Land use and elevation effects on soil organic carbon, total nitrogen concentrations and spatial distribution in Rawal watershed of Islamabad (P-0824) (MFN 6333)

Abstract

The spatial variability of soil carbon and total nitrogen levels is important in both global carbon-nitrogen cycle and climate change research. There has been little research on the spatial distribution of soil carbon and soil total nitrogen at the small watershed scale. This study investigated the effects of land use types and elevation on soil carbon and total nitrogen. A total of 13 sites were selected for soil sampling at 3 profile depths (0-15, 15-30 and 30-45 cm). Soil pH, electrical conductivity, bulk density, aggregate stability, soil particle size distribution, inorganic and organic carbon and nitrogen were measured in laboratory of Soil Physics Research Programme, National Agriculture Research Council (NARC), Islamabad and Environment Lab, Bahria University, Islamabad. Both soil carbon and total nitrogen were responsive to land use change. The bulk density of agricultural land was lower than in forest land. Results indicated that aggregate stability of soil particles in forest land was greater than in agricultural land. Soil organic and inorganic carbon was greater in forest as compared to the agricultural land. Data indicated that soil total nitrogen was higher in forest land than in agricultural land. Total carbon in forest land was also higher than in agricultural land. Height shows significant positive correlation with soil inorganic carbon and organic carbon while it shows significant negative correlation with soil total nitrogen.