This is a great thread. I look forward to seeing where this goes.
Thanks Mr astera. For your time.
Thanks Mr astera. For your time.
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Balancing Soil Minerals
- Thread starter m_astera
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Thanks Michael. That was a really good explanation and cleared it up for me.
Unfortunately for you that just encourages me to ask more. Things that aren't listed as essential like Si, Mo, Co, Ni, etc. Do you do anything to adress these when you design soils? Is there ever a point with the really ultra trace stuff you just give up and foliar?
Unfortunately for you that just encourages me to ask more. Things that aren't listed as essential like Si, Mo, Co, Ni, etc. Do you do anything to adress these when you design soils? Is there ever a point with the really ultra trace stuff you just give up and foliar?
bamboogardner
Active member
Michael. On a soil that is 33% peat, 33% compost/EWC and 33% aeration, what is the best method to prepare the beds for next year if you have been religiously taking care of the microbiology all season with teas and other microbe additions like Tanio and AEA if the beds had companion crops of nitrogen fixing plants like vetch and clover through the summer which acted also as a mulch? And how would you add amendments after having a soil test done in the fall.
I was thinking to hand turn over the top of the soil just a few inches deep to allow the microbiology to work breaking down the companion crop, and at the same time, plant a cover crop for the winter. When the new cover crop is young, green and succulent, turn it over again and start over. Keep doing this until spring and then plant a final companion crop which will also act as a mulch with the canna clones that have been growing for 30 to 60 days before planting.
I just do not like the idea of disturbing the biology that has been working all summer with a rototiller to get the companion/cover crop in. And how many days before planting should the companion/cover crop be turned over so the microbes do not starve the canna since they are eating at the table first.
Is there a better way to add nitrogen and/or other nutrients to the soil in the fall/winter so that the soil is ready in the spring?
I was thinking to hand turn over the top of the soil just a few inches deep to allow the microbiology to work breaking down the companion crop, and at the same time, plant a cover crop for the winter. When the new cover crop is young, green and succulent, turn it over again and start over. Keep doing this until spring and then plant a final companion crop which will also act as a mulch with the canna clones that have been growing for 30 to 60 days before planting.
I just do not like the idea of disturbing the biology that has been working all summer with a rototiller to get the companion/cover crop in. And how many days before planting should the companion/cover crop be turned over so the microbes do not starve the canna since they are eating at the table first.
Is there a better way to add nitrogen and/or other nutrients to the soil in the fall/winter so that the soil is ready in the spring?
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bamboogardner
Active member
And for those who doubt the ability of Michael Astera to do a proper prescription on your soil, here are a few pics of his work. He did a prescription on two beds for me and it was the best money I have ever spent, period. The wife is 5' 10" tall for comparison.
ohhhhhh you're soilminerals dot com ohhhhhhh.
oh yes i've found your articles very interesting. just purchased the ebook! gotta catch up...
oh yes i've found your articles very interesting. just purchased the ebook! gotta catch up...
As a rule I rely on broad-spectrum micro-mineral sources like Azomite, rock phosphates, kelp, glacial rock dust, humate ores, anything that has accumulated a wide spectrum of minerals with a low level of potential toxics like Cadmium and Fluorine. Ocean fish bone meal and guano are also good micro-trace mineral sources.
Based on my reading, I don't think we really have a good handle on optimum levels of elements like Molybdenum, Cobalt, Nickel, or Selenium. Mo is reputed to give a great growth response in vegetables. In New Zealand in the 1960s it was recommended and applied extensively with some vegetable crop yields doubling. See Brown Trotter "Soil Minerals - the key to Farming Wealth and your own Health". It's a good read. The downside is that Mo is a toxic metal and it's doubtful that the amounts taken up by vegetables in the course of doubling the yield are healthy. Cobalt has also shown good growth responses, and I don't know of any toxicity problems from it, but I don't know enough yet to recommend adding say 5ppm Co.
So until I know more and have done more testing I count on the multi-mineral sources listed above.
great thread so far.... tagging in.
thanks for sharing MA
thanks for sharing MA
Calcium, Magnesium and Soil Texture
Apart from the effects that the Ca:Mg ratio has on soil fertility, the amount of Ca vs Mg in the soil has a profound effect on soil texture. Essentially, the higher the soil Calcium level the looser and more open the soil texture; the higher the Magnesium level the tighter the soil texture will be. A high Ca soil will be loose and airy, a high Mg soil will be tight and airless. If crop residue is plowed under in the fall, and by spring is not broken down but still appears green and fresh, chances are the soil lacks oxygen and air spaces, and rather than aerobic decomposition, anaerobic fermentation is taking place, producing alcohols and formaldehyde which act as preservatives. The most likely cause is too high a level of Mg, or even an inverted Ca:Mg ratio where Mg occupies a higher percentage of exchange sites than Ca.
