Physico-chemical properties, available nutrient content and their inter-relationship in soils under rain fed maize-wheat cropping system, district Reasi (J&K)

Abstract

Composite soil samples representing rain fed maize-wheat cropping system in district Reasi of Jammu and Kashmir were analyzed for important physico-chemical properties and available nutrients. These soils were found to be sandy loam in texture with pH, EC and OC varying from 5.89 to 8.73, 0.04 to 0.47 dS/m and 3.5 to 21.9 g/kg, respectively. Content of available major nutrients viz. N, P, K and S varied from 207.6 to 663.6, 0.89 to 78.0, 22.71 to 349.45 kg/ha and 0.50 to 52.30 mg/kg, respectively, while that of available micronutrients viz. Fe, Zn and B varied from 0.89 to 30.20, 0.18 to 3.85 and 0.11 to 0.70 mg/kg, respectively. As per Nutrient Index values, these soils fell in high category of available Fe, medium category of available N, P, Zn, B and low category of available K and S. Soil pH, EC and OC were significantly and positively correlated with each other as well as with available N, K and B; and negatively with available Zn. Soil pH was also significantly negatively correlated with available Fe whereas, EC was positively correlated with available S and P. Further, available P was significantly positively correlated with OC, available N, K, S, Fe and B. Available N had a synergistic relationship with available K and B; and antagonistic relationship with available Zn. Available Zn showed significant and positive correlation with available Fe; however its correlation with available K and B was significantly negative. Available B had a significant positive correlation with available K and negative correlation with available Fe. The step down regression analysis indicated that nearly whole of variability in available N could be attributed to OC alone. About 28% of total variability in available P could be attributed to pH and EC together; while 13% of that in available S could be attributed to EC alone. Nearly 58 and 82% of the respective variability in available K and B could be due to OC and EC together. Soil pH and OC together contributed about 80 and 86% of the total variability towards available Fe and Zn in order.