantly increased the contents of soil organic matter,total phosphorus,and available phosphorus by 31.20⁃32.75 g·kg^(-1),0.11⁃0.18 g·kg^(-1),and 29.69⁃35.09 mg·kg^(-1),respectively.In conclusion,the application of Bacillus in the sand⁃blown area with a high⁃volume straw returning can notably improve the contents of soil organic matter and phosphorus components,the functional activity of bacteria,and the abundance of beneficial bacteria,which is of great significance to the rapid improvement of soil fertility in the middle⁃and low⁃yield fields in arid areas.