摘要： 利用防雨设施研究了不同土壤目标含水量对夏玉米光合性能及产量的影响。结果表明，土壤水分含量与产量密切相关，夏玉米产量形成的土壤水分临界值为田间持水量的45%左右，最佳产量形成的土壤水分临界值为80%，50%左右是夏玉米出苗的土壤水分临界值，70%左右是最佳出苗率的土壤水分临界值。土壤干旱及过湿均使光合面积、光合势、干物质积累强度及光合速率下降，导致大幅度减产。夏玉米不同生育阶段对水分的需求量有别，有益于夏玉米光合性能的土壤水分指标为：苗期阶段50%~80%，拔节后为60%~80%，以70%~80%为最优。

关键词: 夏玉米, 土壤目标含水量, 光合性能, 产量

Abstract: The effect of different target water content in soil on the photosynthetic property and yield of summer-sowing corn was studied under the rain-proof condition. The results showed that the moisture content in soil was closely related to yield, the critical values of moisture content in soil were 45% of field water capacity at period of yield formation, 80%at period of optimum yield formation, 50% at period of seedling emergence, 70% at period of optimum seedling emergence. Dry or over-wet soil tended to decrease photosynthetic area, potential and rate, the accumulative intension of dry matter, that caused the drop of crop yield with a great scope. The requirement for soil water content differed at the different growing time, the water indices that were useful for the summer-sowing cron photosynthetic property were: 50% to 80% for the seedling stage, 60% to 80% for the jointing stage and after that, and 70% to 80% was the best excellent.

Key words: Summer-sowing corn, Target water content of soil, Photosynthetic property, Yield