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blue_skink

Mineral content of green grass/green leaves

blue_skink
9 years ago

Sorry to be kind of dumb about these things, but here goes:

I understand that green grass (and maybe fresh green tree leaves, too) contain certain nutrients, including nitrogen.

So, if you leave them to dry and turn brown (before you apply them as mulch) what becomes of the nutrients? Do they somehow wither away? Thanks.

- Skink.

Comments (13)

  • User
    9 years ago

    Well I'm still am amateur at these things, but I believe as you leave the grass or leaves or what have you, you're allowing bacteria to breakdown the plant material and in turn the nutrients into something more bio available for other plants.
    Most nutrients are just cycled through the food web.

  • toxcrusadr
    9 years ago

    If you leave green grass spread out in the sun to dry, it does retain much of its N even though it turns brown. Leaves are a little different, when they fall they are already dry and brown and are lower in nitrogen and other nutrients than they were when they were green, because the tree re-absorbs them before it drops them. Green leaves, if dried, might act similar to grass clippings.

    Since greens don't keep well, unless you dry them, which is extra work, many composters who live in areas where there are a lot of leaves will do the opposite - collect fall leaves and store them till spring when there are more greens available to mix with them.

  • blue_skink
    Original Author
    9 years ago

    Many thanks to both of you for your answers. I have a pile of fresh grass from the mower which I placed into a barrow and now it's partly dried out & partly moldy of course. I wanted to place that matted mess on my beds for the winter.

  • Kimmsr
    9 years ago

    Fresh grass clippings will have a C:N ratio of around 10 to 20:1, but as those clippings dry they loose some of that Nitrogen as ammonia. You can smell it going out to the atmosphere. Some sources list dried grass clippings as having a C:N ratio of between 25 and 30 to 1.

  • blue_skink
    Original Author
    9 years ago

    I guess that is the bad news I needed to hear. Thanks, kimmsr. I did not know where to go to find that information.

  • toxcrusadr
    9 years ago

    You can certainly mulch beds with that over the winter. I often mix the last grass clippings with leaves (or mow them up together) and pile on the beds to cover them over the winter. In spring that can be raked off and put in the composter, or larger plants (tomatoes, etc.) can be planted through it so the bed is already mulched.

    As kimmsr said, in a pile, clippings will lose N as ammonia gas, but spread out on a bed, there is enough oxygen for good aerobic decomposition, so N will go down into the soil as nitrate, etc. as they decompose.

  • User
    9 years ago

    I'm still amazed at the quality of information on this site. Thanks posters.

  • Kimmsr
    9 years ago

    As I have observed many times even an inch of grass clippings piled on the soil as mulch will emit that distinctive Ammonia odor telling me that Nitrogen is gassing off to the atmosphere. A mix of 1 part grass clippings to 3 parts shredded leaves emitted an odor closer to that of good rich earth.

  • blue_skink
    Original Author
    9 years ago

    Well, aren't I in luck. I sent my boy to cut the grass where the fallen leaves are thickest. I'll have the coziest raised beds in all of North Amerika. Thanks to all of you who responded to my question.

  • subk3
    9 years ago

    The OP's original question: "So, if you leave them to dry and turn brown (before you apply them as mulch) what becomes of the nutrients? Do they somehow wither away?"

    Your question has already been answered, but I wanted to present it in a little different way. Dried grass is hay. the purpose of hay is as a way to preserve the nutrients in the grass so that those nutrients remain somewhat stable and palatable for animals. Properly dried (cured) and stored hay keeps the majority of its nutritional value for a least a couple of years.

    The control factor is moisture, and the art of producing quality hay is all about moisture management. Once moisture enters the hay/grass it is the catalyst that begins the process of breaking down/decomposition/composting.

    The answer to "what happens to the nutrients" is linked the moisture levels.

  • blue_skink
    Original Author
    9 years ago

    Thank you so much for your additional info and fine knowledge. I guess you are a livestock owner and it's your business to know these things.

  • toxcrusadr
    9 years ago

    Glad you got what you were looking for blue_skink. Does MB Cda = Manitoba? Are there blue skinks up there (besides yourself)? :-]

  • blue_skink
    Original Author
    9 years ago

    Thanks, Tox! Yes I live in Manitoba and there are skinks here, though I have not seen one yet even tho we live in an area with sandy soil and tall native grasses, too. They don't stay blue, they unfortunately outgrow that beautiful colour when they grow up.