You are correct, DPTA is the process that they use when running AA@pH 7 and the DPTA is run at a pH of 7.3 I believe.
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Lightweight Peat's Mucky Muck soil testing
- Thread starter biggreg
- Start date
You are correct, DPTA is the process that they use when running AA@pH 7 and the DPTA is run at a pH of 7.3 I believe.
biggreg
Member
Other procedures for extracting micros will never give the same valuie as the Mehlich 3. All soil test are just values indexed to crop response. DTPA or hot water Boron, etc will never match the Mehlich 3 value. That's not how it works with the Phosphorus tests or the micro extractions according to the lab manuals.
The base cation test M3 vs AA 7.0 or 8.5 should in theory displace the cations attached with ammonium.
Without intference from free carbonates or salts, they should agree closely, assuming the test was executed correctly.
K and sometimes Mg come close comparing AA@8.2 vs M3. Sometimes Mg is way off. Ca is always the big wild card. Sometimes even in neutral soils where there are lots of calcium carbonate rock present the difference between M3 and AA@8.2 is great. We even found some bicarbonates one time, this is because of the very low rainfall in that area, Zacapa valley Guatemala. When I worked there 25 year ago, it was a soil that always left us very confused, getting good prolonged response there in melons was very difficult. They have huge bicarbonate levels in the water (over 5 meq) and the soil reacts to muriatic acid at about 20 inches down. Lots of white and creamy colored, red stained rocks.
As for P, well, the correlation between high P here and yields is pretty impressive using M3 on alkaline soils!
These are the recommendations concentrates northwest gave me for that a&l lab test. I know you cant make calls on amendments with just dpta but are you applying similar amounts of limestone at these recommended rates on native jory?. You think they would get us to 70% base saturation minimum or even close?
Apply the following per 1000 sq. ft. / 3015 sq. ft.:
180#* Limestone (Not Dolomite)
28.3# Feather Meal
5# Fish Bone Meal
4.8# Sulfate of Potash
As a substitute for the feather meal, fish bone meal, and sulfate of potash, you could use a pre-mixed fertilizer we carry. I’d recommend 50# of the “Nature’s Intent 7-2-4.”
*The key to applying this much lime or dolomite is that it must be worked into the soil to a 6"-8" depth. If you don't till in the lime, you should limit the application to 90# per 1000 sq. ft..
For trace nutrients, I generally recommend the following per 1000 sq. ft.:
#10 Kelp Meal
#10 Rock Dust (Ex: Cascade Minerals, Glacial Rock Dust, Azomite, or Greensand)
The test also noted that you have low Boron levels, but applying kelp over the next 5 years should correct the deficiency. If you want to make a one-time application of boron
The local university and many others run the AA@pH 7 procedure and the DPTA at pH 7.3 The labs tend to utilize "the package" of procedures for specific pH soils. Correct? Those two go hand in hand.
The point is that I need to know which specific metals are there and how much of those metals there really are at a pH similar to that of root exudates. M3 is a pH of 2.5 I believe.
When using the alkaline soil package and reactants working at alkaline pH's, you can't balance metals as you have no idea of the real quantities of metals in that soil.
Run DPTA and M3 on the same soil and you can find 30 times more Fe and more in the M3 procedure vs AA@pH 7.
biggreg
Member
I can agree limestone based sands interfere with the test.
The interference would be similar for M3 and 7.0.
You reccomend the AA 8.2 with a Mehlich 3 for every acidic and alkaline soil?
Are you doing these two tests to find a more true value for the Ca actually attached to the exchange sites in order to better calculate the CEC for a ratio based approach?
When I get called in, it is because someone has a problem. I get response. I can't get response underestimating by 50 times or more what I need. Doesn't matter if there are free elements not bound in the soil. Here we can start at a pH of 8.2 or so. Why wash everything away, why not take advantage of it?
I'll tell you why they don't try to take advantage of it, because the conductivity is "high". Yet, when we have enough Ca, crops can tolerate higher conductivity. Read up on the SAR ratio of water. It works on soils. Just in soils we call it the base distributions.
biggreg
Member
A higher M3value vs DTPA does not mean there is more or less in the soil. They cannot be directly compared. It's similar to the P extractions, they all index to plant response but have differing values. Some of the P extractions have conversion multipliers to each other.
