Guidelines
on Agricultural Reuse of Human Excreta
Properly
sanitized human excreta can be used as an effective fertilizer and soil
conditioner. The concept of using human excreta in agriculture is called
"closing the loop", and is a fundamental aspect of ecological
sanitation. By collecting the nutrients found in urine and faeces
through ecological sanitation and returning them to the environment
through agricultural use, an environmentally beneficial and holistic
cycle is created. Ecosan stresses the link between people, soil and food
production, and attempts to de-link sanitation from the water cycle.
Human
urine and faeces contain valuable nutrients including nitrogen,
phosphorus and potassium. Urine possesses the majority of nutrients, as
compared to faeces, containing approximately 80% of the nitrogen, 55% of
the phosphorus and 60% of the potassium found in human excreta and
available for reuse.
Although a
few diseases can be transmitted through unsanitized urine, it is a
relatively safe fertilizer product, especially when compared to
unsanitized faeces. Faeces do not always contain pathogens or parasites,
but pose a high risk if they are not sanitized properly.
The
EcoSanRes Programme, in collaboration with the Swedish University of
Agricultural Sciences (SLU), is developing guidelines for the
agricultural use of urine and faeces.
The guidelines aim to educate ecological sanitation users about
how to handle the urine and faeces in a safe and beneficial manner and
thus promote the use of human excreta in agriculture.
The use of
human excreta as a fertilizer is beneficial from environmental, economic
and social perspectives. Increasing crop yields through the use of
sanitized urine and faeces is cost effective (requiring only an
investment in the ecosan toilet and secondary treatment system), and
greater crop yields increase nutrition in the household and help to
alleviate poverty. In addition, use of human excreta in agriculture aids
in gender development, especially in households headed by women since
these are often the poorest, by creating a possible source of income and
improved nutrition.
The
guidelines are developed by gathering information from previously
conducted experiments and comparing human excreta (as a fertilizer) to
commercially produced chemical fertilizers. The guideline will be
adapted to various climates and crops.
Contact
Dr. Björn Vinnerås (
)
or Håkan Jönsson (
)
for more information |