宁夏南部山区旱地冬小麦氮磷肥效及最佳用量的研究

应用二次饱和D-最优设计研究了宁夏南部山区旱地冬小麦氮磷肥的合理施用量．结果表明，宁夏南部山区旱地施肥量严重不足，化肥增产潜力巨大．在春旱严重的情况下，磷肥的增产作用大于氮肥，氮磷肥配合施用增产效果更加显著，比不施肥时增产1410kg／hm^2，比习惯质种植增产810kg／hm^2，增产率为46．4％．最佳产量为2490kg／hm^2时，施氮量为93．6kg／hm^2，施磷量（P2O5）为108．9kg／hm^2，产投比为3．4：1，效益显著．

Study on the Effect and Optimized Amount of N and P Fertilizers to Winter Wheat in Rainfed Land in the Southern Ningxia

The optimized designing of N, P was adopted to study the optimized amounts of N, P to winter wheat. The results indicated that the amounts of applied fertilizers in southern Ningxia were serious insufficient. Applied fertilizers have huge latent for increasing the yield of wheat. In the dry years, phosphorus fertilizer takes higher effect than Nitrogen fertilizer. N and P matching can increase the yield 1 410 kg/hm^2 compared with CK, and 810 kg/hm^2 compared with the usual cultivation. The rate of growth was 46. 4 %. The optimum application of pure N should be 93. 6 kg/hm^2, and P2O5 should be 108. 9 kg/hm^2. The optimum yield of wheat was 2 490 kg/hm^2. The rate of production and investment was 3. 4 to 1. That achieved notable benefit.