减施化肥与不同有机肥配施对稻季土壤细菌群落结构的影响

为了研究减施化肥配施不同有机肥对稻麦轮作体系稻季土壤细菌群落结构的影响，采用Illumina高通量测序技术比较了单施化肥、配施菜籽饼和配施蚯蚓粪这3种施肥模式下稻季不同土层土壤环境因子、细菌群落结构变化特征。与单施化肥相比，配施有机肥显著提高各土层土壤有机质和电导率（EC）含量，配施菜籽饼增幅较大；显著增加各土层土壤氮磷钾养分含量，配施蚯蚓粪的土壤速效氮磷钾养分含量较高。配施有机肥提高土壤细菌Sobs指数和Shannon指数；前三位优势菌门，变形菌门（Proteobacteria）、酸杆菌门（Acidobacteria）、绿弯菌门（Chloroflexi）相对丰度分别达36.24%、18.30%、13.87%；配施有机肥对相对丰度小于1%的菌门影响较大。0-5cm土层土壤细菌群落结构主要受pH、TP影响；5-10cm土层土壤细菌群落结构主要受EC，TP、pH影响；10-15cm土层土壤细菌群落结构主要受TN、pH影响。配施有机肥通过改变土壤理化性质进而影响土壤细菌群落结构，特别是稀有菌群。

Effects of Reducing Chemical Fertilizer Combined with Application of Different Organic Fertilizers on Soil Bacterial Community Structure During Rice Season

In order to study the effects of combined application of different organic fertilizers on soil bacterial community structure during the rice season, Illumina high-throughput sequencing technology was used to compare the soil environmental factors and soil bacterial community structure in different soil layers, under three fertilization modes, namely chemical fertilizer, combined with rapeseed cake and earthworm manure. Compared with chemical fertilizer treatment, the treatments with combined application of organic fertilizers significantly increased the contents of SOM and EC in each soil layer, and the treatments with combined rapeseed cake increased SOM and EC significantly. The soil N, P and K contents were significantly increased in each soil layer. The soil N, P and K contents were highest in the treatment with combined application of wormcast. The treatments with combined application of organic fertilizers increased the soil bacterial Sobs index and Shannon index. Proteobacteria, Acidobacteria and Chloroflexi were the first three abundant in soil of the different treatments under phyla level, reached 36.24%, 18.30% and 13.87%, respectively. Combined application of organic fertilizer had a greater effect on the phyta whose relative abundance was less than 1%. Soil bacterial community structure in the 0-5cm soil layer was greatly affected by soil pH and TP, while the soil bacterial community structure in the 5-10cm soil layer was mainly affected by EC, pH and TP, and the soil bacterial community structure in the 10-15cm soil layer was greatly affected by soil TN and pH. Combined application of organic fertilizer affects soil bacterial community structure, especially rare bacteria, by changing soil physical and chemical properties.