Edward Saleh1, Budi I. Setiawan2(1. Sriwijaya University, Indonesia; 2. Bogor Agricultural University, Indonesia)Abstract: Pitcher, a bottle-like irrigation emitter made of baked clayed soils mixed with sands has been recognized as the oldest traditional irrigation. It has high water efficiency since the water seeps directly into and concentrated in the root zones. Numerical and experimental studies were conducted to investigate the water flow in the soil surrounding a pitcher and to figure out the availability of soil moisture for crops. The Darcy and Richards’ equations of water flow in a cylindrical coordinate system was applied and was solved using Finite Element Method to describe soil moisture profiles. Two soil textures were used, one was silty clay and the other was sand. The hydraulic conductivity of the pitcher was in order 10-6 cm/s which was 100 times smaller than that of the two soils. The pitcher was buried in the center axis of a soil box and water was given from Mariotte tube to maintain a constant water level inside the pitcher. The results showed the infiltration rates decreased linearly rather than exponentially even though the soil was initially dry. The advancement of wetting front was very slow and somewhat limited to a radius and depth of no more than 30 cm and 40 cm, respectively for both tested soils. The surrounding soil moisture was in a range available for plant growth. Different depths of pitcher placement in the soil produced different reaching distances of the wetting front but showed insignificant differences in water availability. Accurate placement of pitcher depth in soil is important to provide effective soil wetness in the root zone and reduce evaporation rate. The right placement of pitcher must be determined based on the hydraulic characteristics of the pitcher and the soil. In this study, 5 cm placement depth of the pitcher’s shoulder is an appropriate reference for the application of pitcher irrigation.
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机译：Edward Saleh1，Budi I. Setiawan2（1。印尼斯里维贾亚大学; 2。印度尼西亚茂物大学）摘要：Pitcher是一种瓶形灌溉喷头，由烘烤的黏土和沙子混合而成，已被认为是最古老的传统灌溉方式。由于水直接渗入根区并在根区集中，因此具有很高的用水效率。进行了数值和实验研究，以研究投手周围土壤中的水流，并计算出作物土壤水分的利用率。应用了达西和理查兹在圆柱坐标系中的水流方程，并使用有限元法对其进行了求解，以描述土壤水分剖面。使用了两种土壤质地，一种是粉质粘土，另一种是沙子。投手的水力传导率约为10-6 cm / s，比两种土壤的水力传导率小100倍。将水罐埋在土壤箱的中心轴上，并从马里奥特管中注水，以保持水罐内恒定的水位。结果表明，即使土壤最初是干燥的，入渗率也呈线性而非指数级下降。两种试验土壤的润湿锋面进展非常缓慢，并且其半径和深度分别限制在不超过30 cm和40 cm。周围的土壤湿度在可用于植物生长的范围内。投手在土壤中放置的深度不同会导致湿润前沿的到达距离不同，但水分利用效率差异不明显。在土壤中准确放置水罐深度对于在根部区域提供有效的土壤湿度并降低蒸发速率非常重要。必须根据投手和土壤的水力特性确定投手的正确位置。在这项研究中，水罐肩部5厘米的放置深度是水罐灌溉应用的适当参考。
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