干旱区生态环境知识资源中心

Small water resources can be utilized more effectively in the drip irrigation system. To use limited water effectively, it is important to irrigate exactly in the root zone. First, hydraulic conductivities and diffusivities on various soil types were studied. The experiment was performed on sand (Coastal sand), sandy loam (Masa), loam (Kuroboku, volcanic ash) and clay (Coral clay). Second, cylindrical compartment model to estimate wet bulb size was proposed. Wet bulb formations on various soils were studied with changing the irrigation intensity. Sand soil typically showed vertical elongation arid light clay soil showed horizontal elongation. Loam (Kuroboku) and sandy loam (Masa) showed spherical elongations. Sandy loam (Masa) showed slightly vertical elongated shapes than Loam (Kuroboku). Third, the sizes of wetted area on the soil surface and of vertical depth were determine on specified irrigation intensities.