夏玉米需水及耗水规律的研究

分析了试验地区夏玉米在降雨年型为-干旱年的需水与耗水规律。结果表明，试验条件下，夏玉米全生育期需水量为359．8mm。夏玉米日需水强度呈抛物线型，苗期较小，拔节到抽雄达到最大，抽雄到酸浆后需水强度逐渐减小。土体供水在耗水来源组成中所占比例很小，甚至出现负供水。但是在某个生长发育阶段，特别是出现水分胁迫的条件下，土体供水可在玉米耗水组成中占主导地位。

Study of Water Demand and Consumption Rules in Summer Maize

In this study, rules of water demands and consumption by summer maize were analy zed. There is a total water demand of 359.8 mm during the whole growth stage of maize.Daily water demand in the whole growth period appeared to be a parabola: l ow in seedling stage, increased until reach its peak while from node elongation to tasseling and decreased gradually after tasseling and grain filling. Rainfall and irrigation provides most of water consumed by summer maize,while so il water supply contributes little, in some cases, there is even minus supply. B ut when some certain growth stage was inspected, especially when there is a wate r stress, soil water supply may be the main source and contributed much.