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Lightweight Peat's Mucky Muck soil testing

biggreg

Member
Just looking at mg/kg numbers doesn't tell us anything about our element levels unless we convert with a bulk density. This isn't done with mineral soils that all weigh close to 1g/cm3. The mg/kg number on the test is equal to mg/L in mineral soils. In organic soils, it's all relative that bulk density.

Plants grow in a volume ( mg/L), not in a mass ( mg/kg)
 

biggreg

Member
biggreg, what do you do buddy soil testing?



No.my background is HVAC. I grow medically for a family member.

just got into this soil testing last march. It's been a frustrating road and I don't want anyone else to go through what i have scratching their heads, staying up late, even waking up with nightmares about soil tests. I'm angry that labs take our money without any clue as to what the hell they are doing. I'm just a regular idiot and I figured out they are full of BS. I've called about every damn lab in the country. I've raised hell with the NAPT. I'm fighting with them and sharing what I've found with our community to get growers and labs on the same page so we can advance our understanding of this little slice of gardening. If we are going to use these tests as a tool, let's use the right damn tool.
 

biggreg

Member
No one is really commenting on this thread.

Am i preaching what evryone but me already knew? Is this useful new info? Anyone else run into this yet? This is all stuff I wish someone would have told me last march.
 

acespicoli

Well-known member
You know I'm no expert, I just grow organic. I compost.... I have wondered the same things you do about soil compositions and minerals nutrients etc... I'm kinda ocd and my friends alla cc use me of speaking Chinese cause I go off on a tangent and I lose them with the details. I find your thread on here interesting.
 

acespicoli

Well-known member
So far I looked at this.

This is in accordance with Liebig's law of the minimum.[1] There are 14 essential plant nutrients. Carbon and oxygen are absorbed from the air, while other nutrients including water are typically obtained from the soil (exceptions include some parasitic or carnivorous plants). Plants must obtain the following mineral nutrients from the growing media:[2]
2
the primary macronutrients: nitrogen (N), phosphorus (P), potassium (K)
3
the three secondary macronutrients: calcium (Ca), sulfur (S), magnesium (Mg)
4
the micronutrients/trace minerals: boron (B), chlorine (Cl), manganese (Mn), iron (Fe), zinc (Zn), copper (Cu), molybdenum (Mo), nickel (Ni)
 

biggreg

Member
You know I'm no expert, I just grow organic. I compost.... I have wondered the same things you do about soil compositions and minerals nutrients etc... I'm kinda ocd and my friends alla cc use me of speaking Chinese cause I go off on a tangent and I lose them with the details. I find your thread on here interesting.



I've been growing with recycled container soil for 6 years. Always organic. I've had success guessing and I've had failures. I branched out into this world of testing to up my skills and have another tool in the box.

My poor wifey gets what your friends are going through. She has listened to hours of scoop related rants. :)
 

biggreg

Member
So far I looked at this.

This is in accordance with Liebig's law of the minimum.[1] There are 14 essential plant nutrients. Carbon and oxygen are absorbed from the air, while other nutrients including water are typically obtained from the soil (exceptions include some parasitic or carnivorous plants). Plants must obtain the following mineral nutrients from the growing media:[2]
2
the primary macronutrients: nitrogen (N), phosphorus (P), potassium (K)
3
the three secondary macronutrients: calcium (Ca), sulfur (S), magnesium (Mg)
4
the micronutrients/trace minerals: boron (B), chlorine (Cl), manganese (Mn), iron (Fe), zinc (Zn), copper (Cu), molybdenum (Mo), nickel (Ni)

Those are the elements that affect yield ( maybe a few more) Plants can uptake many more elements than those. Many other elements may not have effects on yield but are essential to human and animal health. Selenium, silicon, iodine just for starts. If plants don't uptake those in our food or our animals food, we get sick.

Organic soils are usually naturally low in micro and trace elements.
 

acespicoli

Well-known member
I get where your going, I have seen all different kinda soil compositions.
Sandy loam
Clay soils
Straight compost
Peat/humus
Etc

All of the weights are going to be different by volume
Then you come down to what does the plant have? Root volume?

