EFFECTS OF DIFFERENT LAND USES ON INFILTRATION IN UNSTIFLUVENT SOIL SUSCEPTIBLE TO GULLY EROSION

The effects of different land uses, viz agriculture, grassland and aff orestation, were evaluated in comparison with untreated ravine waste l and in ustifluvent soil susceptible to gully erosion under a semiarid climate. The infiltration was measured with constant head double ring infiltrometers. Saturated hydraulic conductivities for the study sites were computed with a clay based equation and a texture based equation . The difference between the final infiltration rate (after 180 min) a nd the saturated hydraulic conductivity was taken to be the effect of different land uses on the infiltration characteristics of the sites. The saturated hydraulic conductivities (K-s) calculated by the two met hods were comparable for loamy sand soil. The two K-s values were diff erent for sandy loam soil. The ravine proper and farming up and down c ultivation practice under grazing and trampling etc. were found to hav e suppressed the infiltration rate. Agricultural land use on terraces showed a marginal increase. Thus, the study demonstrated a way of isol ating the effect of different land uses using a simple method for the estimation of saturated hydraulic conductivity for ustifluvent soils. For structure-dominated soils a more precise determination of saturate d hydraulic conductivity will be necessary.