THE THEORY AND PRACTICE OF MANURING

Muck is the mother of the mealbag.

—TRADITIONAL IRISH SAYING

AGREAT DEAL OF THE WORLD’S WISDOM is contained in manure. Not only the grain in the mealbag but the full-blown rose are, in one sense, the gift of turds.

To be accurate, manure isn’t just shit. It is both the dung and urine of an animal, the latter often contained in soaked straw or other bedding. It’s important to grasp this dual nature of muck, because while the solid feces are comparatively rich in phosphorus, they contain only about one third of the manure’s nitrogen and one fifth of its potash. The greater proportion of these two important nutrients is contained in the urine.

A whole web of organisms in the soil eats manure, cleaving the organic molecules into simpler ones, using some of the results to feed itself, pushing some back into the soil where something else munches it. Then the flatworms and the mites and the beetles and the springtails chase the fattened bacteria, fungi, and earthworms, devouring them, building their own cell walls, excreting the rest. At the death of insects, the chitin-digesting actinomycetes go to work on their exoskeletons, cleaving the tough shells into food and releasing that unmistakable odor that Pliny called “divine,” sweeter than any perfume and the only criterion by which to judge healthy soil.

Viewed from this perspective, the process of manure making is slightly comical, yet undeniably attractive in its variety and efficiency. From closer up, it is messy. The cow, horse, chicken, sheep, dog leaves its pie, manure, dung, droppings, dirt, to the tune of roughly two billion tons each year, enough for a three-foot layer over all the home gardens in America.

Who wants to pick it up? Less than a quarter of the manure (including both feces and urine) that these animals drop is usefully returned to the soil. Take the case of New York City. “Sanitation takes it away,” says P. O. Oliver of the New York City Mounted Unit. “It’s piled out back there,” says Bob of the Wichita Zoo. “We pay a guy to cart it off” says the owner of a horse stable not three city blocks away from a community garden that is starving for rich soil. And all over America, urban people wrap their dog’s doo fastidiously in old newspaper and chuck it in the trash.

If it’s any consolation, modernity and the flush toilet are not entirely to blame. Though among the colonists who destroyed New England’s already thin soils in less than a century were some few who had the sense to follow the first-century Roman writer Columella’s recommendations and return the manure to the cultivated soil—in some towns, William Cronon reports in Changes in the Land, there was a weekly lottery for the right to have the town sheep spend the night on one’s land—the majority let their stock roam free, diluting the benefit of their droppings over acres of pasture and forest.

I propose a new national symbol: not Smoky the Bear or an eagle but a colonist planting an apple tree over the old outhouse hole.