Department of Agricultural Chemistry, Soil Science and Biochemistry, Orissa University of Agriculture and Technology, Bhubaneswar, Orissa, 751003.
Present addresses: 1RRTTS, G. Udaigiri, Khandamal, Orissa.
A study was conducted to assess the reserve and release of non-exchangeable potassium by repeated extraction with boiling 1 N HNO3 in twenty-one cultivated surface soils occuring widely in Narasinghpur area of Cuttack district. Potassium release parameters varied widely in different locations indicating a wide variation in K-supplying capacity of these soils. Total extractable K and total step K had positive correlation with each other. Both the K-release parameters were positively correlated with non-exchangeable K, lattice K and total K. Significant positive correlations of total extractable K and total step K with non-exchangeable K having ‘r’ value (r=0.944** and 0.989**, respectively) indicate that the non-exchangeable K may serve as a good index of the K supplying capacity of these soils.
Forms of K, total extractable K, step K, CR-K
