Learning about composting inputs
Can you imagine building a compost pile 8 feet high? That’s what I built my first compost pile. My memory might be a bit vague on that. The work was done more than forty years ago. Not too many years later I had a bit more space and my pile was only five feet by ten feet and not so high. I tried to shift these piles at least monthly between the southern Michigan spring thaw and the freeze in early December. Now, my pile may be turned only once a year. Along the line, I learned that I needed to balance “greens” (nitrogen) and “browns” (carbon). The input guide was two bags of leaves to one of grass.
Learning a bit
Now in my seventh decade and after two back surgeries I balance the compost inputs differently. First comes the collection area where we dump dry material until rain comes. Green material goes into the first bin. I no longer brag that I can compost anything and only collect chopped or small stuff. Friends bring me coffee grounds from the nearby convenience store or the dining hall of the local educational institution so that I have a strong nitrogen component. The first bin is usually full by the end of the summer. Then I find a younger person, often from a youth/student fundraiser, to shift to the second bin where I add slotted drainpipe to help the microorganism keep air-healthy and working. Progress from first bin to finished compost in the third bin may take more than a year.
Balancing compost inputs
Earlier the major input was my labor. Exercise was good. Now the major input is time. I increase the nitrogen input if possible to reduce the need for more time and shifting. I cover the second pile either to hold moisture and/or avoid leaching of nutrients. So, I have six or so inputs that I vary depending on the circumstances: carbon, nitrogen, water, air, labor, and time. Probably should add space. If I had plenty of space and an abundance of organic matter, I would start a pile and continue to add to the end of it. When the beginning of the pile was mature, I would start harvesting.
Composting inputs, Part 2
Composting at a Community Center
Working with the local community center with required a difference balance of inputs. Donations of vegetables and fruit were unpredictable. One might describe the quality of much of the fruit and vegetables at near the peak of ripeness when donated. The kitchen folk found using all these donations was a severe resource and time management challenge. The result was often a lot of spoiled fruit and vegetables. For a number of years a hog farmer had picked up kitchen trimmings. Unfortunately he was not as regular in picking up the trimmings as summer heat or freezing weather required. Our small garden needed compost. I had an idea that if horticultural therapy worked, then why not composting therapy. My motto was “If life brings you garbage, make compost.” (or, if you’ve made the mess, it still works). I had little success getting that message across, but we still made good compost.
Since we had an abundance of high nitrogen material, we needed to find sources of carbon. At first, the city allowed us to get partially shredded leaves at their collection site. Then they contracted with the landfill to use the leaves as cover for methane generating trash site. We started contacting tree-trimming firms and they provided us with wood chips to mix with the spoiled fruit and vegetables. A local butcher shop asked us to help remove some of the manure from their holding pens which turned out to be mostly sawdust. This additional source provided us with a good balance of carbon and nitrogen.
Workday procedure changes balance
Our community center hosts unemployed and homeless people and people doing community service instead of jail time. Tuesdays are workdays, so some labor was available for the composting project. There were five bins. 1. A materials collection bin (mostly carbon materials). 2. Collection bin (kitchen trimmings, plus bakery waste from a local business). Bins 3 and 4 were “cooking bins” with pipes added for air. Bin 4 was mostly finished compost from which compost was moved to the sifting machine.
A fifth pallet bin was used to store sifted compost under cover for sale. Using woodchips for carbon and bulking required extra labor, but two friends designed and crafted a rotating drum compost sifter to speed this process. A fuel tank from a Volvo truck, was cut open with a half-inch screen added inside, Two windshield wiper motors turned the drum from Volvo trucks. A nearly exhausted Volvo truck battery drove the motors. Some of the compost was used on the garden. The drum rotated to sift out the wood chips and any stones and uncomposted clumps. Sifting the compost made it more appealing for sale. Usually, several pickup loads, plus bags of compost were sold at the yearly plant sale.
The labor input was expected to be high here with each workday helping to shift and sift compost. That didn’t happen. So, to get air into the piles, we started adding pipes with holes in them and using a rod to poke holes in the pile (poking down from the top) when new pile first started to cool. Sometimes the piles sat for several weeks, other times, service groups would come in and the labor input would be high—higher perhaps than the process of composting would warrant. Infrequently we covered the piles to conserve water and sometimes to prevent leaching of nutrients during heavy rains. On rare occasions we watered with city water while turning the piles.
The inputs were the same in the different situations, the balance very different. The inputs were: 1. Carbon (browns–like leaves); 2. Greens (like—grass clippings); 3. Air (pipes, poking holes with rod); 4. Water; 5. Time; 6. Labor. (Of course, we didn’t have the mechanical power that is usually substituted for labor in larger operations.)
Why do I compost (in piles)? Why not do “ultimate composting”—composting in place—on the garden? I have been told there is scientific evidence for the superiority of this approach. Most of my home garden and the community center’s garden are generally covered with leaves or chips. When we lack these, we use unsifted compost. But, at the community center we wanted to have compost to sell. Sifted compost looks much better. Two additional reasons for bin composting: One, I like to have compost available to set plants in when I plant them, sifted compost to cover seed with and for making potting soil. Two, I like to make compost, to see the transformation of organic matter. See my earlier blog “Composting and the Grace of God”.