磷肥用量对河套灌区玉米产量·土壤磷含量的影响

[目的]为了探讨不同磷肥用量对河套灌区玉米产量、土壤有效磷含量的影响。[方法]采用田问试验和室内分析化验相结合的方法，在内蒙古五原县连续2年进行不同磷肥用量试验。[结果]施磷可明显提高玉米产量。随着磷肥用量的增加，磷肥利_用率、农学效率、经济效益均呈逐渐下降趋势，土壤中3种磷素形态表现为Olsen-P〉CaCl2-P〉DTP。随着磷肥施肥量的增加，土壤Olsen—P、CaCl2-P、DTP呈二次型曲线增加趋势。[结论]河套灌区种植玉米经济施磷量为150kg／hm^2，生产100kg籽实吸磷量平均在0．77kg左右，随着施磷量的增加，土壤磷残留逐渐增加。

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

[ Objective ] The research aimed to study the effects of different phosphorus application amounts on the yield of maize and soil phos- phorus 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 applica- tion 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 〉 CaC12 - P 〉 DTP, which showed quadratic curve upward trend with the increase of phosphorus fertilizer. [ Conclusion] The economic P205 application amount was 150 kg/hm2 in Hetao irrigation district, producing 100 kg grains absorbed about 0. 77 kg phosphorus. Residual phosphorus in soil increased with increase of phosphorus fertilizer.