【摘要】 棉花是我国西北内陆干旱地区主要的农作物,研究干旱区棉花的水分利用来源对合理制定灌溉制度、实现农业节水灌溉和保证作物稳产高产具有重要意义.在新疆生产建设兵团炮台土壤改良试验站,基于水文监测和氢氧稳定同位素方法分析膜下滴灌棉田土壤水中氢氧同位素的动态变化特征,确定棉花不同生育期及灌溉后的水分利用来源,并应用多水源混合模型(IsoSource模型)定量计算了棉花对不同深度土壤水的利用率.研究结果表明:棉花在蕾期、花期、铃期和吐絮期主要的水分利用来源及利用率分别为030cm(78.2%)、3060cm(31.9%)、60110cm(32%)、110220cm(47.3%),整个生育期内水分利用来源存在由浅变深的规律.膜下滴灌后,棉花调整其水分利用来源,显著增加了030cm浅层土壤水的利用率.综合试验结果表明低额高频的灌溉制度可以提高棉花对灌溉水的利用率.更多还原

【Abstract】 Cotton is the main crop in arid areas of Northwest China.Study on the water sources of crops is of great significance to make proper irrigation schedules and realize agricultural water-saving irrigation in arid regions.In this study,precipitation,irrigation water,soil water and cotton stem water were sampled for stable isotope analysis in the Paotai Soil Improvement Test Station in Xinjiang Production and Construction Corps.Based on the stable hydrogen and oxygen isotopic tracing method and hydrological observations,the dynamic variation of stable isotope values in soil water under mulched drip irrigation was analyzed to determine the water sources of the cotton in different growth stages and the sources after irrigation pulse.The contributions of soil water at different depths to cotton water uptake were quantified by the IsoSource model.Results show that the main uptake depth of soil water in bud stage,blooming stage,boll stage and open boll stage are distributed in 0 to 30 cm layer(78.2%),30 to 60cm layer(31.9%),60 to 110cm layer(32%)and 110 to 220cm(47.3%),respectively.The main sources of water used by cotton gradually increase with the advance of growth stage.Cotton adjusts rapidly water sources after mulched drip irrigation,by significantly increasing the proportions of water use in 0to 30 cm soil.The results also indicate that the proper irrigation schedule with low irrigation volume and high irrigation frequency can improve the utilization efficiency of irrigation water in arid regions.更多还原