[关键词]
[摘要]
通过防雨棚下测坑试验,研究不同生育期干旱,设轻度干旱和重度干旱对夏玉米生长状况、耗水规律、产量以及水分利用效率的影响。结果表明,不同生育期干旱均会抑制植株株高和叶面积指数增长,受旱越重,株高和叶面积指数越小。适宜水分处理的植株株高与叶面积长势优于其他处理;与适宜水分处理相比,随着干旱时期的后移,产量呈先降后升的趋势,其中,苗期轻度干旱的处理减产最少,为9.88%,抽雄期重度干旱穗粒数最少,为349.98粒,减产最多,达32.67%;夏玉米拔节期重度干旱处理的耗水量最低,为258.09 mm,任何生育阶段受旱,其日耗水量随着干旱程度的加重而降低。对各处理产量和耗水量进行分析,两者呈良好的二次曲线关系,拔节期轻度干旱处理的水分利用效率(WUE)最高,为2.202 kg/m3,其次是苗期重度干旱的处理,后期干旱处理由于减产幅度超过节水的幅度,WUE降低。通过对各处理的产量和WUE综合分析,确定了夏玉米节水高产的灌溉控制指标。
[Key word]
[Abstract]
By the experiment for test-pits under a rain shelter, the effects of drought at different growth stages and different water availabilities on growth, water consumption, yield and water use efficiency(WUE) of summer maize were studied. The results showed that drought at different growth stages would inhibit the increase of plant height and leaf area index(LAI). The more severe the drought hit, the smaller the plant height and LAI. Suitable for water treatment, the plant height and LAI were growing better than the other treatments. The yield showed the first rise after falling trend with drought time occurring later. The output reduction in seedling stage with the light-water deficit treatment was the least, that was 9.88%, while the grain number per spike in tasseling stage with the severe water deficit treatment was the lowest, was 349.98, and then the yield reduction was the greatest, was 32.67%. The water consumption of the severe water deficit at jointing stage treatment was the lowest at 258.09 mm. Any growth stage of drought-hit, its days as the water consumption decreased the severity of drought. Through the yield and water consumption of summer maize analysis, both showed a good relationship between the quadratic curves. WUE of the light-water deficit at jointing stage was the highest, 2.202 kg/m3, followed by treatment of dry weight in seedling stage. And because of the magnitude of production decrease was more than water-saving in late stage, WUE decreased. Finally, according to the results of yield and WUE in different treatments, properly reduce the limit of soil moisture for water-saving and high-yield in summer maize was put forward in this paper.
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[基金项目]
国家现代玉米产业技术体系建设专项资金(nycytx-02-18)、国家科技基础性工作专项“中国农业气候资源数字化图集编制”(2007FY120100)