More Soil Test questions

Discussion in 'Organic Lawn Care' started by Keegan, Jul 2, 2008.

  1. Keegan

    Keegan LawnSite Senior Member
    from CT
    Posts: 606

    I received two results back today.

    First one all of the numbers are normal except magnesium. It's about double what it should be. Can that be reduced?

    Second, pH is perfect 6.7
    OM 16.7%
    CEC 32.2%
    % base saturation- perfect
    nitrogen 64 ppm
    phosphorus 69

    Should I just continue putting down the micro-organisms and no nutrients?

    the homeowner said it's been previosly treated with synthetics. I'm not so sure. He had the lawn totally re done with new top soil a few years ago. When I put the soil probe in, it went straight in. It looked like compost and it even smelled good.
  2. ICT Bill

    ICT Bill LawnSite Platinum Member
    Posts: 4,115

    Magnesium is very difficult to get rid of, it is something on my list to try to figure out.

    when you say "double" what exactly do you mean? double from what? Okay answer this what is the Ca to Mg ratio???

    Can you post a PDF of the results?
  3. treegal1

    treegal1 LawnSite Gold Member
    Posts: 3,911

    yes it is but you can lock it up. this is common with palms.
  4. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

  5. treegal1

    treegal1 LawnSite Gold Member
    Posts: 3,911

    Kiril, whats your take on carbon and CA to regulate the CA/MG ratio, or will this push the saturation out to far??
  6. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    Too many variables IMHO that determine selectivity to say for certain if it would work or not. Keep in mind, cations on the exchanger are, well exchangeable, and highly dependent on soil composition.

    The traditional way of dealing with high concentrations of a specific mineral is to displace and leach (ex. using gypsum to reclaim sodic soils).

    You might find this of interest.
  7. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,081

    The reference to char was good. TP had put together the correct ca/mg balance on everything I had read, but Kiril makes the point that - too many variables to say for sure.

    I would start adding char and test again next year. Char does take time.
  8. Prolawnservice

    Prolawnservice LawnSite Senior Member
    Posts: 612

    I've had good results lowering magnesium with gypsum, or sulfur if the pH is high as well, however it tends to leach out everything. Perhaps that would be where the char would help.
  9. Keegan

    Keegan LawnSite Senior Member
    from CT
    Posts: 606

    If you go by the % base saturation where Magnesium should be 10-15% and this test shows 30 thats double.

    I haven't figured out how to upload the pdf yet.

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