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Lightweight Peat's Mucky Muck soil testing
- Thread starter biggreg
- Start date
biggreg
Member
Let's think on how the Mehlich 3 test works:
The lab takes your sample and dries it. Once it's bone dry, they grind and pulverize it, pass it through a 2mm sieve and then measure 2 grams into a flask with 20ml of Ol' man Mehlich's special sauce, shake it for 5min in a shaker then pour it into the ICP.
The ICP gives a report on micrograms of element per 10ml of of sauce.
Lab used 2g soil to 20ml so 1g to 10ml is the ratio.
So micrograms of element per 10ml sauce = micrograms per 1 gram of soil
A microgram is 1/1millionth of a gram or 1 part per million.
Microgram per gram = milligram per kilogram = gram per ton
Ppm = 1/1million
To convert this to lbs/acre slice, one has to know bulk density.
The math is way easy when the BD = 1, The conversion to lbs/acre is even easier when you don't actually measure the BD and just assume all soil has a density of 1.
The lab takes your sample and dries it. Once it's bone dry, they grind and pulverize it, pass it through a 2mm sieve and then measure 2 grams into a flask with 20ml of Ol' man Mehlich's special sauce, shake it for 5min in a shaker then pour it into the ICP.
The ICP gives a report on micrograms of element per 10ml of of sauce.
Lab used 2g soil to 20ml so 1g to 10ml is the ratio.
So micrograms of element per 10ml sauce = micrograms per 1 gram of soil
A microgram is 1/1millionth of a gram or 1 part per million.
Microgram per gram = milligram per kilogram = gram per ton
Ppm = 1/1million
To convert this to lbs/acre slice, one has to know bulk density.
The math is way easy when the BD = 1, The conversion to lbs/acre is even easier when you don't actually measure the BD and just assume all soil has a density of 1.
acespicoli
Well-known member
If it were me I would start with this:
Guidelines for Taking Soil Samples
Do not wait until the last minute. The best time to sample is in the summer of fall.
Take cores from at least 15 to 20 spots randomly over the field to obtain a representative sample. One sample should not represent more than 10 to 20 acres.
Sample between rows. Avoid old fence rows, dead furrows, and other spots that are not representative of the whole field.
Take separate samples from problem areas if they can be treated separately.
In cultivated fields, sample to plow depth.
Take two samples from no-till fields: one to a 6 inch depth for lime and fertilizer recommendations, and one to a 2-inch depth to monitor surface acidity.
Sample permanent pastures to a 3- to 4-inch depth.
Collect the samples in a clean container.
Mix the core samplings, allow to air-dry, and remove roots and stones.
Fill the soil test mailing container.
Complete the information sheet, giving all of the information requested. Be sure to include the soil name. Remember, the recommendations can be only as good as the information supplied
I just cant help but to notice this point
Guidelines for Taking Soil Samples
Do not wait until the last minute. The best time to sample is in the summer of fall.
Take cores from at least 15 to 20 spots randomly over the field to obtain a representative sample. One sample should not represent more than 10 to 20 acres.
Sample between rows. Avoid old fence rows, dead furrows, and other spots that are not representative of the whole field.
Take separate samples from problem areas if they can be treated separately.
In cultivated fields, sample to plow depth.
Take two samples from no-till fields: one to a 6 inch depth for lime and fertilizer recommendations, and one to a 2-inch depth to monitor surface acidity.
Sample permanent pastures to a 3- to 4-inch depth.
Collect the samples in a clean container.
Mix the core samplings, allow to air-dry, and remove roots and stones.
Fill the soil test mailing container.
Complete the information sheet, giving all of the information requested. Be sure to include the soil name. Remember, the recommendations can be only as good as the information supplied
I just cant help but to notice this point
biggreg
Member
If it were me I would start with this
Thank you for cutting and
pasting field soil sampling guidelines.
biggreg
Member
The idea is to get a representative sample of your average soil and to get it to the lab without contaminating it or otherwise causing interference with the test.
For container soil, get several scoops from various parts of your pile, bed, large container or whatever batch you want tested. Remove roots, leaves, mulch, large unsual rocks, old wedding rings, bottle tops off of bottled woo juice, etc. don't tweak and pick about all your pumice and rice hulls or perlite. Your sample should represent your soil as it is.
Don't use your rusty scoop or shovel to dig it up either ( Fe contamination)
Don't have powder fertilizer next to a fan blowing on your sample.
Just be careful with it.
Don't hand wash your clothes in borax before sampling with wet bare hands.
For container soil, get several scoops from various parts of your pile, bed, large container or whatever batch you want tested. Remove roots, leaves, mulch, large unsual rocks, old wedding rings, bottle tops off of bottled woo juice, etc. don't tweak and pick about all your pumice and rice hulls or perlite. Your sample should represent your soil as it is.
Don't use your rusty scoop or shovel to dig it up either ( Fe contamination)
Don't have powder fertilizer next to a fan blowing on your sample.
Just be careful with it.
Don't hand wash your clothes in borax before sampling with wet bare hands.
biggreg
Member
What else about sampling should we consider?
How about incubation period after last re-amend?
We must give any amendment enough time to "cook" or "settle-in" to the soil before we test it.
How long should we wait?
