Soil fertility status of Nethakuppam watershed using RS and GIS

Abstract

Two hundred fifty soil samples from Nethakuppam watershed in Ramachandrapuram mandal of Chittoor district of Andhra Pradesh were drawn at 10 ha interval and analysed for fertility parameters. Analytical data was interpreted. 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 9.3.1. Soils were slightly acidic to strongly alkaline with non saline and soil organic carbon was low to medium. The available nitrogen (N) was low, available phosphorus (P) was ranged from medium to high and the available potassium was high and available sulphur was deficient to sufficient. Regarding available micro nutrients iron (Fe) and manganese (Mn) were deficient in about 3/4th of the watershed area whereas, available copper (Cu) and zinc (Zn) were sufficient in majority area of watershed soils. The fertility status in watershed revealed that, available N, S, Fe and manganese are important soil fertility constraints.