钼磷养分对福建红壤稻田生物固氮的影响

he mineral nutrients in the soil affect the nitrogen fixation in paddy soil. In order to study the effect of molybdenum (Mo) and phosphorus (P) on nitrogen fixation of red paddy soil in Fujian province, the rice soil in Yongchun County of Quanzhou was selected as the study object. These treatments consisted of the control (CT), gradient separate Mo addition (LM, HM), gradient separate P addition (LP, HP) and gradient Mo and P composited (LM+LP, LM+HP, HM+LP, HM+HP). The experiment was carried out for a period of time, and then added C, Fe and N into the soil respectively, and the acetylene reduction method was used to study the activity of nitrogen-fixing enzymes in soil with different Mo-P gradient nutrients. The results showed that the addition treatment of HM and LP was beneficial to the promotion of micro-biological nitrogen fixation in the paddy soil, and higher P content might inhibit the nitrogen fixation rate. The addition of C could effectively promote the activity of soil nitrogen fixation in CT, HP, LM+LP, LM+HP, HM+LP treatments, especially CT soil. The addition of Fe stimulated the biological nitrogen fixation in each gradient soil. The addition of N was more favorable to the nitrogen fixation of HM soil. The results showed that the difference in soil nutrients concentrations was the main factor to change the activity of nitrogen-fixing enzymes.