论文摘要 |
Frequent tillage generally results in soil organic matter loss, microbial activity suppression, and soil structure deterioration. In this study, we have used polymerase chain reaction (PCR) based on 16/18S rRNA sequences, followed by denaturing gradient gel electrophoresis (DGGE) to assess the effect of different tillage managements on soil microbial populations. Soil samples were collected in June 2008 at depths of 0-10 cm and 10-20 cm at Luancheng Agroecosystem Experimental Station, Chinese Academy of Sciences. The three treatments with three replicates were: conventional tillage (CT), rotary tillage (RT) and no-tillage (NT), which represent the typical tillage systems in the North China Plain. Our results suggest that the soil micro-bial community structure varies under different tillage managements. The community diversities of bacteria were higher in soils under RT and NT than that under the CT in the 0-10 cm layer, whereas there was no significant difference in the community diversity of bacteria within the three treatments in the 10-20 cm layer soil. As for the soil fungi, the community diversities were obviously higher in soils under RT and NT than in the CT in both the 0-10 cm and 10-20 cm layers. These results indicate the sensitivity of soil microbial community to tillage and the necessity of considering the effects of agricultural managements on the soil microbial community when assessing changes in soil microbial community structure and diversity. |