Thanks for the reply and heads up. I was looking into more potash and K as well and it appears that some of the better CEC soils can exchange more K, which means apply less K there, and instead apply more K to the poorer CEC areas. I guess I first need to finisn mapping all m fields with the veris and then figure out after that more testing to keep making my variable rate inputs go down. I feel the biology won’t be much different, trying to determine which nutrients are lacking and why using sap testing is now a part of the plan as well, rather than just trying to “replace” soil nutrition. I did do several tissue sampling projectds last year, and found corn to be deficient in boron, low in zinc, nitrogen, and sometimes other micros. I’im curous how sap testing will compare this year and show me differences… Thanks!