Soil fertility status in Brahmanakotkur watershed of Andhra Pradesh for site specific recommendations

Abstract

Two hundred thirty one soil samples from Brahmanakotkur watershed in scArce rainfall zone of Andhra Pradesh were drawn at 320 m grid interval and assessed for their fertility parameters. Analytical data was interpreted and statistical parameters like range, mean, standard deviation and coefficient of variation were calculated. Soil fertility maps were prepared for each parameter under GIS environment using Arc GIS v 10.3. Soils were neutral to strongly alkaline with non-saline in nature and soil organic carbon content was low to medium. The available nitrogen (N) was low to medium, available phosphorus (P) and potassium (K) were low to high and available sulphur (S) was deficient to sufficient. Regarding available micronutrients, zinc (Zn) and iron (Fe) were deficient in about 3/4th of the sub-watershed area whereas, available copper (Cu) and manganese (Mn) was sufficient in the soils. The fertility status of nutrients in watershed revealed that, available N, S, Zn and Fe are important soil fertility constraints.