对北方灌溉棉区来说,头水的早晚,对产量影响很大。那么,什么时候灌头水好呢?新疆生产建设兵团农一师在实践中体会到,头水要按照棉花的需水规律,结合土壤的质地、肥力、盐分、墒情及棉株长势长相,正确掌握灌水时机,真正把头水浇在棉花需水的节骨眼上。浇好头水有如下几个标准: 1.土壤含水量:依据0—40厘米土壤含水量下降速度来决定。质地粘重、肥力较高的稻茬棉田,每五天土壤含水量下降0.4—1%,开沟指标为15%,进水指标14.5%,灌水必须结束指标为14%, 沙质壤土、肥力中等的冬灌麦 For northern irrigated cotton areas, the head-water sooner or later has a huge impact on production. So, when irrigation is good? Xinjiang Production and Construction Corps Nongsiji learned in practice, the head of water in accordance with the law of the demand of cotton, combined with the texture of the soil, fertility, salt, moisture and cotton grow, correct Grasp the timing of irrigation, the real head water pouring cotton at the critical juncture. There are several standards for pouring a good head of water: 1. Soil moisture content: Determined according to the descending speed of 0-40 cm soil water content. Soil stickiness, high fertility of rice stubble field, every five days soil water content decreased 0.4-1%, ditching index of 15%, influent index 14.5%, irrigation must end indicator of 14%, sandy loam, fertility Medium winter wheat