Effects of Different Phosphorus Application Amounts on Yield of Maize and Soil Phosphorus Content in Hetao Irrigation District of Inner Mongolia

[Objective]The research aimed to study the effects of different phosphorus application amounts on the yield of maize and soil phosphorus content in Hetao irrigation district of Inner Mongolia. [Method] By using field experiments and indoor chemical analysis and biological statistics,two year's experiments of different phosphorus application amounts were conducted in Wuyuan County. [Result]Phosphorus application significantly increased maize yield. Phosphorus use efficiency,agronomic efficiency and economic benefits showed a gradual decrease with the increase of phosphorus fertilizer. Three kinds of phosphorus forms in soil showed Olsen- P CaCl2- P DTP,which showed quadratic curve upward trend with the increase of phosphorus fertilizer. [Conclusion]The economic P2O5application amount was 150 kg/hm2in Hetao irrigation district,producing 100 kg grains absorbed about 0. 77 kg phosphorus. Residual phosphorus in soil increased with increase of phosphorus fertilizer.