ecmn | Tech man - 11/4/2026 16:35
Anybody have any trial data testing potash rates before Soybeans? Can't seem to find much searching the web. Some background. We put our first pivot up last year. Next year half of that pivot will be beans. Now that water will not be our limiting factor on our sand looking to push bean yields. Talking with the head agronomist at our coop he says K will be our next limiting factor after looking at the grid samples. This is blow sand with CECs in the 5-6 range, OM 1.1-2.2 and K levels 52-80ppm. Will I see a ROI if i apply 3-400lb 0-0-60 this fall? I plan on leaving a couple check strips to find our for sure. Sure which I had a source of litter or manure around but we don't.
Become a manager of potassium, not just an applicator
What kind of diagnostics have you done for plant testing and other trials?
Have you done a total digestible assay? Or a couple samples to Haney have a few different workups of the soil done. It's not like any of them. Tests are not going to come back and be like dude, you have 42,000 lb of potassium in the soil. What are you even thinking. But they're going to come back at least give you a a bigger picture than just a simple soil test
I wouldn't get too hung up on that soil test number. If we were in southern or western Minnesota on prairie soils yeah, you'd be crying with them levels. You'd be a salesman's wet dream to see a soil test like that. But in your soils that number doesn't automatically mean you have a problem.
soil test is not an indicator of how much potassium is in the soil, and it is not how you build recommendations. It is a tool to predict a crop response to a fertilizer input. And we have to put it into the context of where you're farming.
Absolutely do application trials, but it'd be interesting to see where the first year of just being under the pivot comes in. Like if you don't panic and just apply potassium for 60 bushel beans, what happens.
The pivot is changing everything but it doesn't automatically mean you're going to be terribly deficient in everything.
The five and six CEC means you can't hold anything.
The University of Minnesota has a light soil potassium chart so 60 bushel beans on your soil they would say 80 to 120 lb of product
They recommend not trying to build past 120 parts per million on your kind of soil
You've been applying. And your soil test has been maintaining or not building. On your kind of soil I would be thinking that it's leaching?
And if leaching is a possibility I would move to more in season
To put down 400 lb would be a fun experiment on a couple acres, economically I would be a little nervous to do the whole farm.
But absolutely I would be doing strips. Start at 100 lb and work your way up to 400 lb.
Do some strips where maybe you split that into two applications.
The University of Minnesota has research that putting down too much. Potassium chloride actually hurts yields.
If the soil is having a hard time with the potassium, I would try a strip of apply the 120 lb but then do a few passes of potassium acetate or some type of high quality liquid potassium foliar feed leading up to r3 and a handful of passes after R3 three
I will send you kaden's phone number. You remember him from Willmar. He needs to go to the bar and find a wife because he spends way too much time thinking about nutrients and fertilizer. That boy is sharp.
https://extension.umn.edu/agriculture/crop-production/nutrient-manag...
Edited by easymoney 11/5/2026 04:18
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Potash before beans?
