最小养分律是合理施肥必须遵守的原则之一。与作物生长发育有关的营养元素虽有很多种,但是其产量往往受土壤中相对含量最低的最小养分影响,即使其它养分有所增加,如果不补充最小养分,产量也不会得到提高。换言之,作物产量受土壤中数量最少的养分所控制,产量高低随这种养分的多少而变化,它反映了作物在土壤养分和种类和数量上供需的矛盾,在生产中具有重要的意义。五十年代,我国土壤80%以上缺氮,50%缺磷、30%缺钾。氮是当时限制产量的最小养分,施氮肥后获得了明显的增产效果。六十年代氮素营养比较充足,南、北方不少地区由于缺乏有效磷,施氮肥后不但不增产反而减产。当磷素供应不足,氨基酸的 The law of minimum nutrients is one of the principles that must be followed for proper fertilization. Although there are many kinds of nutrient elements related to crop growth and development, their yield is often affected by the minimum relative minimum content of nutrients in the soil. Even if other nutrients are increased, the yield will not increase if the minimum nutrients are not supplemented. In other words, crop yields are controlled by the least amount of nutrients in the soil. The level of yield varies with the amount of nutrients. It reflects the contradiction between supply and demand of crops in soil nutrients and species and quantity, which is of great significance in production. In the fifties, more than 80% of China’s soil nitrogen deficiency, 50% of phosphorus deficiency, 30% of potassium deficiency. Nitrogen was the minimum nutrient that limited production at that time, and a significant yield increase was achieved after applying nitrogen fertilizer. Nitrogen nutrition in the 1960s was relatively adequate. In many areas in the south and north, due to the lack of available phosphorus, not only nitrogen but no increase in output but yield reduction. When phosphorus is under supply, amino acids