不同供磷水平对紫花苜蓿根际微生物功能多样性的影响

Exploring the metabolic functional diversity of Medicago sativa rhizosphere microorganisms at different levels of phosphorus supply can further our understanding of the mechanism of efficient fertilizer use by M. sativa. Applying the biolog method through field experiments, we investigated the metabolic characteristics of the M. sativa rhizosphere microbial community under five different levels of phosphorus supply. The results showed that the application of phosphorus fertilizer could significantly improve the metabolic activity of M. sativa rhizosphere microorganisms; the Simpson and Richness indexes reached maximum values when the phosphorus supply level was P3 (300 kg · hm- 2 ), which improved the utilization of different classified carbon sources by microorganisms. When the phosphorus fertilizer concentration was too high, it significantly reduced the Simpson index of the microbial community and also reduced the utilization of various carbon sources by microorganisms. Principal component analysis showed that there were significant differences in the utilization of different carbon sources by rhizosphere microorganisms at different levels of phosphorus supply. The smallest differences in the utilization of various carbon sources by the microbial community were observed at the highest level of phosphorus supply (P4, 450 kg·hm-2 ).