Compost Piles

Discussion in 'Organic Lawn Care' started by Clapper&Company, Oct 30, 2007.

  1. 44DCNF

    44DCNF LawnSite Bronze Member
    Messages: 1,506

    I never did a lot of temp checking on my pile, but I don't think it would make it that high. I am still not convinced they combust because of heat from the composting process. Has this ever been proven in a lab condition? I haven't studied up on it but here are my thoughts. There could be so many causes and they can smolder so slowly it would be hard to say what caused ignition I would think. Think of it. All of the equipment used in blowing, gathering, transporting, shredding, or turning can emit a tiny spark from their exhausts (fire up one of your mowers at night and watch the sparks fly), a cig butt, a meteor fragment, lightning, static spark, fireplaces and firepits. A pile that is dry enough to ignite - could it get that hot since it is not cooking properly from being so dry? The dry outside could easily ignite but that is not where the heat is. I once put out a neighbors burning leaf and clipping pile two days after I watched them dump their grill ashes on it. This was not a real compost pile as they never tended to it, but just dumped stuff on it. It took that long for it to build up to a point that I could see and smell some small amount of smoke. As I turned it though it was more active underneath. As one of the links I put up above states, once past 155 or so, many of the bacteria will begin to die off and the temps drop until it balances back out and rebuilds. I would imagine a pile would max out around the 190-200 mark due to that self regulation, but then I am no expert.
    I do have good success with my pile though and always see substantial growth and color changes in whatever I add it too, be it topdressing the lawn before it comes to life in the spring or placing in with container plants or on the garden and beds. If I topdress turf in late winter, it revives nearly two weeks sooner than areas I do not get covered.

    I get bedding and manure from local stables maybe twice a year, and add my own clippings and leaves and appropriate kitchen scraps, ocassional water hyacinths and wood chips, deadheading scraps and fall clean up, weeds and sod trimmings, fire pit ashes, and soil from container plants at the end of the season. I've had piles ready in as little as two to three weeks, when I was able to turn them daily. The pile is too big now for daily hand turning so it's a slow cooker.
  2. Daner

    Daner LawnSite Bronze Member
    Messages: 1,307

    Moisture plays a Important factor on compost temperature...and also the material that's In the unfinished compost.
    IMO...The compost pile can reach a temperature that can ignite.
    Don't get me wrong on this, I'm not trying to say that composting Is unsafe...not at all...But I'm saying don't ever think a compost pile won't ignite and go to a flame, because It can under certain conditions

    As far as the lets call It a "flash point" ...Just before it catches fire...I think It would be above 300 degrees.
  3. ICT Bill

    ICT Bill LawnSite Platinum Member
    Messages: 4,115

    We aren't talking about backyard compost piles but bigger one typically found in commercial operations. They are normally in winrows 30 or 40 feet high and 100 yards long
    I don't think a 3'x3'x4' could catch on fire, I don't think it could get hot enough, not enough mass.

    Barns catch on fire all of the time because the hay inside is not dry enough, it begins to decompose and whoosh, no more barn.
  4. Daner

    Daner LawnSite Bronze Member
    Messages: 1,307

    I agree with you there Billy ...The smaller the compost bin the less heat It's going to generate ....But where does the risk of a compost fire start...I don't think you have to go 30-40 ft high in a pile to have the right prescription for a fire.

    Hay Is another thing...from experience when the moisture its up over 30% its getting hot.

    As far as the max temp that a compost pile can reach...I my self do not know the answer...But If It got hot enough to Ignite... the temp. Imo would be much higher than 180 degrees.
  5. cantoo

    cantoo LawnSite Silver Member
    Messages: 2,910

    I rooted up my compost pile today with my tractor. It's not very big this year only 4 loads of leaves and one load of grass so far. Last year was about 10 loads of leaves. Around 12' wide and 25' long. We use the material for jumps on our moto cross track and for growing pumpkins. Most of our leaves go to a farmers yard to mix with manure and spread on his fields. It's closer for us to dump at his farm, I can buy alot of topsoil for the fuel saved not driving home.
  6. ICT Bill

    ICT Bill LawnSite Platinum Member
    Messages: 4,115

    cantoo, Compost has many more nutrients in it than top soil. Good (aerated)finished compost is the preferred top dressing by me.
    I think you are letting go of a lot of good money not using it on peoples yards, try a comparison sometime. I believe you will like the compost results much more.
    It retains moisture better, has a much better biological profile (great for the soil), compost inputs stay with the soil for years, less turf fertilization needs, its free (well thats relative)
    Can you use too much, yes! especially if it is not a good finished compost

    If you can get the organic matter in the soil up to 3 to 5 %, even 7% you will be amazed at the results

    You do need to compost the right way, anaerobic composting will strip the compost of almost all nutrients especially N and can be detrimental to the soil and turf. If you smell ammonia the pile is going anaerobic, turn it quick and add something brown to slow it down
  7. Daner

    Daner LawnSite Bronze Member
    Messages: 1,307

    Up around this End of the world...the Govt. Gives us a grant on large compost containment projects...30% funded.

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