原状土柱模拟不同降水年型条件下冬小麦、夏谷子耗水量研究

Study on Water Consumption of Winter Wheat and Summer Millet Using Undisturbed Soil Columns under Different Precipitation Years

为合理利用旱地水资源和指导旱地农业生产,利用PVC管材采集河南旱作区褐土原状土柱,在简易防雨棚条件下对冬小麦、夏谷子的耗水状况进行测定。结果表明:冬小麦总耗水量中,丰水年型降水占77.2%,平水年型降水占67.1%,缺水年型降水占64.0%。夏谷子总耗水量中,丰水年型占同期自然降水量的97.8%,平水年型占同期自然降水量的92.1%,缺水年型同期自然降水量占总耗水量的83.13%。说明在丰水、平水年型情况下,自然降水基本能满足夏谷子水分需要。从作物阶段耗水测定结果看,丰水年型情况下,冬小麦、夏谷子均存在奢侈耗水现象;平水年型自然降水能基本满足夏谷子水分需求,但突出问题是阶段性、间隙性水分缺乏,这在冬小麦上表现的更为明显;缺水年型情况下,自然降水均不能满足冬小麦、夏谷子的水分需求,其突出问题主要表现在,一是水分状况制约着冬小麦、夏谷子正常播种和出苗,二是水分供应状况影响作物的生长发育进程。

For the rational use of water resources and offering guidance of dryland agricultural production, an experiment in a simple rain-proof shed was conducted to determine water consumption of winter wheat and summer millet in undisturbed soil columns packed in PVC tubes. Results showed that precipitation in rainy years accounted for 77.2% of the total water consumption of winter wheat,67. 1% in normal years,and 64.0% in dry years. For summer millet, total water consumption took up 97.8% of precipitation in rainy years,and 92.1% in normal years ; While in dry years,the precipitation took up 83.13% of the total water consumption. It was suggested precipitation in rainy and normal years could meet the needs of summer millet growth. From the results of water consumption stage of crops＇, luxury water consumption was observed during the growth of winter wheat and summer millet in rainy yeas; Precipitation could basically meet the demand of summer millet growth in normal years, however, interim water deficiency occurred especially for winter wheat; Natural precipitation in dry years could not supply enough water for winter wheat and summer millet, resulting in delayed sowing time, germination and growth process.