Soil Tests? Yay or Nay?

bigbadbiddy · Oct 1, 2018

Even if 3 labs use the same standardized Mehlich III test, you will get variance in results between the three labs.

The method I proposed is to ensure that the tests/labs themselves are not flawed.

If you go with only 1 lab and 1 analysis, you have to be 100% certain that it is accurate.

Imho you can't be 100% certain unless you make at least a second analysis from a second lab to back up/confirm the claims/results from the first lab.

Same with the PH meter example etc.

The point I was trying to make is that the alternative to soil analysis is to just do trial and error.

Now if you opt for a soil analysis, I maintain you need to go big, employ ideally several labs etc. etc. (all I mentioned before), because if you don't, you could end up chasing your own tail (as microbeman put it) and that might be even worse than trial and error.
And if you are willing to work with such uncertainty (are these values actually correct? are these amendment recommendations actually correct? etc.), I believe a soil test makes no sense, then you might as well go with trial and error.

Klompen · Oct 1, 2018

Microbeman said:
In my opinion, they should be using HPLC and ICP where applicable

I had no idea these guys did soil tests!

KIS · Oct 1, 2018

CannaRed said:
For a small timer, growing in a dozen or so 4 and 5 gals how do you recommend testing?
I want to test my ph
I know outdoors when getting samples you collect from several collection sites. Is this necessary in pots? In my pots where I have been topdressing layer after layer of organic matter- how deep in the pot should I go down?
What about (just as an example) lava rock. If I collect a sample that doesn't have lava rock does that skew ph results?

Well you can get your water tested for starters if you don't have municipal water, where they should be able to provide an annual report. And for the other question I would just mix the samples from all the pots together before sending in to the lab. We've been using Logan Labs, but there are others. The key is to stick with the same lab as others have mentioned and realize that it's just 1 piece of the total puzzle when it comes to plant health and growth.

bigbadbiddy · Oct 2, 2018

If you only wish to test your soil's PH, you likely won't have to go through a lab for that.

Most DIY and gardening supply stores here will do a basic PH soil analysis for free in their shops.

But just the PH, they don't do NPK etc.

Lost in a SOG · Oct 2, 2018

It takes 3 months for soil to fully settle down after you mix it up to cook, it's slightly pointless getting it checked earlier than that..

KIS · Oct 3, 2018

Lost in a SOG said:
It takes 3 months for soil to fully settle down after you mix it up to cook, it's slightly pointless getting it checked earlier than that..

If you're getting a test that is an acid extraction like the MIII test we've been discussing, I believe it will break down and account for most nutrients/minerals. Now something like a saturated paste test could vary I'm assuming as nutrients are cycled over the first few months but the MII, as I understand it, would be relatively consistent. (or as consistent as these tests can be, though pH may fluctuate over time).

h.h. · Oct 9, 2018

If I mix my own soil and I know what is in it, why would I need to test?
If I don't have a fertilizer program, why would I test?
Everybody has their own reasons.
I never found one.

Lost in a SOG · Oct 9, 2018

I think you would only test if you were brand new to organics and didnt have time to experiment, and maybe suspected already it was too hot?, or if something went really wrong and you had no idea how or why, like the pH tanking or something..

I thought about testing but then just thought bugger it the plants can be my testers..

The price isnt too bad though and if you just wanted some extra encouragement that your mix is good then it might be useful :dunno:

LadyGuru · Oct 9, 2018

h.h. said:
If I mix my own soil and I know what is in it, why would I need to test?
If I don't have a fertilizer program, why would I test?
Everybody has their own reasons.
I never found one.

Tell us the levels of boron in your soil then? Or how about base saturation of calcium? What about Si levels?

Or are you just saying you know the ingredients?

Microbeman · Oct 9, 2018

LadyGuru said:
Tell us the levels of boron in your soil then? Or how about base saturation of calcium? What about Si levels?

Or are you just saying you know the ingredients?

Can your lab tell you what form of boron you have? How this form of boron is taken up by the plant? If so then are you a candidate for boron toxicity? Why?

Measuring base saturation of calcium involves buying into a hypothetical. Some do some don't.

Similarly with silicon, testing involves knowledge of how it is used by the plant and in what form. If I garner a smidgen of this knowledge, I can find a way to make it available to my soil/crop.

LadyGuru · Oct 9, 2018

Microbeman said:
Can your lab tell you what form of boron you have? How this form of boron is taken up by the plant? If so then are you a candidate for boron toxicity? Why?

Measuring base saturation of calcium involves buying into a hypothetical. Some do some don't.

Similarly with silicon, testing involves knowledge of how it is used by the plant and in what form. If I garner a smidgen of this knowledge, I can find a way to make it available to my soil/crop.

I think you are familiar with the labs used by most on these boards, Logan and Spectrum. H3BO3 :tiphat:

I think the main thing to consider while balancing nutrients is to have them in abundance, and balanced. Then it's about bringing microbiology so the plant can pull what it wants.

