| With incubation and pot experiments, an irrigated desert soil was amended with equal amount of phosphorus (P), sulfur (0.05%, 0.15%, and 0.45%), biological fertilizer (0.25%, 0.50%, and 1.00%), organic fertilizer (0.50%, 1.00%, and 2.00%), and wheat straw (1.00%, 2.00%, and 4.00%). The purpose was to investigate the change patterns of soil microbial biomass P and Olsen P as well as their relationships with P uptake by wheat. The results showed that the content of soil microbial biomass P was significantly higher in the soil treated with different modified supplements than that with control (sole P application), and increased with increasing the proportion of addition. At 16 days, the soil microbial biomass P content reached the maximum value. Treatment OM22.00, B21.00, WS24.00, and S20.45 increased by 34.66%, 34.52%, 28.19%, and 23.89%, respectively. When soil Olsen P was lower than 90 mg·kg-1, soil microbial biomass P increased with the increase in soil Olsen P. At the 16th and 30th day of culture, the P uptake of wheat plants was also significantly correlated with soil microbial biomass P. In general, the application of P fertilizer combined with organic fertilizer or biological fertilizer promoted microbial biomass P, and improved the bioavailability of P. It is of great significance for the efficient utilization of P in irrigated desert soil. |