Night Soil & Gardening

Background

The name "night soil" originated in post-World War II China and Japan when waste---or human excrement---was disposed of at night time, according to the United Nations Environment Program. Urban area sewage systems consisted of collectors who hauled buckets of waste from homes to collection sites. These practices helped with sanitation needs but also provided a rich, alternative source of fertilizer for local crops. Modern-day gardening practices in China and Japan still utilize night soil as a nutrient source for flowers and plants.

Night soil gardening practices typically use the substance in powder, liquid and cake form, according to Gardenvisit.com. Countries such as China, London and France have even incorporated night soil products within their commercial activities. French companies market night soil under the name "poudrette" in a desiccated or powered form. In London, mixes that include charcoal or quicklime are sold as cakes and are also called desiccated night soil. In China, this human-sourced manure is mixed with fat marl and dried in the sun to form fertilizer patties.

As the food, water and nutrients that go into the human body originate from the environment or nature, night soil gardening practices work to recycle these materials back into the earth, according to Gardenvisit.com. This type of manure contains rich supplies of carbon, oxygen, azote and hydrogen and naturally decomposes when mixed into the soil. The use of quicklime and charcoal as mixing agents works to eliminate foul odors. When deposited along the ground in thin layers, these mixes can dry quickly, making it easy to blend with surrounding soil.

As environmentally friendly as night soil gardening may seem, there are some drawbacks to using raw human excrement as a nutrient source for flowers, plants and crops, according to Weblife.org. Raw excrement may be wrought with disease pathogens such as typhoid, hepatitis, cholera or intestinal parasites. In effect, the potential for food or soil contamination is high, as bacteria organisms appear in large numbers within human excrement. In addition, night soil applications that exclude a lime or charcoal mix can emit noxious odors over long periods of time and cover considerable distances.

Humanure is a less toxic form of night soil, made so through composting practices designed to kill off potentially dangerous pathogens, according to Weblife.org. Composting methods involve mixing night soil with kitchen refuse, yard waste or other sources of high-carbon materials. The mixture is then heated---either organically or mechanically---to kill off existing bacterial organisms. Organic heating occurs through the natural biological reactions that take place inside the mixture. Composting practices can also help eliminate foul odors.