Soil organic carbon density under different agroforestry systems along an elevation gradient in north-western Himalaya

The present study was carried out to understand the variation in soil organic carbon (SOC) density under different agroforestry systems (agri-silviculture, agrihorticulture, agri-horti-silviculture, agri-silvi-horticulture, silvipasture and grasslands) prevailing at three elevations of E₁ (900-1300m; mixed deciduous forest), E₂ (1301–1700 m; chirpine forest) and E₃ (1701–2100 m; oak forest) in Giri catchment of Himachal Pradesh, Himalaya. The results revealed that significantly higher mean SOC was observed in agri-horticulture system (2.22%) as compared to other systems. The bulk density of soil was significantly higher at elevation E₃ (1.28 g cm⁻³) as compared to other elevation ranges. Mean maximum soil organic carbon density upto 30 cm soil depth was observed in grassland (53.45 t C ha⁻¹) followed by agrihorti-silviculture (52.57 t C ha⁻¹), agri-horticulture (51.88 t C ha⁻¹), agri-silvi-horticulture (51.18 t C ha⁻¹) and agrisilviculture (50.01 t C ha⁻¹). Higher SOC density (53.91 t C ha-¹) was recorded at elevation E₃.