Agricultural Chemistry Section, Kota, Rajasthan
The medium black soils of Rajasthan have been found to contain on an average 1.7,6.7,10.0,110.0,500.0 and 688.7 mg of K/l00g of soil, the water soluble, available, exchangeable, fixed, HCl soluble and total K respectively. Average K fixing capacity has been found to be 7.46 m.e./l00g of soil. On the basis of the standard fixed by the I.A.R.I, the soil under study is low to medium with respect to available potassium. Water soluble and exchangeable K bears significant correlation with available, HCl soluble and fixed form of K. Highly significant correlation was found between fixed K and HCl soluble K and also between total K and available K.
Forms of soil potassium, potassium fixation