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1、氮、磷、钾等化肥的配合使用:目前我国生产的化肥品种较少,有效成分单一。为促进作物生长发育对多种营养成分的需要,不同化肥的配合施用是十分重要的。作物生长有规律,按生育期有比例地吸收各种营养元素,各种营养元素对作物的生长发育所起的生理作用,又是同等重要而不可互相替代。因此,根据土壤中养分不同情况确定不同化肥的配合施用,使营养元素之间比例协调,互相增进肥效。有利于作物丰产。相反,施肥不当致使营养比例失调,就会限制肥效的发挥,影响丰产。2、报酬递减律:在一定的条件下,随着化肥用量的增加,产量亦增加,但用量超过一定的限度就会造成减产。报酬递减是在技术条件这个前提下的客观现象。在目前化肥供应量不断增加的情况下,我们必须考虑施
1, with the use of nitrogen, phosphorus, potassium and other fertilizers: At present, China produces fewer varieties of fertilizers, a single active ingredient. In order to promote crop growth and development of a variety of nutrients, the application of different fertilizers is very important. Crop growth regularly, according to the proportion of growth period to absorb a variety of nutrients, a variety of nutrients on the physiological role of crop growth and development, is equally important and can not be replaced each other. Therefore, according to the soil nutrients in different situations to determine the application of different fertilizers, so that the proportion of nutrients coordinated between each other to promote fertilizer efficiency. Conducive to crop yield. On the contrary, improper fertilization resulting nutrition imbalance, it will limit the effectiveness of fertilizer, affecting high yield. 2, the law of diminishing returns: Under certain conditions, with the increase in the amount of fertilizer, production also increased, but the amount exceeds a certain limit will result in reduced production. Decreasing returns is an objective phenomenon under the premise of technical conditions. In the current situation of increasing supply of fertilizer, we must consider Shi