Site Specific Nutrient Management is a system for maximum yields in field crops. Nutrient Management Zones were developed for castor crop (Ricinus communis L.) in Inceptisols under semi-arid regions of India. Grids of 15 x 15 m were made in one hectare and soil samples were collected from each grid and were analysed for soil characteristics and all available nutrients. Based on analytical data the geo-statistical analysis varoni maps and different models like K-Bessel for pH, nitrogen, phosphorous and potassium, J-Bessel for E.C. Circular for sulphur, Spherical for zinc, Rational Quadratic for copper and manganese, Exponential for iron and Penta Spherical for boron with weak, moderate and strong spatial dependency were developed. The castor yield data was compared in nutrient management zones with farmers practice (FP) and recommended dose of fertilizers (RDF). The variable rates of fertilizers used by adopting STCR equation in SSNM was 92, 53, 15, 40 & 25 kg of N,P,K,S and Zn/ ha and 100, 40, 30 and 80, 40, 30 kg of N, P, K in farmers practice and RDF plots. The yields obtained with SSNM practice was 28 q/ha and 15 and 13 q/ha with RDF and farmer’s practice treatments respectively.