Using the terms tight and loose soil to describe these phenomena is a bit deceptive, because what is actually happening is that Calcium is agglomerating or flocculating the clay particles in the soil. When the clay in the soil is clumped together in little islands and groups, this opens up air and water spaces in the soil. The opposite of a flocculated soil is a dispersed soil, where the clay particles are spread throughout the soil, plugging up airways and drainage channels. Dispersed clay particles are generally negatively charged, so they repel each other. Calcium and Magnesium have two positive charges, which gives them the ability to attach to two negative sites on two different clay particles, bringing and holding them together. The other base cations, Sodium and Potassium, have only a single + charge; they can attach (adsorb) to a single negative site but cannot hold two clay particles together.
So, if the ions Mg++ and Ca++ can both adsorb to two clay particles and bring them together, why does a high level of Ca lead to a loose, flocculated soil while high Mg leads to a tight soil? It's due to the relative size of the ions and their ability to attract water molecules. A water molecule is polar, meaning it has a partial negative charge on one end, and a partial positive charge on the other end. A free base cation in the soil/water solution will attract a thin layer of water molecules around itself, enough water molecules to equal out its own + charge or charges.
We can assume that Ca++ and Mg++ will attract an equal amount of water molecules because they have the same static charge. However, they are different sized atoms. Magnesium is atomic number 24, Calcium is atomic number 40. Atomic number is the number of protons in the atomic nucleus. Ca has 40 protons, Mg only 24, so Mg is a smaller atom; it has a smaller atomic radius. If each of them attract and bond with the same number of water molecules, the smaller Mg ion will be surrounded by a thicker layer of water than the Ca ion. Imagine spreading the same amount of cake frosting on two globes; the larger globe will obviously get a thinner layer of frosting (or water molecules).
For the purposes of this discussion it's enough to know that high-CEC clays (e.g. bentonite, montmorillonite) are layered clays. They tend to stack together because of unequal charges in their silica-alumina structure, with a number of negative charges unsatisfied between the layers. These - charges attract + charges, such as the cations listed above and also the free Hydrogen ion H+ as well as water molecules. The layers in a charged, layered clay become filled with cations, mostly Ca++, Mg++, K+, Na+, and H+. Water or lack of it in the soil has a strong effect on the ability of these clay layers to hold together. When the soil is saturated, large amounts of water molecules infiltrate the layers, moving them apart. This moves the + charged cations (our base cations) further from their attachment to the - charge on the clay layer, which in turn frees up some charge on the cations to attract water molecules, which shove the clay plates still further apart.
Above I mentioned the atomic radius of Ca and Mg. When cations are surrounded by enough water molecules to cancel out their + charge, they will of course have a larger radius, that of the atomic shell plus the water molecule layer. This is called the hydration radius or the hydrated radius. The hydrated and non-hydrated radius for our favorite cations is, in Angstrom units (0.0000000001 meters, or (0.00000000357 inches):
Element Non-hydrated Hydrated
Potassium K+ 2.66 7.6
Sodium Na+ 1.90 11.2
Calcium Ca++ 1.98 19.2
Magnesium Mg++ 1.30 21.6
Note that while non-hydrated Mg is 1/3 smaller than Ca, when hydrated it is ~10% larger than hydrated Ca. In practice what happens is, as the soil becomes saturated with water and clay interlayer Mg becomes fully hydrated, the water around the Mg ion pushes the clay plates apart so far that the attraction (between the clay layers) of the + charge from Mg no longer holds them together, the clay particles are dispersed, and the soil loses structure and air and drainage space. This is the case when Mg is excessive for a given soil. The Ca ion, on the other hand, even when fully hydrated, has enough electromagnetic attraction to keep the clay layers together, agglomerated, flocculated, preserving the layered structure of the clay and its ability to hold nutrient cations between layers.
Working with this is simple. If the soil is too loose, add more Mg to disperse the clay a bit. If it is too tight, add more Ca to flocculate the clay particles together.
