Effect of different base fertilizers on soil microbial community diversity in cucumber rhizosphere

Genetic diversity and functional diversity of soil microbial community in cucumber rhizosphere as affected by different base fertilizers were studied by the Random Amplified Polymorphic DNA (RAPD) method and the BIOLOG technology, respectively. The results indicated that organic fertilizer at a rate of 75000 kg/ha or organic fertilizer (75000 kg/ha) with compound fertilizer at a rate of 300 kg/ha had higher effects on genetic diversity of soil microbial community under field conditions. Treatment of fertilizers as base application at level of 600 kg/ha resulted in decrease of DNA sequence richness index and diversity index of soil microbial communities, and the similarity coefficient of DNA sequence from soil microbial communities was the lowest compared with control. Organic fertilizer treatment was conducive to increasing DNA sequence diversity index and evenness index of soil microbial communities. Moreover, multivariate analysis of BIOLOG data indicated that organic fertilizer had a significant impact on sole carbon utilization pattern.