采用PCR-DGGE克隆测序技术，分析沼液连续施用水稻油菜轮作耕层土壤细菌群落结构、丰富度指数和多样性指数等。通过DGGE图谱分析得出，沼液连年施用不利于丰富土壤细菌群落多样性，当连续3 a沼液施用总量控制为339.31～396.81 t/hm2时，细菌群落多样性增加，种群功能丰富、信息复杂、种群稳定，过高或过低施用沼液都会显著降低细菌群落多样性；通过UPGMA分析表明，长期连续施用沼液后土壤细菌遗传相似性降低，细菌种群结构变化越来越大。

PCR-DGGE cloning sequencing technology was used to analyze and compare the bacterial community structure，richness index and diversity index of soil bacteria in rice-rape rotation cultivation layer. Through the analysis of the DGGE profiles concluded that biogas slurry in successive years application does not favor the rich soil bacterial community diversity， when biogas slurry application of total amount controled in 339.31~396.81 t/hm2， bacterial community diversity increases， bacterial population feature rich， complicated information and population stable， too high or too low application of biogas slurry can significantly reduce the bacterial community diversity; According to UPGMA analysis， the genetic similarity of soil bacteria decreased after long-term continuous application of biogas slurry， and the bacterial population structure changed bigger and bigger.

S154.32