玉米氮磷最佳施肥比例与报酬递减律研究

Study on the Application Ratio of Nitrogen and Phosphate and Law of Diminishing Returns for Corn

采用氮磷施肥比例试验与最佳氮磷比例条件下施肥量试验相结合的设计方法,对平衡土壤养分类型和不平衡土壤养分类型玉米的边际产量变化规律进行了研究。结果表明,2种养分类型的土壤种植玉米,在最佳氮磷施肥比例与最大施肥量条件下,玉米边际产量基本为一常数;超过最大施肥量后,玉米的边际产量显著降低,不同年份和不同区域平衡与不平衡土壤养分类型种植玉米均具有同样的规律,并非经典理论所表述的随着施肥剂量的增加呈递减规律。

In the paper, adopting the approch which the trial of application ratio and rate of N and P was devised in the same experiment, the changing rule of the marginal productions on corn was studied with the types of balanced and unbalanced soil nutrient supply.Rmult indicated that in the two types of corn-growing soil, the marginal production of corn was basicaly a constant in the optimum application ratio and maximum application rate of N and P, and declined significantly after the maximum application rate of N and P. It showed the same rule in different years and areas.