9. Carbon Sequestration in Soils of Different Land Use System in Sirsi Taluka of Uttara Kannada District Through Geo-Informatics Approach

The study was conducted in Sirsi taluka (14°28′0″ N to 14°51′30″ N Latitude and 74°34′0″ E to 75°03′30″ E Longitude) of Uttar Kannada district of Karnataka in India to assess the influence of forests on soil organic carbon. IRS P6 LISS-III imageries for the study area was procured from NRSC, Hyderabad and different land use systems in Sirsi taluka were identified with the ground truth data processed in ERDAS software. The land use classes viz., dense forest, sparse forest, plantation, Agriculture and open land were identified. The total area in each class was assessed through supervise classification. The soil samples at one meter depth were drawn at grid point in flat land and along the profile in sloppy land in different land use system. The SOC was estimated using Walkley and Black rapid titration method. The pattern of Organic carbon distribution in Sirsi taluka is determined using Inverse Distance Weight (IDW) technique in Arc GIS software. The total area in five land use classes is 1,29,964 ha with SOC of 32.38 million tonnes. Among different classes dense forest covers highest area (63,763 ha) and highest SOC pool (21.38 million tonnes). Among the different land use classes, higher SOC was sequestered in horticulture plantations (361.05 t/ha) followed by Dense forest (335.25 t/ha). The SOC in sparse forest and barren land is 239.39 t/ha and 168.74 t/ha respectively. The lowest SOC was recorded in Agriculture land (76.50 t/ha). The CO₂ mitigation potential of horticulture plantation is 4.72 times higher followed by dense forest (4.38 times), sparse forest (3.13 times) and open land (2.21 times) as compared to agriculture land. The study indicated that horticulture plantation and dense forest are the sinks of carbon.