Study on the Effect of Initial Soil-Water Content and Bulk Density on Horizontal Infiltration in a Sandy Loam Soil

The effect of initial soil-water content (0.02 and 0.08 cm3 cm−3) and bulk density (1.5 and 1.6 g cm−3) on infiltration of water in an alluvial sandy loam soil were studied and predicted on the basis of unsaturated flow theory of Philip. At any particular time, with the increase in bulk density or initial moisture content the sorptivity decreased with a concomittant decrease in infiltration rate. During a particular period the depth of wet-fronts and velocity of wet-front advancement were greater in soil having higher initial water content and lower bulk density. The predicted moisture profile, sorptivity, cumulative influx, infiltration rate, depth of wet-front and rate of advancement of wet-front were in good agreement with the corresponding experimentally observed values. The reciprocity constants relating cumulative influx and infiltration rate or velocity of wet-front advancement and the proportionality constants relating cumulative influx and wetting-depth were found out. Such constants are useful in predicting moisture movement in soil at any amount of water influx.