Soil carbon stocks in natural and man-made agri-hortisilvipastural land use systems in dry zones of Southern India

A study was undertaken to assess the soil carbon stocks in 0–50 cm soil depth, under natural and man-made land use systems in the eastern dry zones of Karnataka in India. The carbon (C) stocks in soils ranged from 26.46 t ha⁻¹ in dry land agricultural systems (without manure) to 89.20 t ha⁻¹ in a mixed forest. Among natural systems, mixed forest (89.20 t ha⁻¹) and ungrazed grassland (71.78 t ha⁻¹) recorded higher levels of C stock than other systems, while grazing in grassland and litter removal in teak plantations correlated to reduced carbon stocks to 39.32 and 32.74 t ha⁻¹, respectively. Intensively managed horticultural systems namely, grapes plantation (85.52 t ha⁻¹) and pomegranate plantation (78.78 t ha⁻¹) maintained higher levels of C stock. However, agricultural systems recorded moderate to lower levels. Total carbon stocks in top 0–50 cm soils of agricultural systems was in the order: irrigated lands with manure application (52.77 t ha⁻¹) > irrigated lands without manure application (44.47 t ha⁻¹) > dry lands with manure application (37.79 t ha⁻¹) > dry lands without manure application (26.46 t ha⁻¹). It was observed that adoption of appropriate soil and crop management practices such as conservation tillage, good irrigation, incorporation of crop residues and application of manure etc. could enhance soil C pool by reducing existing carbon loss and promoting C accumulation in the soil.