EFFECT OF SEASONS AND LAND USE ON SOIL NUTRIENTS IN THE SEMI-ARID RIDGE FOREST ECOSYSTEM OF DELHIEkta and Ratul BaishyaAbstract Season and land use have a significant impact on soil nitrogen dynamics. Studies on the effect of seasons and land use on soil nutrients is limited in semi-arid forests. The study was conducted in the Delhi Ridge Forestâs Northern Ridge (NR) and South-Central Ridge (SCR). The natural and managed sites were sampled at 0-10 and 10-20 cm depths to study the soil physico-chemical properties in different seasons. The natural and managed sites of the ridge had similar soil moisture (SM), nitrogen (N), phosphorus (P), and sodium (Na) concentrations. Soil pH increased with depth (p < 0.05) and positively correlated with calcium (Ca), magnesium (Mg), and sodium (Na) contents (r = 0.67**, 0.62**, and 0.59*, respectively). The total carbon (TC), soil organic carbon (SOC), and N correlated negatively (p < 0.05). Soil organic carbon (SOC), total carbon (TC), soil organic matter (SOM), N, P, and potassium (K) were higher (p < 0.01) in the topsoil (0-10 cm) than in the subsoil (10-20 cm depth) and peak in pre-monsoon and least in winter. The SCR had the maximum K, Ca, and Mg concentrations, whereas NR had the highest SOC, TC, SOM, N, P, S, and Na concentrations. Na, Ca and Mg were highest in winter season. Topsoil accumulation of TC, SOC, N, P, K,and Na suggests that nutrient cycling is faster than leaching and may have a stronger chemical attraction to organic matter. |