Potassium fixation capacity and potassium release of representative soil series of sub-Montane zone of Maharashtra

The representative soil series of order Entisols, Inceptisols and Vertisols collected from agriculture college Kolhapur and different research stations of Sub-montane zone of Maharashtra were assessed for potassium fixation capacity and potassium release. The K-fixation in different soils ranged from 78.80 mg kg-1 (Kurkum series of A.R.S., Vadgaon-Maval) to 276.40 mg kg-1 (Koregaon series of A.R.S., Karad). From the mean values, it was observed that Vertisols showed highest K fixation capacity followed by Inceptisols and Entisols. All the soil series were categorized as very low in step K except Koregaon series of A.R.S., Karad of Vertisols. The sub-surface horizon showed higher cumulative step K release than the surface horizon. The step K release studies pointed out that limited pool of non-exchangeable K was available to crops if these soils are placed under intensive cropping. The step K and constant rate K was highest in Vertisols followed by Inceptisols and Entisols.