Forms of Potassium in Some Soils of Assam in Relation to Soil Properties

Forms of potassium and their relationship with soil physico chemical properties were investigated on sixteen representative surface samples of alluvial (Inceptisols) and lateritic (Alfisols) soils of Assam. Alluvial soils contained relatively higher amount of total, non-exchangeable and lattic K as well as higher K-fixation capacity vis-a-vis lateritic soils. Available K as measured by water soluble and exchangeble forms were higher in lateritic soils. Different forms of potassium and K-fixation capacity showed a positive relationship with clay, silt, organic carbon, CEC and base saturation and negative relationship with sand. In respect of pH, water soluble, exchangeable, non-exchangeable K and K-fixation capacity showed positive relationship whereas total and lattice K showed negative relationship.