Vol. 8, Special Issue 12, Part R (2024)

This research endeavours to evaluate the fertility status of the Sunnadhahalli micro-watershed, situated within the Upper Tungabhadra catchment area, a critical region for agricultural productivity and environmental sustainability. Through systematic soil sampling at 0-20 cm depths and utilizing prescribed standard methods, soil attributes were meticulously determined. Employing advanced geospatial techniques, including ArcGIS software and kriging interpolation, comprehensive soil nutrient status and fertility maps were generated. The findings revealed a spectrum of soil reactions ranging from strongly acidic to moderately alkaline (4.83 to 8.45), indicative of diverse soil conditions and soils are non-saline. Notably, the soil organic carbon content exhibited variations from low to high levels (2.10 to 11.40 g kg^-1), influencing soil health and productivity. Similarly, available nitrogen levels ranged from low to medium (85.30 to 425.87 kg ha^-1), posing challenges for optimal crop growth. Crucially, the study highlighted varying levels of available phosphorus (16.60 to 83.36 kg ha^-1), potassium (152.01 - 527.39 kg ha^-1) and sulphur (13.95 to 60.88 mg kg^-1), essential for plant nutrient uptake and growth. Exchangeable calcium (5.60 to 44.25 cmol (p⁺) kg^-1) and magnesium (1.80 to 9.90 mol (p⁺) kg^-1) were found to be sufficient. Micronutrient analysis uncovered fluctuations in boron levels (0.32 to 0.93 mg kg^-1), while available iron, zinc, copper and manganese exhibited sufficient levels across the study area. These insights underscore the significance of assessing soil nutrient status for informed land management decisions, facilitating sustainable agricultural practices, optimizing crop yields, and safeguarding environmental health in micro watershed ecosystems.