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Potassium (K) deficiency

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Bearswamper

A good 3 year old buck
My field has always required periodic applications of 0-0-60 to bring up K levels. With the cost of ferilizers through the roof (or even unobtainable for a time) I have started applying wood ash (hardwoods only) as an alternative since several members of the club have outdoor wood stoves. I started this winter on a 1/2 A plot and believe its too soon to determine it's effect. I know it didn't kill the clovers and chicory in this plot.
From my research :
* equivalent analysis = 0-1-3
* also contains ca
* apply @ 20#/ 1000 sq.ft (max/ year)- must be spread evenly
* do NOT apply during seeding (salt concentration will be too high)
* stored ashes must be kept dry to prevent the K from leaching out from rain
 
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I don't know where you need to go but it'll take a lot of wood ash to get you there. It might be a help but probably not much. Without regard to specifics, let's assume your K levels are 80 ppm, not terrible but not great. Suppose you want to raise the K ppm 50 ppm to 130.

In this game we assume the top three inches of soil weighs one million pounds. I think it's simple to see adding at the rate of 50 lbs will get you the additional 50 ppm of K.

If wood ash is 3% K then you will need 1,667 lbs of wood ash to add 50 ppm to the top three inches. Now double it to affect the top six inches of soil, the area where we do our best work and where 80% of a plant's root mass is located.

The other thing that concerns me about wood ash is its fineness. I don't know if it matters. I think it might. Potassium is a leachable element and I am tempted to wonder if you can keep it in the soil long enough to be helpful. Pure speculation on my part.

Note: ppm = parts per million.
 
Bearswamper said:
My field has always required periodic applications of 0-0-60 to bring up K levels. With the cost of ferilizers through the roof (or even unobtainable for a time) I have started applying wood ash (hardwoods only) as an alternative since several members of the club have outdoor wood stoves. I started this winter on a 1/2 A plot and believe its too soon to determine it's effect. I know it didn't kill the clovers and chicory in this plot.
From my research :
* equivalent analysis = 0-1-3
* also contains ca
* apply @ 20#/ 1000 sq.ft (max/ year)- must be spread evenly
* do NOT apply during seeding (salt concentration will be too high)
* stored ashes must be kept dry to prevent the K from leaching out from rain
Click to expand...
What have you been growing, and how have you been managing from year to year (tillage, burndown, always green?) ? If you can grow a full healthy stand of rye, you don't have a K problem. It's just not showing up on the soil test, and that could be because it's dry and mineralization has slowed to a crawl.
 
Thanks for the replies. I relied on the periodic soil tests to tell me what the soil needs and based on poor results with crops like radish and other brassicas ( stunted growth) I assumed that low K was the reason since the other elements were in sufficient supply. These are soil tests taken from different plots with-in the 5 A field at different times of the year. The original test yielded 49 PPM K through 12 sample locations. Some areas we have boosted amount of K to 128 ppm (highest) while other areas remain low -below 50 ppm.
Yes, you are correct that if a decent crop of WR can be grown (which has a high K demand) then the K must be sufficient.
The soil type is very fine sandy loam so perhaps the K leaches out quickly. To recap the field history- lot cleared in '40's, field corn planted from '50's thru '80's, planted Imperial clover first year introduced ~ '88? , let fallow other than brush-hog once a year, fertilized, diced, and planted WR w/ RC in fall '16, since then added adjacent plots expanding acreage to longtime fallow areas, as well as trying brassicas and other grains where RC died out. One parcel remains in the original RC with periodic overseeding as well as frost seeding. Funny thing is some of these new areas have higher K readings than the main field that has seen crop rotation and more amendments. Unless where Clover is planted, plots were disced where brassicas or grains were to be rotated. FWIW soil tests were by Penn State and the "real" farmer of the group showed us the proper procedure.
Am I placing too much concern over test results
 
A soil test is a distant light in the dark. Let's go back to the top 6-inches of soil where we traditionally call it 2-million pounds. How does one adequately and randomly sample that much soil? You don't. A soil sample is just some information that will hopefully help you do better. It's helpful to remember a soil sample gives an average of the amount sampled. There's always great variability within a field. K levels might be 30 ppm in one section and 190 in another...and everything inbetween.
 
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Bearswamper said:
Thanks for the replies. I relied on the periodic soil tests to tell me what the soil needs and based on poor results with crops like radish and other brassicas ( stunted growth) I assumed that low K was the reason since the other elements were in sufficient supply. These are soil tests taken from different plots with-in the 5 A field at different times of the year. The original test yielded 49 PPM K through 12 sample locations. Some areas we have boosted amount of K to 128 ppm (highest) while other areas remain low -below 50 ppm.
Yes, you are correct that if a decent crop of WR can be grown (which has a high K demand) then the K must be sufficient.
The soil type is very fine sandy loam so perhaps the K leaches out quickly. To recap the field history- lot cleared in '40's, field corn planted from '50's thru '80's, planted Imperial clover first year introduced ~ '88? , let fallow other than brush-hog once a year, fertilized, diced, and planted WR w/ RC in fall '16, since then added adjacent plots expanding acreage to longtime fallow areas, as well as trying brassicas and other grains where RC died out. One parcel remains in the original RC with periodic overseeding as well as frost seeding. Funny thing is some of these new areas have higher K readings than the main field that has seen crop rotation and more amendments. Unless where Clover is planted, plots were disced where brassicas or grains were to be rotated. FWIW soil tests were by Penn State and the "real" farmer of the group showed us the proper procedure.
Am I placing too much concern over test results
Click to expand...

Has everything struggled in that soil, or just the brassicas?


Sent from my iPhone using Tapatalk
 
Yes, just the brassicas. First year that we tried dwarf essex rape it came in pretty well - until the deer tasted it. Radish never gets bigger than thumb size and does not come in with any density -very few plants per sq ft. and the game cams do not show them browsing much on the radish leaves. What does grow well- clovers, chicory, WR, oats, buckwheat, sorghum.
I understand about variability of soil samples but with-in a 1/2 A plot I take 8 samples and thoroughly mix them. Also, monitoring these soil tests, the K levels come back up when 0-0-60 is added. Then in 3 years when re-tested the K levels are down again probably because it leaches in sandy soil.
 
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