Did My Compost Get Hot Enough?
Question
November 23, 2013
Hello. I am a farmer in Albuquerque and have a composting dilemma. We have 3 large piles that are fairly large and of different ages. Our oldest one is probably 8 months old and I have been checking its temperature, watering and turning it regularly. The pile peaked at about 135 degrees in August, but now the temp is down to 50-60 degrees. I just recently turned it and it hasn’t changed. Is the cycle complete? Or should I just add more nitrogen-ic materials? Thank you for your help!
Answer(s)
Answer by JZ: If you are doing hot composting then a reasonable target temperature is 150F maintained for about 7-14 days, then turn it. If your pile initially did not reach that temp. then the issue may be one of carbon to nitrogen in your mix and / or adequate air flow. A mix of C:N may be 1:1 that is for every pound of brown you would add a pound of green material. The bottom of your (pile) operation should be 12″ of sticks, twigs, pine cone, corn stalks, cobs. This serves as an air intake medium also referred to as bulking. Additional bulking material should be added as the pile is built. The pile should be covered to reduce evaporation. If your pile has produced humus, then you could screen that out and recycle the un-decomposed material in another pile with the above C:N proportions as a simple guide. See our info. on composting in the desert under Composting in our website's main menu. Hope that this is helpful. Write back if you have further questions.
Answer by JE: The cycle is complete if you a can no longer distinguish what was put into the pile except maybe some very large pieces such as wood chips, corn cobs pine cones. If you feel it isn’t there yet then you may want to just turn it over making sure it isn’t too dry by watering. If that doesn’t kick start it then you might want to combine it with another pile.