Q. If a grower has excess phosphorus or potassium, what are the steps to reduce those levels so they can start using compost and manure again?
A. For potassium, if you have any other cation that you can afford to add more of, like magnesium or calcium — without having excess amounts of them — that’s the easiest way to reduce potassium. If you can’t do that, the next easiest way is to use sulfur. It takes about one pound of sulfur to take out one pound of potassium — over and above what it takes to grow your crop.
So, potassium is more or less easy compared to phosphorus. I don’t know what to do to reduce excess phosphate except to grow it out. You quit adding whatever’s causing the levels to rise and then start growing crops like alfalfa or something that’ll pull a bunch of phosphorus out, and export that from that field.
From a recent Acres U.S.A. webinar with Neal Kinsey. Join our email list at acresusa.com to learn about all our educational products — articles, webinars, online courses, books, conferences, and more.
