No abstract

An assessment on fertility status was carried out on the soils of Nandipura micro-watershed during the year 2018-2019. Forty-eight grid samples were collected and analysed for its fertility status and were mapped using ArcGIS software. The mapping of fertility status of soils of Nandipura micro-watershed revealed that the soils were low (86.52% of the micro-watershed area) to medium (8.57%) in available nitrogen content, low (44.02%) to medium (51.07%) in available phosphorus, low (15.20%) to medium (79.89%) in available potassium, medium (21.56%) to high (73.52%) in available sulphur, exchangeable calcium and magnesium content were sufficient in entire micro-watershed area. DTPA extractable zinc was deficient in 105 ha and sufficient in 370 ha area whereas, DTPA extractable iron, copper and manganese were sufficient throughout the study area. Available boron was low (34.38%) to medium (60.25%).

Assessment of carbon fraction was undertaken in Nandipura mini-watershed area under different land-use systems. Eight land-use systems were selected viz; agricultural system (maize, ragi and groundnut), horticulture system (arecanut, coconut and pomegranate), fallow land and scrubby land for the study of dynamics of carbon. Among the different land-use systems, horticultural land use systems recorded significantly higher potassium dichromate oxidizable carbon (PDOC), potassium permanganate oxidizable carbon (PPOC), Cold water extractable carbon (CWEC), soil microbial biomass carbon (SMBC), Total organic carbon (TOC), Total inorganic carbon (TIC) and Total Carbon (TC) at three depths of soil (0-20 cm, 20-40 cm and 40-60 cm) followed by agricultural land-use system. Significantly higher carbon stock was recoded under arecanut land-use system (30.95 t C ha -1 ) at surface depth and least carbon stock was recorded under maize land-use system (17.29 t C ha -1 ). Similar trend was observed at subsurface layers.