Investigation about potassium status and its relationship with mineralogy and soil properties in Kaftar region Fars Province

This study was conducted to investigate the status of soil potassium including different K forms, in soils and their relation to chemical and mineralogical properties of soils in soil orders and different physiographies unites of Kaftar region, Fars province. The study showed that the region soils were in four soil orders: Alfisols, Vertisols, Inceptisols and Entisols. Smectite, chlorite, illite, quartz, and interstratified minerals were detected in the clay fraction of the studied soils. The average of soluble, exchangeable, non -exchangeable, structural, and total K in the studied soils were 3.22, 510, 1013, 5568 and 7095mg kg-1, respectively. The average amount of soluble K in surface and subsurface horizons in low land physiography and exchangeable and non-exchangeable K in piedmont plain were higher than the other physiographies units, and the content of total and structural K in Alfisols were higher than the other soils. Also, there were significant differences between K pools in different soil orders. Comparison of K forms distribution between different soil orders revealed that Vertisols and Alfisols had higher amounts of different forms of K than those of other soil orders. Also, the amounts of K pools were lower in Entisols than other soil orders.