Identification of soil fertility constraints by GIS in Kadadi sub-watershed under northern dry zone ofKarnataka for site specific recommendations

Abstract

Soil samples from Kadadi sub-watershed in northern dry zone of Karnataka were drawn at 320 m grid intervalsand assessed their fertility. Analytical data was interpreted and statistical parameters like range, mean standard deviation,coefficient of variation, kurtosis and skewness were calculated for each parameter. Soil fertility maps were prepared foreach nutrient using Arc GIS v 10.4. Soils were moderately alkaline to strongly alkaline with non saline to slight salinity.Majority of area in micro-watershed had low to medium in soil organic carbon, nitrogen was low, available phosphorouswas low to medium, available potassium was high, available boron and sulphur was low to medium. Regarding availablemicronutrients, zinc and iron were deficient in more than half of the sub watershed area, whereas copper and manganesewere sufficient in these soils. The mapping of nutrients by GIS technique in the sub watershed revealed that, available N,P, S, Zn and Fe are important soil fertility constraints