Assessing the physico-chemical and biological properties of soil under different land use types in southern transect of Bengaluru, Karnataka-India

Abstract

Soil is key resources upon which the functioning of all biological land use depends, and the most important component of sustainable agriculture with this view the study was conducted to assess physicochemical and biological properties of soil under different land use types in southern transect of Bengaluru. Fifty soil samples were collected from each land use system viz agriculture, horticulture, mulberry and plantation land use. The soil was examined for various physico-chemical and biological properties including sand, silt, clay, soil pH, organic carbon (OC), electrical conductivity (EC), available nitrogen (N), phosphorus (P) and potassium (K), exchangeable calcium (Ca) and magnesium (Mg), sulphur (S), micronutrients (Zn, Fe, Mn, Cu and B) and heavy metals (Cd, Cr, Ni and Pb) and dehydrogenase activity (DHA). The results of the experiment reveled that soil pH varies from strongly acidic (4.23) to strongly alkaline (8.56), low (0.39 dS m-1) to high (0.88 dS m-1 ) EC content. Whereas OC content under different land use systems was in the medium range. The significantly higher soil OC, available N, P2O5 and K2O recorded in agriculture land use. The exchangeable Ca (10.71 c mol (p+) kg-1) and Mg (7.96 c mol (p+) kg-1) recorded significantly higher in agriculture land use. Plantation land use marked significantly higher Fe (12.99 ppm) and Mn (8.51 ppm) contents followed by mulberry (12.16 ppm and 8.23 ppm), Whereas Zn and B were found high in agriculture land use system (0.80 ppm and 0.85 ppm) compare to other land use systems. Heavy metals (Cr, Pb and Ni) were found nonsignificant. Whereas Cd was found significantly different among the land-use system and found high in horticulture land use system (0.049 ppm). Conclusively, land use change affects soil physico-chemical and biological properties.