Abstract
Changes in land use can significantly affect soil properties. This study was conducted in the Taleghan watershed of Tehran Province, Iran, to determine the effects of land use changes on soil organic matter (SOM) and soil physical properties including soil aggregate stability, saturated hydraulic conductivity, infiltration rate, available water content, total porosity and bulk density (BD). In the present study, two sites contained adjacent land uses of natural pasture and dryland farming were selected. Soil samples were taken from depths of 0β15 and 15β30βcm for each land use. The results indicated that the conversion of natural pasture to dryland farming led to a significant decrease in SOM at 0β30βcm in the first and second sites (24.7 and 44.2%, respectively). In addition, a significant increase in BD was observed at a depth of 0β30βcm in dryland farm soils (1.39βgβcm^β3^) compared to pastureland (1.20βgβcm^β3^) at the first site. An increase in BD was also observed at the same depth of dryland farm soils (1.46βgβcm^β3^) and pastureland soils (1.42βgβcm^β3^) at the second site. In addition, total porosity, meanβweight diameter of aggregates, saturated hydraulic conductivity, available water content and estimated final infiltration rate showed significant differences between land uses. The results showed that the conversion of natural pasture to dryland farming alters soil properties that negatively affect soil productivity and erodibility. Copyright Β© 2010 John Wiley & Sons, Ltd.