Effect of Daily Irrigation on Water Content and Suetion Profiles in Soils of Three Textures

Abstract

AbstractA growth‐room study was conducted to evaluate the water and suction profiles that develop in various soils irrigated daily at different proportions of Et. When irrigated to just replace Et, the water profiles that developed depended upon the flow characteristics of the soil. In the soil in which water moved readily (Shano silt loam), water distribution was nearly uniform with depth and did not change with time. In the soils in which water moved slowly, either because of slow internal water movement when wet (Ritzville loam) or low unsaturated conductivities at relatively low suctions (Sagehill sand), the upper soil became wetter while the lower soil water decreased by a corresponding amount. In all soils irrigated daily to replace all or more than Et, suctions in the upper soil were relatively low. With the soil profile initially wet, several weeks of deficit irrigation passed before surface soil water content changed markedly.