THE ARTS AND SCIENCES OF COMPOSTING
The Rev. Dana Prom Smith, S.T.D., Ph.D. (1/30/06)
After a triple bypass and retirement Gretchen and I moved to Flagstaff, a new house and yard. When I shoveled the dirt, my heart sank. I felt the same way the Friday my drill instructor shredded my weekend pass when I was 17. Rather than a hot date, I policed a barren parade ground for cigarette butts. On maneuvers, I had suggested to Sgt. Staatz, an irascible, surly, sour, harsh, saturnine battle-tested SOB, that his infantry tactics were wrong based on my high school ROTC courses. Eventually, I become a Sgt/Maj, Special Troops, becoming in part that which I earlier despised, an experience both disquieting and humbling and, also, an experience not uncommon.
Sullen and surly, my yard was volcanic detritus dumped by the contractor on top of native clay. Patches of clay showed through the debris, like concrete patches in peeling linoleum floors. My yard had the cast of that barren parade ground. As Yogi Berra said, it was deja vu all over again.
Sharpies with toothpicks stuck in the corner of their mouths happened by selling dirt and rocks from a dump truck. I wasn’t inclined to buy either dirt or rocks. My soil was up to me.
I knew good soil. While studying for my doctorate at the University of Chicago, I served a country church amongst the corn, cattle, swine of Illinois. Sadly, at the time I was too busy with Plato and Saint Augustine to treasure black loam and peat bogs.
The forest floor behind our house is covered with slowly decomposing pine needles. After raking off the top layer, I mined the old bottom duff. Knowing the trees needed duff as much as I wanted it, I raked the top back.
For texture, I began mixing my soil using volcanic ash for lightness, clay for heft, and old pine needles for body. Sadly, I had no silt. By divine providence I encountered Hattie Braun, Chief Master Gardener, and Ellen Ryan, Flagstaff’s Head Composting Honcho. Their message: composting is essentially returning to the soil that which it has given us, making it rich. I bought two composting bins from the city. Eureka! Now, I began making my soil rich.
Key to the science of composting is the 3-1 ratio by volume of carbon to nitrogen. Charts about the 3-1 ratio in organic materials are easily available. Nitrogen, commonly called green, inspires microbuggies to work on complex carbon compounds, called brown, making them available as simpler nutrients for the plants. Precisely measuring the ratio of carbon to nitrogen is difficult with a shovel. Horse manure, kitchen scraps (no meat), brewery barley mash, clippings from the garden (no dog poop), dumpster diving treasures, buckets of coffee grounds, and the like, make measuring approximate. Science becomes an art with a palette of three senses, feeling, smelling, seeing. No tasting and hearing.
Tiny microbuggies mining the carbon deep in the compost pile work up a sweat, steaming the pile. Without nitrogen the microscopic critters will quit as the pile goes cold. Too much carbon without enough nitrogen "slow walks" the composting as the microbuggies loaf. Too much nitrogen which is volatile paradoxically causes a loss of nitrogen, resulting in smelly ammonia and buzzing flies.
Microbuggies need moisture, but beware of the dreaded extremes: wet and soggy. Wet will drown the microcritters. Nitrogen materials tend toward moisture while carbon materials tend toward dryness. Also, water is heavy, seeping down the pile, making soggy bottoms and dry tops. Turning the pile is a cure for soggy bottoms. If the pile is wet, it’ll sour and draw flies. Sour stinks with the sweet rank of putrefaction, not the rich aroma of decomposition. A good rule-of-thumb for measuring moisture is the feel of a washcloth firmly wrung out, moist but not wet. Usually, the organic stuff thrown in the composer will supply enough moisture, but if it’s dry, add a little water. If it’s wet, add some dry stuff like vintage horse manure.
The microbuggies mining deep in the compost pile need oxygen so the pile has to be turned now and then to get them fresh air. A pitch fork is best for stirring up an aerated whing-ding composting microbug-o-rama.
Good compost smells like newly turned earth in the spring, looks like dark loam, and feels like crumbles. As with martial arts, composting draws on nature’s energy rather than assaulting it with chemicals.
Raised beds rich with dark lustrous soil, producing bounties of vegetables and flowers, are composting’s rewards along with a sense of presence at the creation.
By the way, the generic scientific names for these microorganisms are aerobes, thermophiles, and bacteria.
Copyright © Dana Prom Smith