By Donella Meadows
–May 16, 1991–
Suppose someone came along with a new invention that could 1) cut the nation’s garbage problem in half, 2) help clean up polluted waters, 3) reduce energy imports, 4) stop soil erosion, 5) increase farm profits, and yes, even 6) slow down global climate change. An invention like that should make its creator a billionaire and a candidate for the Nobel Prize. The only reason it hasn’t is that its creator is in fact the Creator.
The invention is compost. Black, ordinary, backyard compost. We need someone to jazz it up with patentable high-tech glitz, so we’ll start using it as enthusiastically as we should to solve a lot of problems we don’t need to have. Actually that’s beginning to happen.
Over 70 percent of household garbage is compostable, which means it’s organic — it comes from living things. That includes food wastes, yard wastes, and paper. You can add to it the sludge from sewage treatment plants, the manure from feedlots, the wastes from food processing, brewing, and sawmills, and tons of agricultural wastes, all of which make the compost better.
Only a small fraction of those materials are composted now. More commonly they fill landfills, leach into groundwater, are dumped into the ocean, or are burned into air pollution. None of those practices would be necessary, if we could come to see organic wastes not as waste, but as raw material for compost.
So I invite you to look a little more closely at what most of us instinctively look away from — the process of decay. A fallen leaf, a dead cornstalk, grass clippings, the scrapings from dinner plates are in fact packages of carefully assembled biochemicals. Nature doesn’t throw such precious material away. Instead nature’s recyclers — worms, mites, fungi, and especially bacteria — go to work transforming it into life again.
The recyclers break down big molecules into pieces small enough to be digestible, but large enough to conserve much of the energy and materials they contain. These pieces are absorbed as nutrients by plants and by the recyclers themselves, which multiply quickly when there’s work to be done. The manure on the cornfield or the garbage on the compost heap feeds a population surge of the recyclers needed to process it.
The recyclers turn the most indigestible part of the waste, plus their own dead bodies, into a chemically complex substance called humus or compost. It is dark, crumbly, odorless stuff, which holds water like a sponge, so it protects plants from drought. It is gluey enough to bind soil particles together and make them resistant to wind and water erosion. It is resistant to decay, and therefore it releases nutrients slowly — at just about the rate that plants can take them up, and not so fast that excess nutrients wash away to pollute lakes or streams.
For all those reasons, compost is a perfect fertilizer. Every gardener knows that. If the organic wastes of the cities could be composted back to farms, that would reduce farmers’ outlays for expensive fertilizers. It would improve soils, yields and profits. It would reduce our dependence on the fossil fuels used to make fertilizer.
And it would combat the greenhouse effect, by building up carbon in humus in the soil, rather than sending it into the sky as carbon dioxide from incinerators and fertilizer factories, or as methane escaping from dumps.
Composting can be done on any scale from backyards to cities. The pile next to my garden handles the kitchen garbage, yard wastes, wood ash, and animal manure of one farm. The 60,000 citizens of Witzenhausen, Germany, put their compostables into special green garbage cans (on wheels and with handles for easy transport to the curb) given to them by the city. Outside town there’s a simple shed and a front end loader to turn and aerate windrows of composting material. The end product nourishes the famous cherry orchards that surround the town.
In New Castle, Delaware, 250 tons of garbage and 230 tons of sewage sludge per day are composted into “Fairgrow,” which is used for athletic fields, cemeteries, golf courses, and landscaping. New Castle’s compost can’t be used for food crops yet, because one industry contaminates the sewage stream with nickel. The town has cracked down, and that practice will soon cease. Widespread composting will quickly force the separation of toxic wastes out of sewage and garbage systems and into hazardous waste treatment systems, where they belong.
In the U.S. the number of yard waste composting facilities jumped from 986 to 1400 last year. There are currently 13 municipal garbage or garbage/sludge composting facilities, with 10 more under construction, another 10 up for bids, and 72 in planning. Pick up an issue of Biocycle, the industry magazine, and you’ll see the ads for mechanized grinders, shakers, turners, and screeners. Composting is about to become big business.
The Creator is probably delighted that we’ve finally figured that one out.
Copyright Sustainability Institute 1991