For reasons I won't get into here, this simple knowledge has been ignored and even denigrated as useless and false by mainstream agronomy. On the other hand, it is well known to any student of soil engineering and is used constantly by oil well drillers to modify the texture of drilling mud.
I don't have a link, but a quick search for cals.arizona.edu/pubs/crops/az1414.ppt will bring up a short and well done ppt showing the principles discussed above.
Apart from the effects that the Ca:Mg ratio has on soil fertility, the amount of Ca vs Mg in the soil has a profound effect on soil texture. Essentially, the higher the soil Calcium level the looser and more open the soil texture; the higher the Magnesium level the tighter the soil texture will be. A high Ca soil will be loose and airy, a high Mg soil will be tight and airless. If crop residue is plowed under in the fall, and by spring is not broken down but still appears green and fresh, chances are the soil lacks oxygen and air spaces, and rather than aerobic decomposition, anaerobic fermentation is taking place, producing alcohols and formaldehyde which act as preservatives. The most likely cause is too high a level of Mg, or even an inverted Ca:Mg ratio where Mg occupies a higher percentage of exchange sites than Ca.
Using the terms tight and loose soil to describe these phenomena is a bit deceptive, because what is actually happening is that Calcium is agglomerating or flocculating the clay particles in the soil. When the clay in the soil is clumped together in little islands and groups, this opens up air and water spaces in the soil. The opposite of a flocculated soil is a dispersed soil, where the clay particles are spread throughout the soil, plugging up airways and drainage channels. Dispersed clay particles are generally negatively charged, so they repel each other. Calcium and Magnesium have two positive charges, which gives them the ability to attach to two negative sites on two different clay particles, bringing and holding them together. The other base cations, Sodium and Potassium, have only a single + charge; they can attach (adsorb) to a single negative site but cannot hold two clay particles together.
So, if the ions Mg++ and Ca++ can both adsorb to two clay particles and bring them together, why does a high level of Ca lead to a loose, flocculated soil while high Mg leads to a tight soil? It's due to the relative size of the ions and their ability to attract water molecules. A water molecule is polar, meaning it has a partial negative charge on one end, and a partial positive charge on the other end. A free base cation in the soil/water solution will attract a thin layer of water molecules around itself, enough water molecules to equal out its own + charge or charges.
We can assume that Ca++ and Mg++ will attract an equal amount of water molecules because they have the same static charge. However, they are different sized atoms. Magnesium is atomic number 24, Calcium is atomic number 40. Atomic number is the number of protons in the atomic nucleus. Ca has 40 protons, Mg only 24, so Mg is a smaller atom; it has a smaller atomic radius. If each of them attract and bond with the same number of water molecules, the smaller Mg ion will be surrounded by a thicker layer of water than the Ca ion. Imagine spreading the same amount of cake frosting on two globes; the larger globe will obviously get a thinner layer of frosting (or water molecules).
For the purposes of this discussion it's enough to know that high-CEC clays (e.g. bentonite, montmorillonite) are layered clays. They tend to stack together because of unequal charges in their silica-alumina structure, with a number of negative charges unsatisfied between the layers. These - charges attract + charges, such as the cations listed above and also the free Hydrogen ion H+ as well as water molecules. The layers in a charged, layered clay become filled with cations, mostly Ca++, Mg++, K+, Na+, and H+. Water or lack of it in the soil has a strong effect on the ability of these clay layers to hold together. When the soil is saturated, large amounts of water molecules infiltrate the layers, moving them apart. This moves the + charged cations (our base cations) further from their attachment to the - charge on the clay layer, which in turn frees up some charge on the cations to attract water molecules, which shove the clay plates still further apart.
Above I mentioned the atomic radius of Ca and Mg. When cations are surrounded by enough water molecules to cancel out their + charge, they will of course have a larger radius, that of the atomic shell plus the water molecule layer. This is called the hydration radius or the hydrated radius. The hydrated and non-hydrated radius for our favorite cations is, in Angstrom units (0.0000000001 meters, or (0.00000000357 inches):
Element Non-hydrated Hydrated
Potassium K+ 2.66 7.6
Sodium Na+ 1.90 11.2
Calcium Ca++ 1.98 19.2
Magnesium Mg++ 1.30 21.6
Note that while non-hydrated Mg is 1/3 smaller than Ca, when hydrated it is ~10% larger than hydrated Ca. In practice what happens is, as the soil becomes saturated with water and clay interlayer Mg becomes fully hydrated, the water around the Mg ion pushes the clay plates apart so far that the attraction (between the clay layers) of the + charge from Mg no longer holds them together, the clay particles are dispersed, and the soil loses structure and air and drainage space. This is the case when Mg is excessive for a given soil. The Ca ion, on the other hand, even when fully hydrated, has enough electromagnetic attraction to keep the clay layers together, agglomerated, flocculated, preserving the layered structure of the clay and its ability to hold nutrient cations between layers.
