利用甘薯、棉花、夏豆等晚熟作物的茬口种小麦,是扩大小麦面,提高小麦总产的一条熟经验。但由于这部分田错过了播种适期,晚造成小麦生长发育所积温不足;加之这些晚作物对土壤养分消耗大。致使这部分麦田的麦前期生长发育不良,穗率减少,穗粒数和千重下降,成为小麦生产的“低产田 The use of sweet potato, cotton, summer beans and other late crop of stubble wheat species, is to expand the wheat noodles, wheat production to improve a ripe experience. However, due to this part of the field missed the sowing period, resulting in late growth and development of wheat accumulated lack of temperature; combined with these late crops on soil nutrient consumption. As a result, the early wheat growth and malformation in this part of wheat field decreased, the spike rate decreased,