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sand_mueller

Hot piles, little nitrogen

sand_mueller
10 years ago

So we've all heard that a proper hot manure compost pile needs lots of high N manure from horse, cow, rabbit, goat etc, preferably with urine soaked bedding. also that pig and human manures are cold. So how is it that the sewage sludge mixed with chipped bark I hauled got as hot as any horse manure pile I ever made? also large nursery piles of chipped bark with no manure heat like crazy. I thought these materials had hardly any nitrogen.

Comments (14)

  • toxcrusadr
    10 years ago

    I have never heard that human and pig manures are 'cold'. I would certainly expect them to heat up in a properly balanced pile.

    This post was edited by toxcrusadr on Thu, Feb 13, 14 at 17:20

  • Kimmsr
    10 years ago

    Coal piles, piles of wood chips, piles of vegetative waste will all produce enough heat to spontaneously start burning given all the right conditions. Rags soaked with oils used in finishing furniture will, in certain conditions, spontaneously combust.
    I'm not sure about today but when I was in school, and when my kids were, this was covered in 8th grade science.

  • pnbrown
    10 years ago

    The wood-chip piles get hot if they are large enough - it seems when scaled up far less "green" is required. Also, if we are talking about tree branches and brush going through a chipper, there is a lot of green from the bark and the sap.

  • toxcrusadr
    10 years ago

    Not to split hairs, but spontaneous combustion of materials like oil and gasoline is a strictly chemical process, not biological, so the nitrogen issue is irrelevant. But I think we're all in agreement about the basic premise of the thread.

  • glib
    10 years ago

    Yep, wood chips piles are rather green. Especially evergreens, there will be a lot of green material in there.

  • GWTaz
    10 years ago

    I just tested my compost (horse manure) piles for Nitrogen they were completely deficient. I thought organic manure compost is supposed to be high in nitrogen..Can anyone explain?

  • seysonn
    10 years ago

    High temperature composting results in escaping nitrogen. I think cool slow composting is better. JMO

  • GWTaz
    10 years ago

    I pile manure up to about 5x5' and turn with tractor every month or so (or when I think to do this). Thinking that is slow?

  • sand_mueller
    Original Author
    10 years ago

    Hot manure compost should be about 5x5 or larger they heat to 160 degrees killing most weed seeds, Turned after three weeks, they reheat to 130 degrees and then after three more weeks are ready for any horticultural application, including seed media. The N is not lost, but is now conserved in the bacteria which caused the heat. I did it this way for years until now when I can find no safe manures.

  • toxcrusadr
    10 years ago

    GWT, I think the N is probably bound up in organic matter and/or living microbes in an active pile, so it is not in solution and available for measurement.

    Also, depending on what test you are using, it may not be all that accurate - home test kits are notoriously bad.

  • woohooman San Diego CA zone 10a
    10 years ago

    "Rags soaked with oils used in finishing furniture will, in certain conditions, spontaneously combust. "

    Yep. Wen I was a much younger cabinet maker, the local fire dept had to come out and put the dumpster fire out at 2 in the morning may times. Sawdust and oil filled rags in an enclosed dumpster = prime spontaneous combustion.

    Back to the wood chips, I've had a couple piles of fresh chips dropped off in my driveway by tree trimmers and they would heat up quite nicely.

    Kevin

    This post was edited by woohooman on Thu, Feb 20, 14 at 17:50

  • Kimmsr
    10 years ago

    Freshly chipped wood, especially if it also contains green leaves, will heat up really quickly because of the moisture and nitrogen levels in those chips. Because that N is not free, not soluble, most tests do not show its presence.

  • GWTaz
    10 years ago

    so much to learn!

  • woohooman San Diego CA zone 10a
    10 years ago

    GwTaz: Not really. That's a new one on me as far as the N not being readable. But the basics of compost is not daunting at all.

    Just keep asking questions and the good folks on GW will usually have the answer.

    Kevin