CEC and soil solution

Discussion in 'Growing Organic Marijuana' started by ElRanchoDeluxe, Jul 19, 2017.

  1. Waktoo and I had a brief discussion about this topic in another thread. I find it interesting. Here is a short read from Cornell. Wak, this is where I came up with soil solution decreasing with an increase in CEC, last paragraph. I figure everyone could benefit from this discussion and there is no need to keep it to PM'S.
    Certified Crop Advisor study resources (Northeast region)

    Please feel free to add any info on the topic or ask questions. Let's get a better understanding of this critical interaction that is rarely talked about.

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  2. That's really interesting RD! Thanks for sharing!
  3. So basically if my soil mix has a bunch on nutrients in it, that makes it harder for the plants to uptake? Only so many exchange sites and nutrients are getting locked out?

    How does Soil Food Web play into this, could I over come high CEC limitations by using microbial products like i.e. Compost tea, Mammoth P, or Recharge to unlock and make soil nutrients more available to plants at a faster rate?

    Since PH is a factor also, seems like PH adjusting waterings to a 6.2-6.5 range would also help?
  4. #4 Flexinmyderf, Jul 19, 2017
    Last edited: Jul 21, 2017
    I believe what the article is attempting to demonstrate is that when starting from a blank slate, a high CEC soil will have less available nutrients in the soil solution than one with a low CEC, while both soil samples retain the same TOTAL nutrition. Which makes sense, gotta charge the batteries right?

    EDIT : the soil solution WILL move downward over time, leading to leaching of nitrates, phosphorus, and other ions. so anything NOT retained in the battery will be lost(leave your phone on the charger for 2 days... does it charge over 100%? make sense?) so eventually, a comparatively LOW cec material will eventually have material washed away, "nutrition" that otherwise would have been stored. In bro science terms, soil solution is "use it now or its gone" where as CEC or AEC materials are battery banks.

    So, once our high CEC soil has absorbed all it can from the base solution, that's when the WEB kicks in to begin replacing the needed nutrients, with ones not needed at the moment, new inputs, more active minerals etc. Removing our positively charged ions comes down to chemistry at that point, add an acid and there is a mineral release, which is replaced with another charged particle, and drains the battery.

    When we top dress or feed tea or whatever... we are adding juice back to our battery, which the soil life will begin to cycle back through the soil solution, break it down into charged particles, and begin attaching the particles back onto CEC sites, charging our battery.
    In this way higher CEC would seem to function as more of a battery capacity. Higher CEC with constant input would be less likely to deplete in the same time( due to loss of minerals through leaching or off gassing) as a soil with low CEC.

    It's my opinion high CEC should be something we seek. While it may have some draw backs(harder to "fix" a soil imbalance), Having a high CEC would allow us more leniency of feeding, whether too much or too little. I'd say much more important from a hydro kid standpoint tho. This being said, vermiculite is used in remediation industry to absorb and retain all sorts of shit in the soil, and in some cases entrap material to remove contaminants.

    Now my question is this, How do anions relate to this? Is the AEC of a soil related to to its CEC? Is a higher AEC beneficial? Or would one limit the other?

    Sent from my iPhone using Grasscity Forum
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  5. ∆∆∆∆∆
    I like the battery analogy man. Nice post. I have more questions than answers too. Not much time to read either. 100 bales of peat moss just arrived...if my back doesn't survive this I'll have more time...lol.
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  6. Holy shit man, 100x bails?? Hope you have a concrete mixer to do all that for you lol
  7. #7 Flexinmyderf, Jul 21, 2017
    Last edited: Jul 21, 2017
    So I've been doing loads of research on the relationship between AEC and CEC, or at least attempting. From what I can decipher(and I apologize for not being able to cite all the sources, literally went through 100+ at work today trying to understand all of the jargon) it seems that AEC and CEC are strongly related, in the same manner that an acid is related to a base, but not quite. CEC is most of our plants...food?, and AEC is the rest, like nitrogen and phosphorus(what led me to a lot of this).
    One paper I found(simply a thesis) http://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=4692&context=etd
    was a solid start, mainly because an issue at work pointed me towards biochar as a micron sieve for nitrates. The thesis was an enjoyable read, and it pointed me towards the reaction of AEC material in various PH environments, which all seemed to show a lowering of AEC as PH of water increased(some much more than others).
    So I started looking into + and - charged ions as a whole to try and understand, I failed.
    More or less I learned some stuff about chemistry, which was neat, but I found this towards the end, which compressed almost all of the things I read into a tiny little piece I found to be the jist of it all(at least as far as I care about my gardens).
    Soil science|Digital Textbook Library
    and that website as a whole just blows my mind. im in love with it, tho im having issues searching... maybe im dumb...
    Boils down to this, biochar is most likely the best source of CEC and/AEC in a non iron/aluminum based clay soil(or so i understood). While CEC char seems to be easy to make(and most likely the commercial grade for gardeners), AEC char seems to involve a bit more effort, and control. Id think with knowing this we could make better char(assuming we know how to safely do it).
    Increasing overall AEC as well as CEC components in a "soil" mix would seem to assist in the overall concept of no-till, since itd make the plot less vulnerable to a lapse in "feeding", and retain any additional... nutrients?... the plants cant absorb prior to them washing down beyond the roots reach.
    anyways, thought id share my findings after a day at work

    Edit: Also, I edited my above post to show a mental lapse when sending it out....
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