Good question
For field cultivation, I've seen 6 months after liming mentioned in a lab manual. Some labs will give lime credit for last years lime that hasn't reacted.
That is in the field
In containers, we may mix the amendment more thoroughly and maybe use micronized lime. We also can control moisture and temp and biology better than our out-door brothers. so our incubation time is shorter.
How short? Hell if I know.
How about incubation period after last re-amend?
We must give any amendment enough time to "cook" or "settle-in" to the soil before we test it.
How long should we wait?
Good question
For field cultivation, I've seen 6 months after liming mentioned in a lab manual. Some labs will give lime credit for last years lime that hasn't reacted.
That is in the field
In containers, we may mix the amendment more thoroughly and maybe use micronized lime. We also can control moisture and temp and biology better than our out-door brothers. so our incubation time is shorter.
How short? Hell if I know.
biggreg
Member
The ICP machine measures the micrograms of elements per 2g gram of soil extracted with 20ml of sauce. Divided in 1/2, and we have measured the micrograms of our extractable elements per gram of air dried soil.
So how does the ICP measure the elements in the sauce? Hell if I know, something using plasma, I'd suppose. Doesn't matter. It works.
Q: How can such a tiny sample tell us anything about our whole soil?
A: good question and here is part of it: the exchange capacity of the soil is held on tiny clay and/or humus colloids that are suspended in the soil solution. The electrostatic nature of the elements in this solution achieve a balance and it's pretty uniform for a given batch.
Q: what about the micros and anions?
A: I don't know. Quit asking so many questions. It just works, ok?
So how does the ICP measure the elements in the sauce? Hell if I know, something using plasma, I'd suppose. Doesn't matter. It works.
Q: How can such a tiny sample tell us anything about our whole soil?
A: good question and here is part of it: the exchange capacity of the soil is held on tiny clay and/or humus colloids that are suspended in the soil solution. The electrostatic nature of the elements in this solution achieve a balance and it's pretty uniform for a given batch.
Q: what about the micros and anions?
A: I don't know. Quit asking so many questions. It just works, ok?
neverforget4/20
Member
I test my soil on the reg and go with the recs. On this recent test the only rec i got for this batch was to try out some feather-meal and observe response. I followed their suggestion and all is well. This is a well recycled peat based mix.
Im interested to learn more about interpreting test results. Would you please comment or make observations about my mix. Thanks for your keen interest in testing.
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biggreg
Member
We can try to look at it together but I'm mostly familiar with the Mehlich 3 at this point.
neverforget4/20
Member
Thanks man. I thought this was an M3. It's the basic test that is offered at Logan
neverforget4/20
Member
That soil was well baked, it was covered with alfalfa straw but no amendments for over 12 weeks (warm weather). It is a mineralized soil. Mostly peat but plenty of biochar and shell. I followed the practices of international ag labs who use an Albrecht approach.
I used the ordinary form that logan has online. I didn't make any arrangements.
I used the ordinary form that logan has online. I didn't make any arrangements.
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biggreg
Member
Copy.
Using that same methodology,
You need Ca, but you don't need an ph increase and you could use some sulfur so Gypsum it is. Use gypsum to hit your Calcium target ratio.
Phosphorus is low, bring up to their ideal K suggestion around 400ppm.
Sulfur up to about 300 would work
Boron up to 1/1000th of your target Ca.
The other micros seem to be in well enough balance to leave alone for now.
Using that same methodology,
You need Ca, but you don't need an ph increase and you could use some sulfur so Gypsum it is. Use gypsum to hit your Calcium target ratio.
Phosphorus is low, bring up to their ideal K suggestion around 400ppm.
Sulfur up to about 300 would work
Boron up to 1/1000th of your target Ca.
The other micros seem to be in well enough balance to leave alone for now.
neverforget4/20
Member
Thanks man,
Appreciate your observations. Do you agree with the feather-meal recommendation for N?
Appreciate your observations. Do you agree with the feather-meal recommendation for N?
biggreg
Member
Because of the standard scoop they use, You should probably ignore bulk density and just convert needed ppm to grams of amendments as if the density was 1.
This seems to have worked close enough for me with the way they have been testing most soils.
If the test had the sample weighed in, the ratios would be the same but the ppm values would be higher. You would have to use a bulk density to figure mass of amendments per volume.
Also, I'm not real comfortable with reccomendations, all i can do is point to what books say. Most of my growing career has been more guessing than anything. I'm just starting with this testing and correlating and calibrating stuff. I have no practical experience as to which methodology of interpreting soil test results works.
I'm just a guy with some technical background who doesn't like numbers that don't work. These scoop tests with their lower than expected readings and CEC really got under my skin.
This seems to have worked close enough for me with the way they have been testing most soils.
If the test had the sample weighed in, the ratios would be the same but the ppm values would be higher. You would have to use a bulk density to figure mass of amendments per volume.
Also, I'm not real comfortable with reccomendations, all i can do is point to what books say. Most of my growing career has been more guessing than anything. I'm just starting with this testing and correlating and calibrating stuff. I have no practical experience as to which methodology of interpreting soil test results works.
I'm just a guy with some technical background who doesn't like numbers that don't work. These scoop tests with their lower than expected readings and CEC really got under my skin.
