Soil Organic Carbon Pools under Terminalia chebula Retz. based Agroforestry Systemin Himalayan Foothills, Indiax

Knowledge of carbon (C) pools in soils is helpful in devising practices for efficient carbon management in intensive cropping systems. Carbon fractions of soil organic carbon are used asan indicator for land-use induced change in soil quality. The present study evaluated carbon pools under Terminalia chebula(chebulic myrobalan) based agroforestry system supplied with different nutrient sources, viz. farmyard manure, poultry manure, vermicompost, wheat straw and inorganic fertilizer (NPK @ 100:80:60). Carbon fractions, viz. very labile (C₁ frac), labile (C₂ frac), less labile (C₃ frac) and non-labile (C₄ frac), were analysed at 0–15 and 15–30 cm soil depth. The higher value of C₁ frac (13.8%), C₂ frac (4.8%), C₃ frac (8.3%) and C₄ frac(11.1%) were recorded under agroforestry as compared to open system. Among the nutrient sources, all the carbon fractions were higher under 100% integrated nutrient sources as compared to controlled treatment. Microbial biomass carbon (MBC) was recorded higher (298.31 μg g^–1 ) under agroforestry system compared to the open system (290.63 μg g^–1 ) at 0–15 cm. Among the different nutrient sources, higher MBC (458.66 μg g^–1 ) at 0–15 cm and lower (340.59 μg g^–1 ) at 15–30 cm soil depth was recorded in 100% integrated treatment.Thus, agroforestry-based land-use types and integrated nutrient management are more efficient for soil health and carbon management in Himalayan foothills.