一、棉花早衰的主要原因１、棉花面积逐年扩大，多年连作，土壤中某些元素的贫乏，营养失调，导致棉花早衰。２、地膜覆盖栽培。据测定宽膜棉侧根着深只有８～１０ｃｍ，较露地棉浅４．３ｃｍ，较窄膜棉浅２．７ｃｍ。地膜覆盖后，土壤通透性差，根系分布浅，棉花前期根系生长 First, the main reason for premature aging of cotton 1, cotton area has expanded each year, even for many years, some of the elements in the soil is poor, malnutrition, leading to premature aging of cotton. 2, mulching cultivation. According to the determination of broad-film side of the cotton root deep only 8 ~ 10cm, 4.3 cm lighter than open cotton, thin film cotton shallow 2.7cm. After mulching, the soil permeability is poor, the root system is shallow and the root system grows in early cotton