In order to determine the effects of land use on bacterial community composition and some physicochemical properties of soil, a study was carried out in three different land uses (orchard, farm and shrub) in arid-region soils located in southeast of Iran. The selected land uses were adjacent to each other and have not been changed in 50 recent years. Three samples of surface soil were collected from each land use and the bacterial community composition of soil was assessed using denaturing gradient gel electrophoresis (DGGE). Moreover, some soil physicochemical properties were investigated. The results showed that significant differences exist among all of the soil physicochemical properties in different land uses. Higher values of organic carbon, N, P, K, EC, clay, silt, CaCO 3 , Fe, Mn, Zn and Cu and lower values of pH and sand occurred in the agricultural lands (orchard and farm) than shrub land. The results of principal component analysis showed that land use can affect soil properties. Furthermore, results of canonical correspondence analysis showed that the variability in bacterial community composition was related to the selected soil characteristics. Clay and CaCO 3 , sand, and OC, total N and EC were shown to be the most significant properties affecting the bacterial community composition in farm, shrub and orchard land uses, respectively. Generally, the findings of the present study showed that agricultural activities not only did not cause a reduction in species richness, but also resulted in a significant increase in the mentioned indices in orchard and farm land uses compared to shrub land use

Keywords