试验目的、方法黄淮海平原具有很大的增产潜力,但土壤肥力低,氮、磷养分供应不足是农业生产上的一个主要限制因素。对不同土壤主要作物使用氮、磷化肥效应的最佳方案尚未充分研究和论证,同时在化肥使用上相当浪费,利用率很低。如何根据不同土壤的性质、养 PURPOSE AND METHOD The Huang-Huai-Hai Plain has great potential for yield increase, but its low soil fertility and insufficient supply of nitrogen and phosphorus nutrients are one of the major limiting factors in agricultural production. The best solution to the effects of nitrogen and phosphorus fertilizers on different soil main crops has not yet been sufficiently studied and demonstrated. At the same time, it is quite wasteful to use chemical fertilizers and the utilization rate is very low. How to raise the soil according to different nature