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Joliet, IL

i am wondering how concerned i should be with my potassium levels so high. last year i had early maturation that i figured was due to the crazy high temps. now i am thinking that it was due to this higher level of potassium. i used a high potassium fertilizer 5-10-40, 3 years ago and also the 2 years prior to that in liberal amounts, which i figure is where the high level of K is coming from. here are my test results.

ph=7.5
OM=9.2%
base saturation:K=10.7%,Mg=16.6%,Ca=71.6%
CEC=27.5

also, should i mess with trying to bring my ph down a bit by adding some sulfur and trying to achieve a range between 6.5 and 7.0?

any thoughts or suggestions are greatly appreciated.
shaz

4/13/2006 6:40:21 PM

Ctpumpkin@optonline.net

shaz,

Bring the Calcium up with Gypsum if the levels are low enough to justify the effort. I don't see a ppm or lbs/A here.

4/13/2006 7:13:14 PM

Joliet, IL

Steve, here are my ppms as listed on my soil test results:

P1=166 ppm
P2=250 ppm
K=1148 ppm
Mg=549 ppm
Ca=3934 ppm
Na=69 ppm
Nitrate-N= 69ppm
S= 999 ppm
Zn= 20.4 ppm
Mn= 14 ppm
Fe= 56 ppm
Cu= 2.0 ppm
B= 2.7 ppm

4/13/2006 7:26:56 PM

Mocksville, NC

just balance with higher phosphate folier 10-50-10 peters just a thought being so close to planting time, no expert here, just my 2 cents Roger

4/13/2006 9:46:07 PM

Hudsonville, Michigan (michiganpumpkins@sbcglobal.net)

Shazz:
Let's compare notes because my soil test is similar to yours this spring. (And I'm not happy about my K levels either.) How much change is this from last year? And, what did you put in last fall?
Lots of fresh cow manure? Compost?

I say yes to the sulfur. Maybe about 20 lb per 500 sq. ft. And yes to gypsum. 80 lb per 500 sq ft. Bumping up calcium would bring your Ca:K ratio back in line some. Not sure how quickly K leaches, or whether you can plant something that would take some out? Anyone know?
Frank

4/13/2006 10:29:08 PM

Hudsonville, Michigan (michiganpumpkins@sbcglobal.net)

Your
Ca:K is 3.4:1 (15:1 is ideal)
Ca:Mg is 7.1:1 (10:1 is ideal)
Mg:K is 1:2 (2:1 is ideal)

Your raw numbers are high but the ratios are more important...

4/13/2006 10:35:20 PM

Joliet, IL

embarrassed to say it Frank, but after 5 years of growing this was my first soil test. I put in 4-5 inches of compost early this spring from a local composting company that converts yard waste into compost. it is accreditted by the national composting association. for the past 3 years i have put on mushroom compost and well aged manures along with lots of shredded leaves. i have stayed away from chem ferts on the most part for the past 2 years.

4/13/2006 11:00:01 PM

Joliet, IL

Frank, I have read aluminum sulfate will lower the PH to a more desirable rate faster, but some say to stay away from it due to possible aluminum toxicity. if i went with just a fine sulfur, this would take longer than the upcoming growing season to get it back down. my irrigation water, city water, has a ph about 7.5, and with no rain last year, i am sure this is why my ph is where it is at. any thoughts about the aluminum sulfate for a quick fix? i know peat moss is also a long term solution and i am going to till some in on my final spring till along with some more gypsum. still not sure about the aluminum sulfate though until i get some more response.

4/13/2006 11:07:08 PM

Puyallup, WA

I found that high K levels can drop rapidly. I had high K levels due to "mucho" chicken manure. My Fall of 2002 readings were 1383 ppm. By the Fall of 2003, it was 668 ppm. Fall of 2004, it was back up to 1313. By Spring 2005, it was down to 572....yep, you read it right...a drop of over 700 ppm in just five months!!!!!

4/13/2006 11:08:30 PM

Ctpumpkin@optonline.net

Shaz,

"for the past 3 years i have put on mushroom compost and well aged manures....."

This sheds a lot of light on things. The mushroom compost delivered the potash.

Add some Gypsum or do nothing. Don't lose sleep over the ratios since all of the minimums are more than met & the ratios are close enough. Grow well.

4/14/2006 7:07:17 AM

Hudsonville, Michigan (michiganpumpkins@sbcglobal.net)

Good news from Stan that K can vary widely over the course of a season. Also good to note that during the 2002-2005 timespan, Stan has kicked butt even with high K in his dirt. At least 9 over 1000 in that time. So there is hope for us, Jeff!
I've also heard that the aluminum sulfate is quicker in lowering pH, but I don't think you want it to change too rapidly...don't want to shock your soil. 7.5 isn't terrible anyway, and if it lowers slowly over the next few months to 6.8 or 7, you'll be just fine. By the way, the amount of sulfur you should put down depends also on your soil texture. It takes more sulfur to move pH in clay, less for sandy soil. Check on rate of application with someone who knows more about it than me!
I put in some fresh cow manure and compost last fall and tilled in. Not sure whether the manure or the compost brought my K up from 528ppm to 822ppm. The manure is the more likely culprit, but I put manure in every fall, and never a bump like that on K. So the compost may have been partially to blame.
As I recall you usually start yours pretty early down there. How soon until your plants will be outside?

4/14/2006 7:16:08 AM

Mocksville, NC

1/2 pound organic elamentel sulfer per 500sqft 7.5 is ok but locks up some nutrients at this rate you will bring it closer to you target, and it takes a little time about 4 weeks, and let mother nature do the rest you might have been higher when you grew your 885 shnoah

4/14/2006 7:43:05 AM

Joliet, IL

been off the computer for a week Frank. i started an early plant last year on april 1st and my fall plants on april 28th. this year no early plants, just an april 28th start for my 4 plants. thanks for the help everyone, i have decided to throw down some gypsum and sulfur, and will be tilling that in tomorrow. best of luck all.

4/21/2006 4:56:48 PM

Midwest

Shazzy,

With high potassium level combined with low calcium level... potentially you get luxuriant plant growth, but also a plant that is susceptable to stress and disease. Gro a Giant! Best wishes!

4/25/2006 11:59:31 PM