Working with this is simple. If the soil is too loose, add more Mg to disperse the clay a bit. If it is too tight, add more Ca to flocculate the clay particles together.
For reasons I won't get into here, this simple knowledge has been ignored and even denigrated as useless and false by mainstream agronomy. On the other hand, it is well known to any student of soil engineering and is used constantly by oil well drillers to modify the texture of drilling mud.
I don't have a link, but a quick search for cals.arizona.edu/pubs/crops/az1414.ppt will bring up a short and well done ppt showing the principles discussed above.
JACKBAYBEH
Active member
Subbed. Great read. Thanks M Astera!
That post is excellent. I love it a great concise explanation on the flocculation of the soil.
I do have a question. How does this affect a soil that has low clay percentages.
Timbuktu
I do have a question. How does this affect a soil that has low clay percentages.
Timbuktu
Taking the last question first, nitrogen is best added in the spring if growing outdoors. If added in the fall there is much greater chance of the N being leached away by winter precipitation as there is no plant life and little microbe activity to metabolize and use it.
I see no advantages to no-till unless the crop is a woody perennial, which cannabis is not. For perhaps 10,000 years farmers have tilled the soil for annual crops. When tillage doesn't happen the soil nutrients stratify; calcium leaches to lower horizons, beyond where the roots of an annual crop can reach. In the rainy Pacific NW, for instance, the high Ca soil layers are around 8 to 12 feet deep. Added phosphorus, being highly reactive and practically immobile in the soil, will remain in the top inch or less of the soil if it is not tilled in.
Tilling will not harm bacterial populations; if you have seen a pot of soup go bad you know how fast bacteria can multiply, and the action of tilling the soil, mixing up nutrients and incorporating more air, will quickly cause a population explosion of beneficial microbes.
While it is true that tilling can damage certain fungal mycelia, the question is what function are these permanent-type fungi performing? If their alleged function is to bring scarce phosphorus to crops growing in phosphorus-poor soils, that is not needed in a soil with abundant P reserves, which I believe would be the case for anyone successfully growing cannabis.
No-till agriculture of annual crops was developed and popularized by chemical farming promoters, with the idea that weeds would be killed with herbicides, saving the fuel that would otherwise be needed for plowing and weed control, and fertilizers would be water soluble so they could soak in and reach the root zone. Still they have the problem of stratification. I have yet to hear any convincing argument in favor of no-till for annual crops, especially for organic growers who are not using herbicides and soluble NPK fertilizers.
Thanks for your support, HB. I hope you get much good use from the book.
On that subject, those who purchased the earlier versions of The Ideal Soil (anything before v2.0 came out in early 2014) are welcome to a free PDF ebook copy of the new 2014 version. Just write to me at michael.astera@gmail.com and tell me when you bought the book or include the email receipt. Use the subject line "free ebook" or similar.
Mr A ( if I may call you that) I agree about the filling, it has a porpus in outdoor ag soils but do you still have the same problem in 16" deep pots?
I know I have a problem of to many roots in my pots sometimes.
Just wondering your thoughts.
Timbuktu
I know I have a problem of to many roots in my pots sometimes.
Just wondering your thoughts.
Timbuktu
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hobbyhorse
Member
Wow loving this thread. Thanks m_astera keep the ball rolling!
So do you see ammonium phosphate (ignoring organic cert concerns) being a valuable spring amendment? Or is it so reactive that it will become totally unavailable before the crop finishes? Does chelating it with fulvic acid make it less reactive and therefore available longer?
I would personally love to use it in cool spring soil to get my roots off to a faster start but have always feared the tie up problem
I would personally love to use it in cool spring soil to get my roots off to a faster start but have always feared the tie up problem
no till is easier on the back lol. that may be the major advantage indoors.
bamboogardner
Active member
Okay, if adding nitrogen in the spring is best for outdoors, how would you add it (type) and in what quantities.
I recommend higher Mg levels in sandy soils, based on the theory that will tend to tighten them up and hold moisture better, but have never done any experiments to prove it.
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