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夏玉米经济产量与耗水量呈二次函数关系．玉米苗期阶段吸水范围主要在0～20cm土层，中、后期吸水范围主要在0～40cm土层．大口期以后缺水，穗粒数和千粒重与0～100cm深土层绝对含水量的关系呈二次函数变化．夏玉米耗水量前期少，后期多，9000kg／hm2产量水平，全生育期总耗水量6750mm／hm2左右，平均耗水强度69．5mm／hm2·d，拔节期～大口期67．7mm／hm2·d，大口期～开花期81．2mm／hm2·d，开花期～乳熟期78．5mm／hm2·d。乳熟期～成熟期65．7mm／hm2·d．阶段耗水量动态分布为：苗期阶段990mm／hm2，穗期阶段2175mm／hm2，花粒期阶段3639mm／hm2，生育前半期耗水量占总耗水量的46．5％，后半期占53．5％．模系数分布动态为：苗期阶段14．6％，穗期阶段31．8％，花粒期阶段53．5％。各生育阶段适宜的土壤水分指标为：播种～拔节田间相对持水量70％～60％，拔节～大口70％～75％，大口～开花70％～80％，开花～乳熟80％左右，乳熟～成熟80％～70％．夏玉米灌溉水分生产效率表现为报酬递减规律，底墒水水分生产效率最高，其次为开花水，9000kg／hm2夏玉米的水分生产效率为60kg／mm·hm2．夏玉米灌水最佳经济效益有一个适度．9000kg／hm2左右的适度值为1800～2400mm／hm2左右。正常年份夏玉米全生育期?
Summer corn economic output and water consumption showed a quadratic function. Water absorption range of maize seedling stage mainly in 0 ~ 20cm soil layer, the middle and late absorption range mainly in 0 ~ 40cm soil layer. The relationship between water deficit, grain number per spike and 1000-grain weight and absolute water content of 0-100 cm deep soil layer showed a quadratic function change after the big mouth stage. The water consumption of summer maize was less in the early period, the later was more, the production level was 9000kg / hm2, the total water consumption in the whole growth period was about 6750mm / hm2, the average water consumption intensity was 69.5mm / hm2 · d, the jointing stage-big mouth 67.7mm / hm2 · d, big mouth - flowering 81.2mm / hm2 · d, flowering ~ milk mature 78.5mm / hm2 · d. Milky maturity ~ maturity 65.7mm / hm2 · d. The dynamic distribution of water consumption during the stage was: 990mm / hm2 in seedling stage, 2175mm / hm2 in panicle stage and 3639mm / hm2 in anthesis stage. The water consumption in the first half of growth period accounted for 46.5% of the total water consumption, and the latter half accounted for 53.5 %. The dynamic distribution of modulo coefficient is 14.6% in seedling stage, 31.8% in heading stage and 53.5% in anthesis stage. The suitable soil moisture index in each growth stage is as follows: relative water holding capacity of 70% ~ 60% in sowing to jointing field, 70% ~ 75% of jointing ~ big mouth, 70% ~ 80% Cook ~ mature 80% ~ 70%. The water production efficiency of summer maize irrigation showed the law of decreasing returns, the moisture production efficiency of top soil moisture was the highest, followed by the flowering water, and the water production efficiency of 9000kg / hm2 summer maize was 60kg / mm · hm2. Summer corn irrigation best economic benefits have a modest. The moderate value of 9000 kg / hm2 is about 1800 to 2400 mm / hm2. Normal year summer corn full growth period?