一、概况七十年代以来,合理施肥向两个方面深入,其一是从化肥本身,按土壤和作物需缺,调节氮磷钾施用量和比例。改良剂型、研究合理的施肥期等。另一方面,则是从有机无机配合上,研究其配合的效果。国外一些学者也认为,提高化肥利用率,主要有四条:1、合理的有机无机配合。 I. Overview Since the 1970s, rational fertilization has deepened in two aspects. One is to adjust the amount and proportion of nitrogen, phosphorus and potassium applied from the fertilizer itself and according to the needs of soil and crops. Improve dosage forms, research and reasonable fertilization period. On the other hand, from the organic and inorganic coordination, the effect of its coordination. Some foreign scholars also believe that to improve fertilizer utilization, there are four main: 1, a reasonable organic and inorganic.