How are nutes from the soil in organics or hydroponics absorbed ?
As far as I know it seemed like the need to be hcl or water soluble salts of the minerals?
That's why the volume to water soluble tests are valuable it gives us what is available to our plants where the roots can reach them?

I wonder what kinda volume the plants roots need?
Or outdoor soil here is in layers that look different.
So there are a lot of variables? Am I getting it?
 

biggreg

Member
Sandy soils have higher bulk densities
Loam's density is close the what the labs assume with a scoop
Anything over 20% organic matter is considered an organic soil ( vs mineral soil)
99% of labs test soil by weight.

Plants grow in a volume.

The nutrients in the soil solution have an electrical charge and stick like static cling to exchange sites on humus and clay. The higher the CEC, the more cling.
 

biggreg

Member
CEC means cation exchange?

Yep, cation exchange capacity. It's a measure of the number of exchange sites that the cation elements ( positive charged) can cling to. When elements are clinging to exchange sites, they are not in the soil solution until roots, microbes or fungi exchange some Hydrogen with the site.

The Mehlich 3 test was designed to extract what could potentially be available to plants, not everything in the soil. If a water soluble test can see what the plants have today, the stronger extracts like the Mehlich see what the plants may have tomorrow ( soil life dependent)

 

acespicoli

Well-known member
Since the electric charge on a proton is equal in magnitude to the charge on an electron, the net electric charge on an ion is equal to the number of protons in the ion minus the number of electrons.

An anion (−) (/ˈæn.aɪ.ən/ an-eye-ən), from the Greek word ἄνω (ánō), meaning "up",[9] is an ion with more electrons than protons, giving it a net negative charge (since electrons are negatively charged and protons are positively charged).[10]

A cation (+) (/ˈkæt.aɪ.ən/ kat-eye-ən), from the Greek word κατά (katá), meaning "down",[11] is an ion with fewer electrons than protons, giving it a positive charge
 

acespicoli

Well-known member
By the 1884 definition of Svante Arrhenius (Sweden), an acid is a material that can release a proton or hydrogen ion (H +). Hydrogen chloride in water solution ionizes and becomes hydrogen ions and chloride ions. If that is the case, a base, or alkali, is a material that can donate a hydroxide ion (OH-)


OK I think I'm catching up to you my chemistry is a little rusty!
 

biggreg

Member
I barely graduated high school in the Deep South. This stuff really made my brain hurt. Last lab class I had was back in '92 and please anyone correct me when I'm wrong, PH is potential hydrogen. Peat has a large portion of its exchange capacity filled with hydrogen. When we add Calcium or other Cations, we are filling the sites.
 

biggreg

Member
The Ph of the Mehlich solution is 2.5. So it's a strong acid.With some chelating agents to pull micros.

North Carolina has lots of organic, peaty soils and Dr. Mehlich developed this M3 test as his final work for the soils of his home state. The procedure was published right after he passed. He knew plants grow in a volume and pushed volumetric reporting. Mg/L and CEC reported in meq/100cm3 ( milliequevalents per 100cm3 )
 

acespicoli

Well-known member
I barely graduated high school in the Deep South. This stuff really made my brain hurt. Last lab class I had was back in '92 and please anyone correct me when I'm wrong, PH is potential hydrogen. Peat has a large portion of its exchange capacity filled with hydrogen. When we add Calcium or other Cations, we are filling the sites.

Sounds good to me, my last class was '90 lol it is right up there with rocket science!
Chemistry gets confusing that's why I wanted to make sure I knew the lingo and definitions, thanx buddy!

So what are you testing for it sounded like you worked some of the top tests on your own?
 

biggreg

Member
I just wanted to play with some mixes. I rather not guess and then react to defiencies. I read up on mineral balancing and suffiency levels and when I tried to apply it to my organic, peaty soil, the results were off. Took a 1/2 dozen tests before i suspected the labs were using a standard density. I sorta back engineered that they must be scooping before I even knew such a device existed. I felt like I uncovered a conspiracy. I knew the scooped reports were telling me my CEC was lower than it actually was.
 
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