麦后移栽棉花是我国长江下游棉区特有的栽培方式,1982—1985年的研究如下: ①上海地区正常年景,棉花产量对土壤肥力的依存率约75％,金山、青浦等县青紫泥地区仅60—65％。故棉花施肥能提高单位面积的产量。②棉花的产量受氮素的制约,但增产幅度不仅和氮素用量有关,还和施肥方式(棉花需肥期和供氮期是否同步)有关。麦后移栽棉按麦垅直播棉花施肥方式施肥的(每亩纯氮9公斤以上),增产幅度低,在梅雨期长、降水量多的年份,还会出现肥害,造成减产。 Transplanting wheat after transplanting is the unique cultivation method of cotton area in the lower reaches of the Yangtze River in our country. The research from 1982 to 1985 are as follows: ①In normal years in Shanghai, cotton yield depends on soil fertility about 75% The area is only 60-65%. Therefore, cotton fertilization can increase the yield per unit area. ② The yield of cotton is restricted by nitrogen, but the rate of yield increase is not only related to the amount of nitrogen, but also to the way of fertilization (whether the cotton need fertilizer and nitrogen supply are synchronized). Transplanting wheat after transplanting wheat According to direct seeding of wheat straw fertilizing fertilizers (per acre more than 9 kg of pure nitrogen), the rate of increase is low, in the long rainy season, precipitation and more years, there will be fertilizer damage, resulting in reduced production.