Properties of Soils under Different Land Uses in Chittagong Region, Bangladesh

In this study, we investigated the effects of three land uses on soil properties in two soil layers; surface soil (0~15 cm) and subsoil (15~30 cm). Soil samples were collected from planted forest, barren lands and cultivated lands from different areas in Chittagong Cox's Bazar and analyzed for some physical and chemical properties. Results showed that soil textural class varied from sandy clay loam in planted forest and barren land site to sandy loam in cultivated soils. Maximum water holding capacity was higher in forest followed by barren land and the lowest in cultivated lands. At both soil depths, soils of cultivated land showed the highest values of bulk density (1.42 to $1.50g\;cm^{-3}$), followed by barren lands (1.37 to $1.46g\;cm^{-3}$) and the least (1.32 to $1.45g\;cm^{-3}$) in forest soils. Total porosity decreased with depth ranging from 40.24% to 41.53% in subsoils and from 42.04 to 43.23% in surface soil of cultivated and of planted forest sites respectively. The result further revealed that organic carbon (OC) and total nitrogen (TN) contents were higher in the planted forest soil than in other two land uses. The soils of all land uses under study are acidic in nature and the lowest pH was found in both surface and subsoils of barren land. Cultivated soil contained the highest amount of available P, Ca, Mg and K in both surface soil and subsoils. In contrast, barren site had the lowest contents of available P, Ca, Mg and K in both layers. The soil organic carbon (SOC) and total N storage were higher in planted forest than in barren and cultivated land uses.