How can we address a potassium deficiency in soil?

Asked May 16, 2014, 10:59 AM EDT

Our soil is below optimum in potassium. The recommendation states to add 0-0-60 fertilizer in the fall. Is there anything we can do now--in the spring before planting--to help? Also, we have the same question with regard to adding organic matter. The recommendation is to add compost in the fall. Is there anything we can do now? We usually get cow manure and till it in before planting. Should we continue doing that?

Livingston County Michigan

3 Responses

I don't know what your soil test recommendation is so I can't be really specific.

But potassium can be added, in most cases, BEFORE planting and then you till up the soil for the final time and give it about a week or so. Your entire recommendation for the year can be applied at that time, just like phosphorus, if you have to add that. Nitrogen MUST be divided into multiple applications to prevent burning plants.

Potassium moves through the soil very slowly and on its own, will drop about one or two inches a year, depending on your soil type.

Your soil test recommendation will give you a potassium number but this has to be adjusted to the potassium you are using. Your recommendation is for a non-existent product that is 100% pure. But you can only buy 0-0-60 or 0-0-52. This affects the amount you apply. It is a percentage.

Thanks for the quick response. Just want to be sure I understand. Right now our potassium number is 58ppm. Our recommendation says:

Potash (K > 50 ppm and K < 100 ppm)

Your potassium soil test level is low. In addition to the fertilizer suggested above, apply 2 lb 0-0-60 (or 5 lb 0-0-24) fertilizer per 1000 square feet in the fall and till in.
I'm not sure what you mean by "your recommendation is for a non-existent product that is 100% pure"? (Is it because I forgot to include the 2 lb/1000sq ft?
Also - should we continue to add the composted manure now, or wait until the fall??

Send me the code to your soil test because I can see what it says. It is a series of six numbers and capital letters. I can then open your test. Usually, tests don't break it down by pounds of a specific product on that first page. It is possible that you might have used the fertilizer calculator.