耕层土壤含水量消长规律的分析

利用濉溪县耕层土壤含水量和同期观测的降水量、蒸发量资料,研究表明:耕层土壤含水量的消长与基期土壤含水量、期间降水量和蒸发量呈多元直线相关关系,其中耕层土壤含水量增加量主要取决于基期土壤含水量和降水量;土壤含水量减少量主要取决于蒸发量和基期土壤含水量。耕层土壤相对含水量在50%~65%,需降水或补充灌溉22.9~49.3 mm的水量。降水效力与基期土壤含水量、降水量呈多元指数曲线关系,蒸发效力与基期土壤含水量呈指数曲线关系。耕层土壤含水量的消退呈"快—缓慢—滞缓"的变化过程。使耕层相对含水量达到80%以上的一次降水(过程)过后,连续11.2~47.1 d无降水,耕层相对含水量尚可维持在60%以上。

Analysis of Growth and Decline taw of Soil Water Content in Tilth Layer

The research conducted by using the data of soil water content in tilth layer in Suixi County and the observed precipitation and evaporation in the same period showed that the growth and decline of soil water content in tilth layer had multi-linear correlation with the soil water content,precipitation and evaporation in the base period,in which the increment of soil water content in tilth layer was mainly decided by the soil water content in tilth layer and precipitation in the base period,the decrement of soil water content was mainly decided by the evaporation and soil water content in the base period.The relative soil water content in tilth layer was at 50%～65% and 22.9～49.3 mm water amount of precipitation or supplementary irrigation was needed.The precipitation efficacity showed multi-index curve relationship with the soil water content and precipitation in the base period and the evaporation efficacity showed index curve relationship with the soil water content in the base period.The decline of soil water content in tilth layer showed the change course of "fast-slow-creeping".The relative water content in tilth layer could still be kept over 60% in the continuous 11.2～47.1 d without precipitation after a precipitation(course) made the relative water content in tilth layer got over 80%.