Soil Fertility Mapping Using GIS in Sirur Sub-Watershed of Kundagol Taluk of Dharwad District, Karnataka, India

Aims: To identify available nutrient constraints in soils and to generate soil fertility maps using remote sensing and GIS of Sirur sub-watershed in northern dry zone of Karnataka.

Place and Duration of Study: The study was carried out in the Sirur sub-watershed (4D5B5j) located in Kundagol taluk of Dharwad district, Karnataka during 2022-24.

Methodology: Soil samples (601) from Sirur sub-watershed in northern dry zone of Karnataka were drawn at 320 m x 320 m grid interval and assessed for fertility parameters. Analytical data was interpreted and statistical parameters like range, mean, standard deviation and coefficient of variation were calculated for each parameter. Soil fertility maps were prepared for each parameter using interpolation technique.

Results: Soils were neutral to alkaline in reaction and non-saline. Soil organic carbon content was low to medium. Available nitrogen and phosphorus were low to medium, available potassium was high and sulphur was medium to high. Regarding available micronutrients, iron, copper and manganese were sufficient in the soils whereas Zn was deficient in about half of the sub-watershed area and B content was medium to high.

Conclusion: The major constraints in sub-watershed are low content of OC, poor status of available N, P2O5 and Zn indicating their immediate attention for sustained crop production.