Also,
Ammonium displaces the cations in a process is that is ph independent. That is how it works at the Mehlich 3, 2.5 ph or Aa7.0ph or aa8.5ph Don't let the ph confuse us.
And Also,
We are talking Bradley's Jory acid silt clay loam. Not alkaline soils. Not calcerous limestone sands in acid soils. My question to you wasnt related to micros or Phosphorus solublization or chelation of micros at low ph or alkaline soils. Lots of answers that sound good but a more topic focused answer would be more beneficial to all in the future with other discussions.
This discussion is done.
Biggereg is wrapping this up due to lack of interest or fruitful beneficial participation.
I wish you all luck on your growing endeavors.
My final message is:
Don't let the bastards "scoop" you if you want a real test!
( especially 1/2 scooping Spectrum analytics )
_tessarecting
ஓ
I'd be interested in hearing about how we could use the community effort of icmag to develop some way of moving forward and possibly resolving this conundrum???
After the jory soil talk obv
After the jory soil talk obv
_tessarecting
ஓ
plantingplants
Active member
I think these are the geekiest most niche memes I've ever seen.
Damn man, I can't help but feel like I doomed this thread when I landed here. 
biggreg 
thanks for sharing your info 
biggreg thanks for sharing your info 
acespicoli
Well-known member
test ammend test. Accuracy vs Precision
Thats what I learned thanx biggreg
Excellent thread!
Thats what I learned thanx biggreg
Excellent thread!
neverforget4/20
Member
cannabisforjoe
New member
big thanks for all your hard work
big thanks for all your hard work
biggreg,
thanks for all of the time you put in to this. it really is a shame how many corners are cut by these labs and how little they care. while i have never used them, i have also always wondered why tests from spectrum never added up properly in regards to base saturation. though not that surprising when you read that they don't put much stock in albrecht type bcsr. keep up the good work
Joe
big thanks for all your hard work
biggreg,
thanks for all of the time you put in to this. it really is a shame how many corners are cut by these labs and how little they care. while i have never used them, i have also always wondered why tests from spectrum never added up properly in regards to base saturation. though not that surprising when you read that they don't put much stock in albrecht type bcsr. keep up the good work
Joe
plantingplants
Active member
Biggreg, i posted this in slownickel"s thread but thought you may be interested. Dont know if you saw but SN got spectrum to weigh 2g samples for only an extra $10.
Here are two results from the same sample plus the base distros I calculated with AA8.2 Ca- the first is the scooped results, the second is weighed and whatever else they do for k3. This soil is roughly 80% lighter than 2,000,000 lb acre soil.
CEC .. 17.7*
K 0.93 .. 5.2%*
Mg 4.4 .. 24.8%*
Ca 12.2 .. 68%*
Na 0.19 .. 1%*
40.1 cec
74% ca
20% mg
4% K
0.6% na
Very confused as to why some numbers didn't move at all. Like fe.. 1 ppm??? Doesn't make sense to me.
Here are two results from the same sample plus the base distros I calculated with AA8.2 Ca- the first is the scooped results, the second is weighed and whatever else they do for k3. This soil is roughly 80% lighter than 2,000,000 lb acre soil.
CEC .. 17.7*
K 0.93 .. 5.2%*
Mg 4.4 .. 24.8%*
Ca 12.2 .. 68%*
Na 0.19 .. 1%*
40.1 cec
74% ca
20% mg
4% K
0.6% na
Very confused as to why some numbers didn't move at all. Like fe.. 1 ppm??? Doesn't make sense to me.
plantingplants
Active member
I think they must be limiting it still because if you use the AA8.2 Ca value in the CEC calculation then it goes from 17.7 to 40.1...... but yea seems like everything should shoot up a lot more, but maybe by grinding everything finely, the soil weight difference goes down.
Thank you for your input. Where do you like to see N?
btw, the NO3 horiba meter on Amazon I'm looking at goes from 62ppm to 6200ppm. I see there are meters with different ranges. N in plant tissue looks like it is between 2-4% which is 20,000 ppm to 40,000 ppm. Is the sap number lower? Will the 62-6200 meter work?
Thank you for your input. Where do you like to see N?
btw, the NO3 horiba meter on Amazon I'm looking at goes from 62ppm to 6200ppm. I see there are meters with different ranges. N in plant tissue looks like it is between 2-4% which is 20,000 ppm to 40,000 ppm. Is the sap number lower? Will the 62-6200 meter work?
