Too much Potassium (K)

[bueller]

Shame on me for not taking a soil sample a few weeks before planting. So when I went to the Co-Op to get fertilizer and lime I went pretty safe with two bags of 17-17-17. Unfortunately I didn't realize that they gave me one bag of 17-17-17 and one bag of 0-0-60 until I got back to my place. Our sand is usually low on K so I put it down anyways. This was on a 1/2 acre so I added about 77 lbs of K per acre to my plot. Well soil test is back and apparently my previous soil building has worked as no K was recommended. Are there any negative effects to adding excess K and will it remain available or go to waste?

 

[bueller]

The 6.1 pH was a bit of a surprise also. I don't think I'll be shoveling and throwing lime again anytime soon. Everything has come a long way since this plot was created in the spring of 2015.

 

[S.T.Fanatic]

As far as if it will remain available depends on your Cation Exchange Capacity which I don't see listed. The optimum range of Potassium (K) for soybeans for instance is between 180-200 ppm. So in that case if you have sandy soil and planted soybeans some will be lost but you should keep well within the optimum range.

 

[Ben Glantz]

Am I reading the soil test wrong or did you sample 2 plots? One says pH is at 6.1 and the other says 5.5? Where did you get the test done, I like the recommendation of lime per 1000sq feet.

 

[bueller]

Am I reading the soil test wrong or did you sample 2 plots? One says pH is at 6.1 and the other says 5.5? Where did you get the test done, I like the recommendation of lime per 1000sq feet.

Same plot. First tested in spring of 2015. Re-tested 10 days ago. I went from 5.5 up to 6.1 with one application of lime in 2015 and just added 2400 lbs/acre of lime after pulling the recent sample but before getting the results. I use Biologic for the tests. $7.95 plus a stamped envelope and a zip lock bag is all it costs me. Results are emailed back about 5 days after I drop the envelope in the mail.

 

[Ben Glantz]

ahhh, now I get it, thank you. That is a great increase in PH and that is a good price for the soil sample!

 

[FarmerDan]

I would love to have 248 lbs of K per acre. if I understand all I know (and even some of what I don't) that's still only 124 ppm. Wait! Then you add 77 lbs of 0-0-60? You'll be just dandy. When a soil test says optimum -- it can mean many things. Mostly it means addition of additional amounts of this nutrient will not result in a yield response. It's still OK to build soil nutrient levels. Kinda' like money in the bank. How well your bank will protect your investment, that's another question. Sand leaks. If there's some OM it will leak less. If the pH is (here we go again) optimum, that's better. Keep the plot planted. That will help. Did you waste money? Savings is in the wallet of the beholder.

 

[Crimson n' Camo]

I think you will find that you WILL have to add more lime in the next couple of years....but it'll be for a good reason....because the soil will hold more. I started off at 300 lbs of Ca.....moved to 900 lbs.....and then to 4,000 lbs after my last lime application....After you build more OM, then the soil will start calling for more lime to fill your bucket on up.

 

[SD51555]

I'm putting on 350lbs of potash/acre this year. I've got a CEC of 8. I'm curious to see if I can hold it come next fall. I was low. 350lbs should put me at 6% base saturation. We'll see how it goes.

 

[bueller]

I'm putting on 350lbs of potash/acre this year. I've got a CEC of 8. I'm curious to see if I can hold it come next fall. I was low. 350lbs should put me at 6% base saturation. We'll see how it goes.

That seems like a lot

 

[S.T.Fanatic]

I'm putting on 350lbs of potash/acre this year. I've got a CEC of 8. I'm curious to see if I can hold it come next fall. I was low. 350lbs should put me at 6% base saturation. We'll see how it goes.

That's exactly where crops like rye and radishes come to the rescue. If you do end up having some of the nutrients leach into the ground the rye and radishes will pull it back up.