Let us not kid ourselves, human beings are terribly wasteful creatures. Recent statistics show that the human race produces more than 12 times as much food as it requires as a species, and yet half of the people on this planet are living in poverty, many of them literally starving to death. I don’t propose a solution to the global mismanagement of food (because it is NOT a global food-shortage, it’s a regional food shortage because of first-world greed, but focus Robin, FOCUS!), what I do propose is that we attempt to reduce the amount of this waste entering landfills by sorting it before it leaves the home. Other recent statistics suggest that 99% of Sweden’s garbage is recycled; and I think it’s time we discuss compost and it’s relationship with home ownership and woodworking.
There are generally three types of compost, dissected by the nature at which decomposition occurs, that’s Aerobic (meaning “in the presence of air”), Anaerobic (meaning the opposite) and vermicompost (in the presence of bugs to assist in decomposition, rather than exclusively natural processes like bacteria and microscopic life). These three are performed cold, by that I mean it’s not an exothermic (self-heating) reaction. There is another type of compost that I’d like to highlight as a potential resource, and that’s hot composting, an exothermic reaction that can actually boil water. I will end on Hügelkultur, which has the most relevance for our waste as woodworkers.
This is what occurs when you introduce air to your system. Very common when you have a lot of plant material like leaves, grass cuttings, that breed bacteria to assist in it’s digestion. Rather labour-intensive, with the water content and internal temperature being critical to a healthy pile. This method can involve insects, making it a type of vermicompost, but not necessarily. This is the most common type for many gardeners, as you see them turning the piles with pitchforks and shovels, which also breaks up the clumps of waste, making it more easily broken down. The primary goal is getting enough air in the mix to promote the bacteria cultures to thrive and continue the decomposition process. Typically scent-free and relatively quick-working, though labour intensive.
Think of a landfill. Hard-packed material, no air and no turning/tumbling of the waste. Anaerobic bacteria are slow-growing, slow-moving and are less likely to break down the material in your lifetime. This works great on a civic-scale, but for home gardeners it’s not entirely reasonable a solution. The smells can be noxious, it can be difficult to deal with once digestion has occurred, and is generally unpleasant all-around. This is a natural process with the least intervention, but like many natural processes, has little worry about when you plant your daisies.
Many forms of compost can involve bugs, fungi and other critters to assist in digestion. It almost always has to be aerobic for anything other than bacteria to assist in the decomposition, but you can have aerobic without critters, too. This is a little more work than aerobic, because you have to make sure that your little helpers don’t drown, starve or cook in the various processes and conditions associated with the compost pile. Earthworms are typical helpers, though many others are effective, like forms of fungus and beetles. You have to be careful, though, that they don’t become a nuisance when you use the soil for your next gardening project.
We’ve learned that both micro-organisms and larger critters all contribute to the decomposition process. Be they Aerobic, Anaerobic or Vermicompost only really differs in the conditions that allow different types of critters to chow down. Hot compost is more of the same, but with a very distinct (and obvious?) difference. It’s hot.
By balancing the materials inside the pile properly, you can create a mixture that promotes an exothermic reaction, which is a wonderfully beneficial surprise, especially if you live in the great frozen north like I do. Proper design can allow you to build the whole pile in tiers, and lay down coils of pipe between the layers. This could then cause some pain when you dismantle the pile, but the longer you leave the pipes in place, the more perfect the compost pile will become. The contents will be finer, more completely broken down, and very, very clean. The byproduct could be a heated garage all winter, using the heat in the pile to warm water circulating through the hoses, into in-door radiators. This one is by bar the most attractive to me. The nitrogen balance can allow sawdust to be used in the piles, the ratio of carbon to nitrogen in the compost materials needs to be between 25 to 30 parts carbon to one-part nitrogen by weight to sustain the exothermic reaction.
Pioneered by permaculture scientists like Bill Mollison, this method is the closest to replication of nature that I’ve seen. It’s a little more intensive, and has more benefits than I can get into for a short (?) article, but I’ll try to summarize.
One method is described as: Stack trees along a contour line (areas of like-elevation) sort of like a dam or a fence. Then lay brush and leaves, clippings and so on among those trees. Lay sods, grass-side-down on top of those trees, and then cover the whole embankment in compost and plants. As the trees break down, in the presence of a catalyst Hügelkultur embankment by as much as 4-5 weeks before and after your natural growing season. By following the contours, you effectively create a water dam inside a ditch on the up-hill side, otherwise known as a swale, which keeps the hillside hydrated and virtually eliminates the need for watering. Sawdust from our shops can supply much of the needed nitrogen from this integrated system, or to the hot compost piles, but all of your cut-offs, odds and ends, split boards, the cleaner of your pallet boards, sawdust, old OSB or plywood paneling, anything can be used to make the Hügelkultur high-nitrogen bedding. What a great way to reclaim hilly land and recycle all that shop waste, rather than burning it and losing it all to smoke.
No reasoning one hobby can’t spawn several smaller ones? You could also provide your neighbors with all the “waste” as a valuable resource. Then they can give YOU tomatoes! It’s win-win!