Effects of cultivation modes on soil enzyme activities and bacterial community structures in the cucumber rhizosphere

To solve the problem of soil degradation with the increase of continuous cropping years, changes of rhizosphere soil enzyme activities and bacterial community structures under different cultivation modes were studied. The cultivation modes (accompany and intercropping) were set up with cucumber as the main crop. Wheat and oats were accompanied with cucumber, respectively, and Chinese onion, Chinese cabbage and celery were intercropped with cucumber, respectively. The results suggest that the soil catalase activities are increased when cucumber is cultivated with wheat, oats and Chinese onion, the soil urease activities are increased under the celery treatment, and the soil invertase activities are increased significantly in all cultivation modes. The results of the cloning and sequencing of DGGE bands amplified from cucumber rhizospheric soil samples show a high homology to uncultured bacterial species. The bands in cucumber rhizosphere soil are affiliated with Alphaproteobacteria, Betaproteobacteria, Sphingobacteria and Gemmatimonadetes. This study shows that soil enzyme activities and soil bacterial community structures are influenced by different cultivation modes, the soil environment is influenced by the cultivation modes, and the accompanied with wheat is a better mode of cucumber.