Land resource inventory and its applications for watershed planning: A case study of Harawala sub-watershed of Semi-Arid region of Jewargi taluk, Kalaburagi district, Karnataka, India

Abstract

A case study was, undertaken to evaluate land resources of Harawala Sub-watershed located in North Eastern Dry Zone of Karnataka (Zone-2) in semi-arid, region of Jewargi Taluk, Kalaburagi District under REWARD project, sponsored by the Watershed Development Department of Karnataka and funded by the World Bank. A total 15 soil series were identified in that majorly 5 soil series (KCP, MGT, CMB, RNP, GTT) covered a more area (75%) which shows in Table 1. In all the pedons, dominant soil texture was clay. The fertility status of soils revealed that majority of soils were moderately alkaline (pH 7.8-8.4) in reaction, low to medium in organic carbon content (<0.5-0.75> %), low to medium in nitrogen (N) content (<280-560> kg ha-1), medium in phosphorus (P2O5) content (<22.5-56> kg ha-1), high in potassium (K2O) content (>336 kg ha-1) and low to medium in available sulphur (S) content (10-20> ppm). The analysed surface soil samples revealed that the DTPA extractable micronutrients viz, Fe (>4.50 ppm), Mn (>3.00 ppm) and Cu (>0.50 ppm) were sufficient, while Zn (<0.60 ppm) were deficient. In land capability classification, a total 5 sub classes were identified in that majorly 2 classes (III & IV) covered a more area (86%), which includes erosion and soil (depth, gravelliness, texture, salinity/alkalinity) limitation. Under crop suitability most of the series were currently not suitable (Nr) for Sunflower, Mango, Sapota, Tamarind, marginally (S3) suitable for Bajra, Sorghum, Pigeon pea, Groundnut, Cotton and moderately (S2) suitable for Bengal gram crops. By interfacing land resource, data with Remote Sensing, GIS techniques, different management scenarios, were analyzed to arrive at the best management alternatives (optimum land use plans), that would be most suitable.