Pedogenesis

Discussion in 'Organic Lawn Care' started by Smallaxe, Mar 23, 2011.

  1. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,080

    The O, A, and B horizons are nothing more than 'hydrosorting' of the different sized particles. Who knows what they were in composition b4 that...

    Is there a problem with forming a specific mixture of clay, sand, silt/OM? Most soil literature I've read says 45% + 45%+ 10%, respectively = the best soils, for most cultivated crops and landscapes...

    I hve to agree, that a huge granite boulder would be a problem... unless it is used by the rock crusher to make driveways... :)
     
  2. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    "Hydrosorting", as you are calling it, is a fluvial process. Soil can develop horizons without "hydrosorting".

    Work with your native soils whenever possible. I generally try to avoid "topsoil" unless absolutely necessary for leveling purposes. If you must use it, then it should be tilled into the native soil if you are adding significant amounts.
     
  3. quackgrass

    quackgrass LawnSite Senior Member
    Posts: 253

    Root growth contributes to an increase in SOM, especially with grasses. Not only that, they aid in incorporating OM deeper into the soil. Surface applied OM+fertilizer will increase your SOM more so than just applying OM.
     
  4. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    Don't be so quick to assume that by adding fertilizer you will get an increase in SOM or SOC.

    https://www.soils.org/publications/jeq/articles/36/6/1821
     
  5. quackgrass

    quackgrass LawnSite Senior Member
    Posts: 253

    First of all, I wasn't quick to assume - I picked this up by working on over 300 square miles of revegetation work on mined soils that lacked any SOM.

    Second of all I was talking about Fertilizer + surface applied OM increasing SOM more so than just applied OM.

    Lastly, You cited a study using synthetic N to a harvested crop, which has nothing to do with grasses which typically would not be harvested nor tilled.

    But thanks.
     
  6. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    You didn't read the study Quack.

    https://www.soils.org/publications/jeq/articles/36/6/1821

    The first decade of commercial fertilization brought a minor increase in soil C for previously unamended subplots, but this was followed by a decline despite dramatic escalation in the return of above- and belowground residues as corn populations were increased progressively to 69,000 plants ha−1 by 2003.

    Corn is a monocot .... just like a grass. If clippings are bagged, managed turf is being "harvested" just like a crop. If you core aerate you are in fact "tilling" to a limited extent.

    And if you weren't talking about synthetic N as your fertilizer input, what type of N or fertilizer were you talking about?

    And lastly ..... the findings in the study are absolutely applicable to any managed system with synthetic N inputs. Just because it is Ag doesn't mean the results of the study can't be reasonably extrapolated to other managed systems.
     
  7. Smallaxe

    Smallaxe LawnSite Fanatic
    Posts: 10,080

    That is one thing that I favor about Annual Ryegrass as a cover crop for weak soils... It will growlike crazy, both top and bottom... When it dies in the fall it is able to decay into the soil, making good conditions for next year crop of real grass...

    I agree, that using N to produce more biomass that stays onsite, should help with overall OM...
     
  8. quackgrass

    quackgrass LawnSite Senior Member
    Posts: 253

    Of course I wouldn't read a study about corn farming to determine SOM correlations to turf management. There is no reason to extrapolate because there are plenty of studies dealing directly with the issue, the only problem is that they prove you dead wrong - and that's why you chose to pick your study. You're a real credit to science Lord Kiril, nice work!
     
  9. quackgrass

    quackgrass LawnSite Senior Member
    Posts: 253

    But do you agree that a turf field resembles a cornfield? I often can't tell which is which because they are so similar! The bare and tilled soil between rows and plants is so hard to distinguish, in fact I can't even tell the difference between corn and turf if its sitting on a plate, they are just too similar! People ask me if they are managed differently and I say no, they're both moocots. :laugh:
     
  10. Kiril

    Kiril LawnSite Fanatic
    Posts: 18,308

    WOW! How does one respond to that level of ignorance? Answer ... you don't .... just let the person live in ignorance because that is where they are comfortable being.
     

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