套管长度和灌水器流量对涌泉根灌入渗特性的影响

Effects of casing length and emitter flow rate on infiltration characteristics of spring root irrigation

为确定黄土高原苹果涌泉根灌时的适宜应用参数(流量和套管长度),选用PP棉滤芯作为配套套管进行室内土箱试验,探究灌水器流量和套管长度对其入渗特性的影响.试验结果表明:大灌水器流量有利于土壤水分在垂直方向上的运移;流量越大,灌水结束时和土壤水分再分布后,湿润体的体积、湿润体内高含水区域范围以及含水率的最大值也随之增大.套管内积水可增大入渗面和入渗水势梯度,从而使土壤水分的运移速率明显增大.灌水器流量和套管长度的交互作用会直接影响土壤水分在水平和垂直方向上的运移,当灌水器流量为12 L/h、套管长度为40 cm时所形成湿润体的体积最大,湿润体内水分分布更均匀,最有利于土壤水分在水平和垂直方向上运移.

In order to determine the suitable application parameters(flow rate and casing length) for root irrigation of apple springs in the Loess Plateau, PP cotton filter element was selected as the supporting casing for indoor soil box tests to explore the influence of the emitter flow rate and the casing length. The test results show that a large emitter flow rate is conducive to the migration of soil moisture in the vertical direction. The larger the flow rate, the greater the volume of the wet body, the range of high-water content areas in the wet body, and the maximum water content at the end of irrigation also increases accordingly after the redistribution of soil water. The accumulated water in the casing can increase the infiltration surface and the infiltration water potential gradient, thereby significantly increa-sing the migration rate of soil moisture. The interaction between the emitter flow rate and the casing length will directly affect the horizontal and vertical migration of soil moisture. When the emitter flow rate is 12 L/h and the casing length is 40 cm, the volume of wet body formed is the largest, and the water distribution in wet body is more uniform, which is the most conducive to the horizontal and vertical movement of soil moisture in the horizontal and vertical directions. This study will provide technical reference for the spring root irrigation technology in Loess Plateau.