Organic? Really?

Discussion in 'Organic Lawn Care' started by ChuckNC, Apr 6, 2011.

  1. Leo the Landscaper

    Leo the Landscaper LawnSite Member
    Messages: 116

    P might be everywhere but it is not everywhere in the same amount and in the same form of availability.

    The issue with P is mobility and availability. P provided via organic fert to a perennial crop like a lawn is very difficult. P has low solubility so it does not move readily through the soil profile. That is why P pollution of surface water is such an issue. P really needs to be incorporated to the soil. So I would say synthetic P is safer for a perennial crop than organic P, but even P in synthetic fert is not that solubility

    Mycorrhizae benefits plants by extending the surface area of the soil that the root can mine nutrients this is beneficial for the uptake of immobile nutrients like P. Plants must give up space and Carbon in this relationship in turn for the benefits provided by the Mycorrhizae. If one fertilizes to the point of providing enough P to the plant, the plant does not need this association and therefore there is no benefit in expending Carbon to develop the mycorrhizae relationship. Thus the plant will lose out on the other benefits of the relationship like increase in available water, inhibition of heavy metal uptake, etc.

    So P does not directly damage the fungus it prohibits the forming of the relationship by providing the needs to the plant without them.

    P is one of the main issue with organic fert. Plants take up 5-25% as much P as N. Manures contain about 25-50% as much P as N. So to fert with manure based fertilizers based on a soil test N. You will be over applying P, which has negative environmental impact. Remember P does not move through the soil so it is lost via surface water. Surface water makes its way in my part of the country either to The Great Lakes or the Gulf of Mexico. Unlike soil, whose most limiting nutrient is N waters most limiting nutrient is P. So when you add P you see a dramatic impact. It causes eutrophication, which is accelerated growth of algae. This mass algae bloom then dies and decomposes causing hypoxia, as the O2 is consumed by the decomposers. So to say that organic manures are safe alternative because they are natural is incorrect. They need to be carefully applied and managed as synthetic fert. I would argue that in a perennial crop like turf synthetic fert might be more environmentally friendly when used by those than don't fully understand these concepts.

    One more thing to remember about organic fertilizers like manure. Their source of N is from an animal, whose source of N was agricultural crop whose source of N was a synthetic fert.

    I am not anti organic, but we cant demonize synthetic fert because it is still a necessary tool.

    Sorry for ranting.:usflag:
  2. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    So you are answering the question about increasing the population, health and vigor of AM Fungi as, "Be sure no P is added to the soil..."
    Is that correct, and there is nothing more to do as far as you know?

    Your second subject about waterways recieving P runoff from manure is strictly manure... If the manure itself ends up in the water, then yes, it is as bad as leaves, decaying in the water...
    But to say that P goes into the water short of an erosion event, is untrue... N is water soluable and will dissolve and follow a "Stream" to the lowest point of a lawn, But P, once bound to a site. stays on that site... :)
  3. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    I was waiting all along for you to say something in an answer to the question and some real discussion but you seem to have leaked out as well... So you ARE a wiseguy, aren't you... :)
  4. starry night

    starry night LawnSite Gold Member
    Messages: 3,228

    So you are implying that soil biology then processes this manure in the same way that it processes synthetic fertilizers? Or, otherwise, what is your point?
  5. OrganicsMaine

    OrganicsMaine LawnSite Senior Member
    Messages: 553

    From what I gleaned from Leo's post is that he is still looking at the organic approach as he does a synthetic approach. If we were applying manure or even various composts in place of a synthetic fert, then he is correct in many ways.

    However, if we are using a manure/compost to boost the organic matter of a given soil profile, and then using some form of CT or ACT or AACT or Extract...or whatever, this is where the organic approach is more environmentally friendly. By building the microbes/fungi etc., and providing them with enough food, we are dramatically reducing the need for the fertilizer "programs" that we are all so addicted to. Paradigm shift, but doable in my opinion!
  6. Tim Wilson

    Tim Wilson LawnSite Senior Member
    Messages: 795

    To quote Barry 'Bingo!!!' Leo: Manure is NOT compost.
  7. JDUtah

    JDUtah LawnSite Silver Member
    from UT
    Messages: 2,636

    Ironically Manure has much better (more concentrated) green grass nutrients (nitrogen) than compost. If applying based on N needs, manure is MUCH more favorable to AMF than compost.
  8. Smallaxe

    Smallaxe LawnSite Fanatic
    Messages: 10,082

    The gardeners out here in rural America still use green manure tea, for fertilizer... Works great for gardens but not aesthetically acceptible for lawns... besides, you would have to print warnings about not eating the grass or rolling around in the lawn for 2 months... :)
  9. Leo the Landscaper

    Leo the Landscaper LawnSite Member
    Messages: 116

    You should add P based on a soil test. I am simply explaining the concept behind why P is "bad" for mycorrhizae.

    What I am saying is P moves with surface water because it is not soluable. N moves down into ground water due to its solubility. Due to P's poor solubility surface applications have a tendency to move offsite with surface water. If P is incoprorated than yes once it binds with Ca or Fe it tends not to move. N typically pollutes ground water P typically polutes surface water.
  10. Leo the Landscaper

    Leo the Landscaper LawnSite Member
    Messages: 116

    I dont think I said manure was compost

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