超高产夏玉米耗水特性与灌水指标的研究

Study on Water Consumption Characteristic and Irrigation Index of Over High-yielding Summer Corn

超高产夏玉米全生育期耗水量为９７５０ｍｍ／ｈｍ２左右，供水量为１０５００ｍｍ／ｈｍ２左右，供水量与耗水量比值１．１左右。开花前耗水量约占４０％～４６％，开花后耗水量约占５４％～６０％。耗水强度苗期阶段最低为４３．０ｍｍ／ｈｍ２·ｄ左右；开花期前后最高，为１３０～１７０ｍｍ／ｈｍ２·ｄ；全生育期平均９６ｍｍ／ｈｍ２·ｄ左右。生育期间的耗水深度呈浅—深—浅梯度变化，大口期前主要耗水层为０～４０ｃｍ，大口—蜡熟为０～８０ｃｍ，蜡熟—成熟０～４０ｃｍ。不同生育阶段０～５０ｃｍ土层土壤相对含水量为播种—拔节８０％～７０％，拔节—大口７０％～７５％，大口—开花７５％～８０％，开花—蜡熟８０％～７５％，蜡熟—成熟７５％～７０％。超高产夏玉米水分运筹掌握足墒播种，适墒出苗，苗期水分适度，穗期、花粒期充分供水，主要耗水层水量较足而均恒，贮水层水量充足而稳定。正常年份砂壤土类需灌水８～９次，中壤土类５～６次，灌水时期分布上应重视底墒水，强调大口，开花水，保证乳熟、蜡熟水，加强花粒期阶段的水分管理。

Water consumption during growing season of over high-yielding summer corn is about 9750 mm/hm 2,water supplying is about 10500 mm/hm 2,the specific gravity of water supplying and water consumption is about 1.1. Water consumption before flowering is about 40%～46% of growing season,after flowering is about 54%～60%. Minimum water consumption intensity is seedling period (43.0mm/hm 2·d±);maximum is flowering period (130.0～170.0mm/hm 2·d);average during growing season is about 96mm/hm 2·d). Depth of water consumption during growing season takes on shallow-deep-shallow gradient change. Before gag period principal water consumption layer is 0～40cm,gag period to dongh period is 0～80cm,dough period to mature period is 0～40cm. Different stages of development soil relative water content of 0～50cm soil: seedling period to shooting period to gag period is 70%～75%,gag period to flowering period shooting period is 75%～80%,flowering period to dough period is 80%～75%,dough period to mature period is 75%～70%. Water management of over high-yielding summer corn should guarantee sowing seed when soil moisture content is enough,seedling emerged in good conditions for soil moisture,seecdling period water appropriating ear period and pollen spore period water supplying fully. Water content of principal water consumption layer is enough and uniform distribution,water storage layer is enough and stable. Normal yield sandy loam soil need irrigate 8～9 times,neutral soil need irrigate 5～6 times. Distribution of irrigation period should emphasize bottom soil moisture water,accent gag and flowering water,guarantee filling and dough water,increasing water management of pollen spore stage.