case studies banner
home
principles
people
activities
case studies
books
links

 

incorporating compost
Using Human Manure ("nightsoil") in the Tai Lake Region of China
Overview China's farmers use human manure and urine, also known as "nightsoil", for fertilizer.
Scale field, subsistence farm, local region
Location Tai Lake Region, Jiangsu & Zhejiang Provinces, China (31N, 120E)
Elevation -2 to 10 meters
Climate Moderate Continental Forest, mild winters (Cfa - G.T. Trewartha)
Agricultural Region Intensive Subsistence Tillage, Rice Dominant - (E)
Population Density >100 persons / square kilometer
Principal Crops Rice (Oryza sativa), Wheat (Triticum aestivum), Rapeseed (Brassica napus), Mulberry (Morus alba), Soybean (Glycine max), Bok Choy (Brassica chinensis), Chinese Milk Vetch (Astragalus sinicus).
Domestic Animals Pigs, Goats, Chickens, Ducks, Geese, Domestic Carp (Ctenopharyngodon idella, others), Domestic Silkworm (Bombyx mori), Water Buffalo.
Soils Paddy soils based on alluvial loess (Entisols, Udifluvents)
Natural Vegetation Broadleaf Deciduous (D)
Ecoregion Humid Subtropical Province (H7)
Basic Principles addressed Use Renewable Resources, Conserve resources, Manage Ecological Relationships, Manage Whole Systems, Maximize Long-Term Benefits
Page Author and Date Erle Ellis

 

description

For thousands of years, China's farmers have used human manure, or "nightsoil", as fertilizer (King, 1911). In this example from the Tai Lake Region, nightsoil is collected and stored in large ceramic tanks or water-tight slate-lined or concrete pits. Manure and urine are collected in buckets within the household, or deposited directly in the storage tanks, which are usually located in the animal stall and toilet area of the household. Occasionally urine is collected and applied separately. It is common to mix pig manure with nightsoil in storage, as pig stalls are connected to storage tanks via a sluice, to facilitate collection of pig manure and urine. Prior to intensive use of synthetic fertilizers, nightsoil was an important fertilizer for nearly all crops, including rice and wheat. Now, nightsoil is applied mostly to small-scale vegetable plots and other rainfed household crops. The primary reason for this change is that nightsoil is applied in liquid form, so that it is much heavier than chemical fertilizers. As vegetables and rainfed crop fields are usually nearer to the household than paddy fields, nightsoil use is now concentrated in these areas. Another reason for preferential use of nightsoil on horticultural crops is that it is believed to enhance the productivity and flavor of these crops, especially Bok Choy. 

lessons learned

Nightsoil is a nutrient-rich fertilizer that sustains soil fertility and crop yields. By applying nightsoil over large areas of cropland, nutrients are recycled within the farm, without risking pollution of surface waters with nitrogen and phosphorus-rich wastes. The recycling of phosphorus in human wastes is especially important- humans are the top consumer in agroecosystems. Modern sewage management technologies cause the eventual loss of soil P to oceans and landfills. Now that populations have grown and nightsoil use has become more concentrated in rainfed crop areas, nightsoil applications may be increasing the flux of surplus nitrogen and phosphorus to surface waters, leading to eutrophication. There have always been health risks associated with nightsoil use (Richardson, 1950). One traditional adaptation to this risk is the near total avoidance of raw foods in China. Health risks have been further reduced by contemporary awareness of the spread of germs in human wastes, with farmers avoiding contact with nightsoil more now than in the past. Nightsoil is also allowed to ferment longer in the tank before application. As chemical fertilizers provide an inexpensive and convenient nutrient source, nightsoil use is on the wane, and flush toilets are becoming more common. If the trend toward nightsoil overapplication in small areas and sewage dumping continues, serious environmental damage is unavoidable, and dependence on external sources of phosphorus will increase. 

principles illustrated

Use Renewable Resources

Nightsoil is a renewable, on-farm resource.

Conserve Resources

Use of nightsoil conserves nutrients within the farm and household. It also helps in sustaining soil nutrient resources.

Manage Ecological Relationships

Nutrient cycling is increased by returning manures to soils.

Manage Whole Systems

Using human manure as a fertilizer resource also eliminates wastes.

Maximize Long-Term Benefits

Use of nightsoil builds soil fertility over the long term. 

 images


composting toilet

Please click here for more images

 

more information

King, F.H. 1911. Farmers of Forty Centuries, or Permanent Agriculture in China, Korea and Japan.Mrs. F. H. King, Madison, Wisconsin, USA.

Richardson, H.L. 1950. Farming in China. Agriculture, the Journal of the Ministry of Agriculture, Great Britain 56:585-589.

McGarry, M.G. 1976. The taboo resource, the use of human excreta in Chinese agriculture. Ecologist 6:537-541

Ellis, E.C., and S.M. Wang. 1997. Sustainable traditional agriculture in the Tai Lake Region of China. Agriculture Ecosystems & Environment 61:177-193.

Cheng, L.L., and Q.X. Wen. 1997. Transformation and managment of manure nitrogen. Pages 281-302 in: Z.L. Zhu, Q.X. Wen and J.R. Freney, editors. Nitrogen in Soils of China, Developments in Plant and Soil Sciences 74. Kluwer Academic Publishers, Dordrecht, The Netherlands.