The point of this article is not that you don't have to turn your compost pile . . . you never did! The point I am trying to make is that you can achieve hotter, weed killing temperatures, sustained for a much longer period of time . . .without turning!
Read how . . .
I am currently doing research on the effects of insulating the compost pile, and not just to maintain higher temps in cold weather. When I first started this spring, I covered a small pile of (wood shaving based) horse manure with a giant sheet of bubble wrap. I was anticipating that I was going to starve my pile of the oxygen that I have always been told it would need. What I discovered instead was that because of the course texture of the shavings(that prevented matting), there was enough oxygen dispersed innitially to maintain high temps for almost three months with no turning. What I hadn't thought of (but was a huge bonus) was that the plastic insulation prevented the moisture from being evaporated out by the heat. My pile stayed moist all the way to the end. The other huge benefit to doing this is that you get high temperatures all the way to the surface of the pile . . . no cold spots! The temps immediately under the surface of the bubble wrap stay a toasty 140 degrees and are even higher deeper into the pile. This means that a properly insulated pile of the proper moisture, C, & N content does not need to be turned . . . will be finished in around ninety days . . . and is capable of killing all weed seeds contained in the material (not just those in the center). Again, I believe the courseness of a substantial portion of the material plays a big role by preventing the anerobic conditions that matting encourages. What this means is that when properly constructed and insulated, no turning is needed, no watering is needed, all seeds are killed, and fast results are achieved . . . or at least that is my experience so far. I am hoping many others will try this and share their results too.
I am also experimenting with pulling out the material while the pile is still opperating at high temps, letting it cool, and using it to mulch. I am finding that the "burning" potential of the manure is removed from the material, long before the pile begins to cool down. This means that you could utilize your compost sooner than you would if you waited for the pile to cool. I believe that this is because the insulation helps create a more ideal environment for the heat producing bacteria, therefore they produce heat further into the process than they would in a conventional pile.
Lets say that a conventional pile is kept moist and turned every few days and begins to go cold after four weeks. Then lets say that beside it is an insulated pile that stays moist, is not turned, and after four weeks it is still very hot. Does that mean that the material in the first pile (conventional) has broken down more? I don't believe that is the case. I think it goes cold faster only because it isn't as ideal an environment for the bacteria . . .but the material in the second pile that is still hot has nonetheless broken down further already . . . even though it is still hot! It appears that a materials ability to "burn" your plants is NOT directly related to how hot it is when pulled from the pile.
I am hoping others will assist in this research as well.
BTW . . . my current insulated pile is being used (effectively) to heat the water in our home! I am not really stealing much of the heat (cooling down my pile), because the insulation captures so much of the heat that would normally be lost. Just keep the water tank near the top of the pile but under the insulation. On top of that, the insulation helps to maintain a more ideal environment by retaining the moisture as well . . . not preventing it by starving it for oxygen as I had anticipated. Adding fresh material can help add a little O2 for a little boost . . . but I have found that even untouched, the temps stay high for a much longer time than in my uncovered piles of the past. I keep my insulated pile open to the ground below for some exchanges to take place and hadn't planned to try insulating that as well . . .perhaps someone else may. If your material has the courseness and roughage, you should be able to add bonus oxygen through the addition of fluids where any excess would drain through the bottom.I don't know if urine holds much oxygen, but that has always been my favorite liquid to add to a compost pile since the leaves, paper, wood shavings, and other "browns" keep my need for "N" high.
Note: I have noticed that the "leaks" in my insulation play a major role in allowing some oxygen to enter the pile. This shows how important finding the right balance is for each unique situation . . . insulation and trapping moisture are very good, but completely sealing off the pile would have an adverse effect and slow things down far more than not covering at all. Click here to see a test between an insulated pile and a conventional pile.
Also see my Insulation test ! ! !
