jbgruver - 3/20/2013 19:57 I have seen data showing 20-30% uptake of the K in KCl by the following crop. I have also seen much higher numbers. KCl is very soluble so the potential availability is quite high... The % uptake of fertilizer K by the next crop is a function of many things other than solubility such as the placement of the K fertilizer, the abundance of indigenous soil K and other soil cations, soil CEC and the presence of clay minerals such as illite that can "fix" K between clay layers. % uptake of fertilizer K is normally higher if soil test K levels are low and if the K is banded. Joel WIU Agriculture