Forms of Potassium and K Fixing Capacity of Soils in Different Agro-Climatic Regions of Rajasthan

Distribution of different forms of K and K-fixing capacity was studied in the soils of different agro-climatic regions of Rajasthan. Water soluble and exchangeable K were highest in soils of arid and transitional regions. Fixed K which ranged from 18.4 to 160.0 mg/100 g soil was influenced by the type of K bearing minerals. High K fixation in soils of sub-humid and humid regions was governed by high amount of clay and proportion of vermiculite clay mineral. Potassium fixation significantly correlated with clay, silt, exchangeable K, fixed K and total K content of soils.