Discussion in 'Organic Lawn Care' started by Tim Wilson, Apr 23, 2009.

  1. Tim Wilson

    Tim Wilson LawnSite Senior Member
    Messages: 795

    I thought the following may be useful to some, so as not to lose track; that compost should be stable without active components. (low to no measureable N, etc) and with original ingredients not being recognizable.

    Components of compost quality
    In mature high-quality compost:
    • Parent feedstock material should not be recognizable.
    • Structure includes medium- and fine-size particles and humus crumbs.
    • Moisture content should be 40 to 50%, dry enough that the compost doesn't ball up in your fist.
    • Smell should be earthy, like humus or forest soil (this is the actinomycete microbe population); no ammonia, sour, putrid or manure odors, which are byproducts of anaerobic microorganisms.
    • Temperature should be near that of the air temperature; the material shouldn't steam unless the ambient temperature is below freezing.
    If quick-germinating seeds like cress, radish or wheat sown in a sample grow well, the compost is mature and likely of good quality. You can also buy on- farm test kits and laboratory analysis services for compost.
    The carbon-to-nitrogen (C:N) ratio plays a crucial role in the availability of nitrogen from any organic material added to the soil. The higher the C:N ratio, the more the balance favors carbon, and the slower the release of the nitrogen will be.
    According to the NOP, the initial C:N ratio of a newly mixed compost pile should be between 25:1 and 40:1. Finished compost C:N ratios generally range from 14:1 to 22:1, depending on the feedstocks.
    If the C:N ratio is much above 30:1, then the microorganisms that use the carbon in the material as an energy source will also immobilize the nitrogen. The nitrogen will remain in the soil, unavailable for use by plants until later.

    Finished compost
    Finished compost is a dilute organic fertilizer with analyses in the range of
    1-1-1 to 2-1-2 (nitrogen-phosphorus-potassium). Values will vary according to the types of materials used and how they were composted.
    Like soil, compost can be lab-tested for major and minor elements (phosphorous, potassium, calcium, magnesium, zinc, boron, iron, manganese and copper), water content, pH, organic matter, total nitrogen, nitrate, ammonium, carbon-to-nitrogen ratio, soluble salts and extractable heavy metals. This information can be used to determine how much compost to apply for maximum plant growth and minimum nutrient loss.
    Some labs can also analyze the microbial makeup of your compost, but the value of such testing is more difficult to assess. To evaluate composts' effect on soil fertility, test soils several months after application (but not during the winter or under drought conditions).
    The pH of finished compost tends to be slightly alkaline. Compost usually does not raise field soil pH to undesirable levels, because the total amount of compost applied is small relative to the amount of soil in the field. In greenhouse applications, where the amount of compost as a percentage of the growing medium is much higher, you'll need to monitor the compost's pH more closely. The alkalinity of the media can be neutralized if necessary with an NOP-approved sulfur or acidifying compound.
  2. tadhussey

    tadhussey LawnSite Senior Member
    Messages: 294

    Good post Tim, I was just talking with someone today on optimal moisture content in compost!
  3. DeepGreenLawn

    DeepGreenLawn LawnSite Silver Member
    Messages: 2,372

    It must be the old synthetic side of me but I still don't understand how 2-1-2 will provide the needed N for Bermuda... I do know that those numbers don't mean anything, that the N is available and needs to be broken down by the microbes, so on and so on, but I guess until I see it in my own yard, I will have a very hard time believing it or truly understanding it...
  4. DeepGreenLawn

    DeepGreenLawn LawnSite Silver Member
    Messages: 2,372

    Nice post though and good timing... I liked the idea of just pouring in my high N products in my compost though but that does seem very synthetic minded as there REALLY isn't much difference... still pouring on the nutrients not mattering where they come from. Too much, or too fresh is still too much or too fresh and defeats the whole true healthy organic lawn system...
  5. Prolawnservice

    Prolawnservice LawnSite Senior Member
    Messages: 612

    While on the topic of compost, and since we all now know that "it does a soil good!" how about expanding on how and why, I think this would be the perfect thread.
  6. treegal1

    treegal1 LawnSite Gold Member
    Messages: 3,911

    I think of it as the carbon that makes the machine work, like a fuel.....with homes,and the works......
  7. ICT Bill

    ICT Bill LawnSite Platinum Member
    Messages: 4,115

    Like a good friend of mine (Kevin John Richardson) always says

    "Organic matter is the gas that makes the engine run"

    Tree you have a package coming, let me know what you think long term. Inoculate your seeds with it, it may be a very nice addition.
  8. Tim Wilson

    Tim Wilson LawnSite Senior Member
    Messages: 795

    Believe me, it has taken me a long time to come to this comprehension, that N is just a description for what can be measured and what is immediately available. There can be just as much N in compost with 2-1-2 as in fertilizer with 28-1-28, it is just sequestered and is released through microbial interaction. It would be an interesting study to cover some grass with compost and some with manure and observe the effects over a season.
  9. DeepGreenLawn

    DeepGreenLawn LawnSite Silver Member
    Messages: 2,372

    This would explain why the customer I put a little more fresh compost on last year had a full green healthy yard all year. The initial topdress burned the yard it was so fresh but what was immediately available would have been either used or leached in a short time correct? However, the yard is still the healthiest in the neighborhood and for Bermuda to be healthy it would require the N to stay that way... hence it obviously was getting it from somewhere...

    I guess that is the first sign I have seen... curious as to what it will do this year... I have to topdress the other side still and plan on using a more finished product than the original topdress so that will be fun to watch how it compares.
  10. Kiril

    Kiril LawnSite Fanatic
    Messages: 18,335

    It depends on the test, but generally speaking your "typical" N test will only cover what is freely available (i.e. not tied up in organic matter).

    Ayyy, that it would, and I think we both know how it would pan out too. It is the reason why I like to see a manure addition to a low N compost.

Share This Page