水稻-油菜周年耕作方式对土壤微生态的影响

为探索土壤微生态对稻-油系统周年耕作方式的响应机制,利用湘北洞庭湖区长期免耕直播土壤,设置稻-油轮作试验,通过比较双免耕双直播和旋耕抛栽土壤中酶活性、微生物数量、群落多样性和菌群功能等指标的差异,研究不同耕作方式对土壤微生态的影响.宏基因组测序表明,细菌群落在2种耕作方式下组成相似,双免耕双直播下细菌多样性更高;真菌群...

Effect of Rice-rapeseed Annual Tillage Patterns on Soil Microecology

To explore the response mechanism of soil microecology to rice-rapeseed system annual tillage patterns, a rice-rapeseed rotation experiment was conducted on the long-term no-tillage direct seeding soil of Dongting Lake area of north Hunan. The differences of soil enzyme activity, microorganism quantity, diversity and microbial community function between the double no-tillage direct seeding (DNT) and double rotary-tillage transplantation (DT) were compared to illustrate the effects of different tillage patterns on soil microecology. The metagenomic sequencing showed that there were similar bacterial types under the two patterns, the bacterial diversity was higher under DNT, but the fungal diversity under DT was higher. Function analysis illustrated that the relative abundance of aerobic and facultative anaerobic prokaryotes was higher in DNT; the relative abundance of prokaryotes related to nitrogen metabolism was higher in DNT, while the relative abundance of prokaryotes related to carbon metabolism was higher in DT. The number of culturable bacteria, fungi, actinomycetes and nitrifying bacteria in DNT soil was significantly lower than that in DT, while the number of ammonifying bacteria was significantly increased. Enzyme activity analysis showed that urease activity of DNT was 58.12% higher than that of DT, while the activities of invertase, phosphatase and cellulase decreased by 28.57%, 11.00% and 57.73%, respectively. The results indicated that the DNT rice-rapeseed rotation system was beneficial to improve the bacteria diversity, and the relative abundance of aerobic and facultative anaerobic prokaryotes, and was conductive to the transformation and utilization of nitrogen in the soil. The study provides a basis for the selection of reasonable tillage patterns of rice-rapeseed system in Dongting Lake area.