前言自一九六二年起,我所就开展了关于小麦氮肥施用方法的试验研究工作,其主要内容包括不同氮肥品种、氮肥不同用量以及施肥时期和方法对小麦增产效果的试验研究。一九七○年以前的试验研究结果,概括起来有:1.等氮的条件下,以硝铵对小麦的增产效果最大,硫铵次之,尿素第三。2.小麦单产由二百多斤的低产水平提到四百到五百斤的中产水平,在施足基肥,精细整地,做到苗齐、苗匀和有水灌溉的条件下,增施氮素化肥似为主要支配因子,以每亩施三十斤左右硝铵(折合十斤二两纯氮)最为经济有 Preface Since 1962, I conducted a pilot study on the application of wheat nitrogen fertilizers. The main contents include the experimental study on the effects of different nitrogen fertilizers, different amounts of nitrogen fertilizers and the fertilizing time and method on wheat yield. The results of the pilot study before 1970 are summarized as follows: 1. Under the conditions of nitrogen, the yield of wheat with ammonium nitrate is the highest, ammonium sulfate is the second, and urea is the third. 2. Wheat yield refers to the middle level of 400-500 jin from a low yield level of 200 kilograms. Under the condition of applying sufficient amount of base fertilizer and finely adjusting the soil, so that seedling, seedling and water are irrigated, nitrogen Fertilizer seems to be the main dominant factor to apply about thirty pounds per acre ammonium nitrate (equivalent to twenty pounds of pure nitrogen) is the most economical