Effect of Long Term Fertilization with Nitrogen and Phosphorus on Q/I Parameters of Potassium of an Inceptisol under Intensive Cropping System

Q/I parameters of potassium in soil were affected by long-term intensive cropping and application of N and P fertilizers without addition of K. AR_o^k value, an index of availability of potassium was drastically reduced in soils of N and P fertilized plots, showing decrease in potential with respect to immediate K availability. K adsorption was also more in such plots indicating greater need to satisfy larger K depletions. Out of the total labile K, major amount was associated with stronger bonding sites in the soil samples of the highly K-depleted plots.