Human Wastes

Agricultural people in Asia, Central America, Africa, and elsewhere have used human excretion extensively. In rural China, every bit of night soil is collected and turned into fertilizer by fermenting it in pits or composting it. Contractors are paid for the privilege of collecting the night soil of the cities, which they in turn sell to the peasants; and privies along country roads are set up so that the traveller might benefit the famer with a bit of fertility. Most of these wastes are fermented anaerobically and the slurry is eventually applied to the crops by long-handled dip buckets after a heavy rain. In dry, arid climates, night soil is dried and pulverized and then mixed into compost for turning into humus.

In much of the Western world, such practices were not entirely unknown. The runoff wastes of barn and latrine were collected in large pits and utilized by the peasantry. They were spread as fertilizer with honey wagons and honey buckets onto fields and pastures in the late fall or early spring. American pioneers planted fruit trees over outhouse holes when these were full to supply nutrients to the growing tree. With the increased urbanization of the industrial age, disposal became ever more of a problem and the findings of L. Pasteur and R. Koch about the existence of pathogens in excrement (Anthrax bacilli, tuberculosis bacilli, salmonella, and viruses) led to the development of the sanitary flush toilet. Subsequently, the Western world flushes millions of tons of basic fertilizing nutrients into rivers and oceans, while relying increasingly on chemical fertilizers. King cites figures of 5,794,300 pounds of nitrogen, 775,600 pounds of phosphorus, and 1,825,000 pounds of potassium that are produced per annum per million population, which if not returned to the land are flushed into the ocean.

What about the utilization of human feces and urine in smaller gardens? Generally, gardeners have not had the need to utilize human excrement because of the availability of manures and organic substances. Biodynamic practitioners have avoided the use of human excretion, except within the circulation of matter of the closed, self-sustaining farm organism. Most organisms avoid their own excretions. Cows and horses, for example, will not eat the grass that sprouts lusciously around their own droppings; but cows will eat where horse droppings have fertilized and horses cherish the grass benefitted by cow dung. Between the excrement and the consumption of food, a number of conversions and natural cycles must intervene. In the wake of the First World War, when biodynamics was pioneered, fertilizer was expensive and raw sewage had been used on fields surrounding larger cities, such as Berlin, to close the fertilizer gap. The resultant vegetables, especially the cabbages, had an awful taste. It was then realized that human wastes cannot be used immediately as they are; if, however, they are fully composted, and perhaps passed through other organisms, then they are perfectly good sources of nutrients. Biodynamic farms that I visited in Switzerland collected barn runoff and latrine runoff in large cement containers. These containers are treated with the biodynamic preparations and stinging nettle cuttings to help them ferment in the right way. The stench of such anaerobic decomposition is avoided by floating a six-inch layer of shredded straw, peat moss, or sawdust. When they are full, the tanks are then left to ferment for two to four years while another tank serves for collecting. The fully fermented slurry is distributed over the pastures, where it completes its cycle by being used by soil organisms and plants. The plants are fed to cattle that close the biological cycle by producing milk.

For smaller gardens, the cycle must be different. The Findhorn garden made use of human wastes in its early stages by emptying the night buckets together with straw onto the compost heaps and letting it go through regular decomposition. This seems to have been satisfactory, though it is not such a long cycle. John Todd of the New Alchemy Institute reports of a longer cycle involving a number of organisms to purify sewage. A series of pools are set up through which the sewage circulates. Aquatic plants are grown in the first pool that are then fed to aquatic insect larvae, which feed fish; these are, in turn, fed to chickens, which, in turn, feed the humans again. The final runoff is used to irrigate tree crops and lawns.

Composting toilets, such as the Clivus System, the Van der Ryn System, or the Könemann closet are worth investigating. In any case, a thorough composting process and a long biological cycle must be made use of in order to get the best and most sanitary results. The composting can be done either aerobically, as when dried sludge is composted with other ingredients and goes through a good heating process, or anaerobically, as when digesters are used to produce methane that can be utilized to fulfill other energy needs and result in a fertilizer of sorts.