another soil test question

Discussion in 'Organic Lawn Care' started by roccon31, Jul 16, 2009.

  1. growingdeeprootsorganicly

    growingdeeprootsorganicly LawnSite Senior Member
    Messages: 766

    riggle is right on, it's a rye. over seed with quality seed, keep lawn properly cut/watered

    and in the fall 1/2 inch topdress don't double 1/4 inch it so to speak.

    add some sul-po-mag and or calcitic lime/gypsum perhaps too?

    a pic of the yard and a large soil core might get you more answers?
  2. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    That CEC is anything but high. You do need to increase OM% and your pH is right on the edge of acceptable. Probably wouldn't hurt to put down some lime. Stay away from the P for 2-3 years at least.
  3. roccon31

    roccon31 LawnSite Member
    Messages: 119

    thaks everyone. the grass looked like rye to me also, but i couldnt nail it down. we are definately doing some better seed in the fall along with the topdressings. they want a dark green "soccer field" type of look, so im thinkin im going to try some athletic field (80 tttf/20 PR) seed this time or a straight tri-tall fescue blend.

    this lawn has had a lime app since the soil test, so that should be a little better. will get more lime at topdressing time.

    kiril- i thought a good cec was 12-15? at least that is whats in my nofa notes.....not that it is high, but MUCH higher than i expected.

    by the way, this soil is very hard red clay, typical of this area. was thinking of adding 25% sand to the topdressing mix, for sh^*s and giggles. maybe it will help the drainage of the soil?
  4. growingdeeprootsorganicly

    growingdeeprootsorganicly LawnSite Senior Member
    Messages: 766

    roc, kiril posted some good links on CEC recently, talks in detail about different clays and their CEC. some clays have good CEC some not so much, research your area'a soil type's to get a better idea what ur working with and what works best to fix issues.

    for ur renovation skip the sand i would suggest, depending on ur compost source you will have some sand anyway, you need OM!!
  5. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    For best results and quickest adaptation mix in the sand with the compost rather than w/out the compost. After a good core aeration, of course.
    Remember CEC is in the clay as well as the OM so it may read high in the lab. But on a compacted clay field - I wouldn't bet on it.
  6. muddstopper

    muddstopper LawnSite Silver Member
    Messages: 2,341

    One thing that everybody overlooked is the actual soil test results. At least none of the recommendations they shared had anything to do with the soil test report.
    Test results show you need 63lb of caco3 but it didn’t say what the best form would be to use. Considering your Ca saturation of 38% and Mg sat of 12%, one would think that calcitic lime would be the best choice for your CaCo3. Not so. In your case, dolomite would be the better choice. The simple addition of calcitic lime will lower your already adequate Mg saturation levels, therefore the use of a lime that contains both Ca and Mg will raise Ca levels while maintaining your Mg levels. This then poses another problem, raising your Ca-Mg saturation levels will also lower your K saturation levels, which are also already low, hence the soil test recommendation of 2.9lbs perMsqft. Another non factor was also pointed out as a possible problem, your 164ppm of P. While this might be considered somewhat high, whenever you apply the dolomitic lime you will see a tieup of P in the soil because of the cation/anion attraction. At most the only problems you might encounter because of the high P is tieup of some of the micronutrients such as Zinc and Copper, which wasn’t tested for on your soiltest report. I also disagree with someones statement about the tons of Al in your soil, there is no evidence posted that would suggest that you have high or low Al, this is just an assumption on someones part.

    Your suggestion of a double aeration and application of a good quality compost, along with the overseeding and lime application, will go a long way to improving this lawn. Your concerns about high CEC and low OM content is nothing to worry about. CEC is the ability of the soil to exchange nutrients, 12 is good. While organic matter will effect CEC, Om is not the only factor to influence CEC . While problems usually don’t start until OM levels get over 7%, Soils with to high a OM content usually arenot anymore fertile than a low OM content soil and can actually hold on to nutrients instead of letting them become available to the plants.
  7. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    That is a recommendation Mudd, not a test result. Furthermore Ca & Mg are nearly identical with respect to preference on the exchanger. To state that Mg will go down because Ca is going up is one mega leap, especially considering the potential relative percentages of each (i.e. chemical makeup of dolomite).

    This is definitely possible, yet does not mean it will leach out of the effective root zone, only that it may be displaced deeper into the profile.

    Given the pH, this is not likely to happen. Even if it does, it becomes part of the active or labile P pool.

    Once again, given the pH is this even worth considering? Now if the pH was around 7.00 or above, then I might be concerned.

    Wondered the same thing.

    Whoa, back the truck up buddy.

    First, the measure of a soils fertility is more than just CEC.

    Second, please explain your thinking with specific examples of a limiting SOM% (with a mineral soil type) and a related drop in "fertility" and/or drop in plant available nutrients, and at what pH this might occur at.
  8. growingdeeprootsorganicly

    growingdeeprootsorganicly LawnSite Senior Member
    Messages: 766

  9. muddstopper

    muddstopper LawnSite Silver Member
    Messages: 2,341

  10. ICT Bill

    ICT Bill LawnSite Platinum Member
    Messages: 4,115

    Nice exchange of cations, I mean ideas

    You bring up an interesting point, we have a franchise near chicago that was doing some testing. They decided to test different types of compost for green up and density on some property they have next door

    4 different kinds of compost, a couple were bagged and the other 2 local sources, were applied in 4 different thicknesses, 1/8 inch, 1/4 inch, etc

    They were applied last fall (2008) and they were looking for results in the spring as the soil warmed. they waited and waited this spring, in late May they declared

    No difference in any of the plots, you could not tell the difference from the turf right next to it that had nothing applied. They then declared, compost does not do a soil or turf good, it makes no difference

    They called us and basically said, everything you told us is wrong.

    I asked, what is the SOM on the soil test before applying. It was over 9% before adding organic matter

    The soil already had enough available OM
    Now if JD with his 0.7% OM had done the same thing there would have been quite a difference I would suspect


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