Don't you adhere to late Albrecht and Tietjens? I would rather trust those two guys, than a soil recipe on ICmag where the inputs vary greatly. Just my opinion.

Mate Dave · Oct 9, 2018

You will need to test a marl if your expecting some returns. You'll need to balance the macro & micro's or you will find you suffer. Good native dirt is like 12-20% OM 60-70% Stoney & the rest is water. You can cook it in an oven to find this out. Further analysis is done in a lab to find the constituents of the PK the mobile ones are hard to judge... It's got a natural balance of NPK native dirt far richer then the best potting more readily available to cannabis making it not worth buying in Yards..

You are better testing the plant than the soil to see if the soil is clean or not..

What's the point in the soil test without a leaf tissue analysis any way? Did any of you study soil science? I know microbeman know's his stuff...

Microbeman · Oct 9, 2018

LadyGuru said:
I think you are familiar with the labs used by most on these boards, Logan and Spectrum. H3BO3

I think the main thing to consider while balancing nutrients is to have them in abundance, and balanced. Then it's about bringing microbiology so the plant can pull what it wants.

Don't you adhere to late Albrecht and Tietjens? I would rather trust those two guys, than a soil recipe on ICmag where the inputs vary greatly. Just my opinion.

I was not asking which labs but about their capacity. Spectrum seems to post up some good tidbits of knowledge. I've never spent less than $250 on a soil test that was reliable. (no real point made, just sayin)

We grew alfalfa in our fields for years which has a high boron demand and once I stopped getting tests from the local lab and depended on high organic matter I had better or at least equal results. Boron as well as other micro-nutrients are sequestered in organic matter (in the detritusphere) and so long as the microorganisms in the region have sufficient moisture and fuel then boron is transported to the rhizosphere. In natural farming it is moved into the roots via protein transporters.

What if I got a test and the results showed poor levels of H3BO3? I then apply some boric acid .... oops too much...yikes....I poisoned my crop. Accurate testing of boron is difficult you say? Gee, I wish I knew that before.

Don't you adhere to late Albrecht and Tietjens?

No more than I adhere to soil mixes on a forum.

Microbeman · Oct 9, 2018

What's the point in the soil test without a leaf tissue analysis any way?

Exactly.

MJPassion · Oct 9, 2018

h.h. said:
If I mix my own soil and I know what is in it, why would I need to test?
If I don't have a fertilizer program, why would I test?
Everybody has their own reasons.
I never found one.

To The Point:
If you are satisfied with your end product why would you test it for cannabinoids and all that other shit that gets you high?

Maybe some peeps want to know and that is all.

also..
Do you really know what's in your soil or do you only know what YOU have added to an unknown soil source?
Are you even using SOIL?

Microbeman · Oct 9, 2018

MJPassion said:
To The Point:
If you are satisfied with your end product why would you test it for cannabinoids and all that other shit that gets you high?

Maybe some peeps want to know and that is all.

If you want to know this stuff try to find a lab which tests for everything, soil, leaf tissue, compounds and alkaloids. (etc)

MJPassion · Oct 9, 2018

LadyGuru said:
Don't you adhere to late Albrecht and Tietjens? I would rather trust those two guys, than a soil recipe on ICmag where the inputs vary greatly. Just my opinion.

Microbeman said:
No more than I adhere to soil mixes on a forum.

Microbenam,
Considering your comment, I'm wondering what did you take away from those two, if any?

It sounds as if you disregard their studies completely.

LadyGuru · Oct 9, 2018

That was very surprising to me also. I have tried many soil mixes from the boards, and they all test horribly. Can only speak from my personal experience, as inputs vary greatly. I have some soil at the farm that is 5 years old now, made from a coots mix. The coots mix did very well, but after 5 years of dialing the soil in with tests from spectrum, I am now happier with my results.

I don't doubt Microbeman's results however. He also makes a great point about B toxicity.

Mate Dave · Oct 9, 2018

Coot & Stan are jokers.. Absolute jokers with soil.. Clowns even. My Tutor @ College has forgot more than they will ever have learned..

CannaRed · Oct 9, 2018

Mate Dave said:
Coot & Stan are jokers.. Absolute jokers with soil.. Clowns even. My Tutor @ College has forgot more than they will ever have learned..

Hey Dave,
Do you mind expanding on that?
More specifically: what are the faults of coots mix, and what is your mix?
Thanks so much, I'm here to learn

Soil Tests? Yay or Nay?

Active member

Active member

Active member

Active member

GrassSnakeGenetics

Active member

Active member

GrassSnakeGenetics

Member

The Logical Gardener

Member

Propagator

The Logical Gardener

The Logical Gardener

Observer

The Logical Gardener

Observer

Member

Propagator

Cannabinerd