Potassium release from soil separates of Kashmir

Non-exchangeable potassium release from ten different surface soils and their separates representing three altitude zones of Kashmir valley was studied. Higher quantities of potassium were released from soil and their separates using H⁺-resin than oxalic acid. X-ray diffractograms of clay fractions indicated the dominance of illite. Other minerals were mixed layer minerals, hydroxy interlayered vermiculite, kaolinite, chlorite, smectite and quartz and feldspars. Among different soil separates, clay fraction contributed the highest to the total potassium release using both H⁺-resin and oxalic acid. Sand and silt fractions contributed almost equal quantities to H⁺-resin, whereas in oxalic acid, sand fraction contributed more than silt fraction.