供水压力对微孔陶瓷渗灌土壤水分运移的影响

为探明供水压力对微孔陶瓷灌水器灌水条件下土壤水分运移规律的影响,通过室内土箱模拟试验,研究了3个压力水平下的微孔陶瓷灌水器灌水时的土壤水分入渗特征。研究结果表明,微孔陶瓷灌过程中,供水压力是决定土壤水分初始入渗速率和累计入渗量的关键因素,且供水压力越大,土壤水分初期入渗速率越大,最终累计入渗量也越大;微孔陶瓷渗灌形成的湿润体轮廓为上下不对称的椭球体,湿润锋在各方向上的运移距离与时间呈幂函数关系,其中入渗向上距离水平距离向下距离,供水压力越大,水平最大入渗半径距离灌水器底部距离越远;供水压力对土壤含水分分布影响较大,供水压力越大,灌水器周围含水率越高,高含水率区域越大。在各供水压力水平下,微孔陶瓷渗灌形成的湿润体大小和含水率均能满足作物根系吸水需求。

Effects of Water Supply Pressure on Soil Water Movement Under Ceramic Emitter Irrigation

In order to explore the effects of water supply pressure on soil water movement under porous ceramic emitter irrigation,in-filtration characteristics of soil water were studied under three different water supply pressure degrees through indoor simulation ex-periments.The results indicated that:water supply pressure was the key factor that determined the initial infiltration rate and accu-mulative infiltration amount of soil water,both of them became greater when water supply pressure was getting higher;The shape of soil wetting body was similar to irregular ellipsoid;The wetting front distance showed power function relationship with time in all di-rections,and the infiltration distances of upward,horizontal and downward were in ascending order;Meanwhile,when the water supply pressure was higher,the maximum horizontal wetting distance was farther from the bottom of porous ceramic emitter;Water supply pressure had great impact on soil water distribution,showing the higher water supply pressure,the higher soil water content around the emitter,also larger areas with high moisture content.Wetting body size and moisture content could meet the needs of wa-ter uptake by plant roots under three different water supply pressures with porous ceramic irrigation.