Traditional night-soil composting continues to bring benefits
Night-soil (human waste) has been considered a valuable agricultural resource since ancient times. When handled safely, its use can contribute to reducing soil degradation and water scarcity in the areas like the Lahaul valley. Despite such known benefits its use is now decreasing with modernisation. Recognising this, the G.B. Pant Institute in India has been taking steps to promote the use of night-soil as one of the organic farming practices promoted in the region.
LEISA Magazine • 24.2 • June 2008
The Lahaul valley of the northwestern Indian Himalaya mountains is cut off from the rest of the world during winter due to heavy snowfall. The harsh and inhospitable climatic conditions prevailing in this region mean that farmers have developed unique agricultural management practices.
In recent years, the G.B. Pant Institute of Himalayan Environment & Development has initiated documentation of some of these practices, especially traditional and innovative soil nutrient management practices that help in sustaining agro-ecosystems with few external inputs.
As part of this documentation initiative, a survey was conducted in four selected villages to assess the status of the indigenous system of night-soil composting. Heads of households were interviewed between November 2003 and January 2004. The information recorded was also verified through personal observation of various field operations. All available past records, published research papers and other detailed information pertaining to the indigenous practice were also collected.
Poor soil fertility is a big hurdle to sustainable agriculture in these areas, as topsoil is removed and the rate of nutrient leaching is high, due to the abundance of snowfall, avalanches, landslides and erosion. In the cold and harsh climatic conditions of the region, with grass and vegetation cover being scanty, it is not possible to maintain enough cattle to produce adequate amounts of farmyard manure. Faced with this situation, the locals have traditionally relied heavily on obtaining organic manure derived from composting human excreta.
In earlier times, sheer necessity meant that farmers were able to overcome the revulsion associated with the practice of handling human excreta. Now, with the advent of modernisation and the easy availability of chemical fertilizers, people are distancing themselves from this age-old practice. Moreover, because of the large-scale adoption of modern septic toilets nowadays, farmers are forced to use chemical fertilizers to raise the yields of recently introduced cash crops like pea, potato and hop (Humulus lupulus).
Present scenario and future implications
Farmers do not want to use chemicals on crops, and they clearly know the consequences of continuous use of inorganic fertilizer in the same agricultural fields. They prefer to use organic inputs, however, supplies are limited, and subsidised chemical fertilizer is easily available. Despite the perceived benefits of night-soil compost, its use in the Lahaul valley is gradually decreasing.
The main reasons for this decline are: the unhygienic conditions of traditional toilets, the introduction of modern toilets, lack of workforce for the task, the increasing influence of outside culture/society, educational improvement and concerns of social status, and the easy availability of subsidised chemical fertilizer. In addition, the use of the traditional dry toilets which facilitated the conversion of night-soil into compost, is decreasing.
The practice of night-soil composting has completely vanished from some villages, while many other villages have gradually started discarding this traditional system since the 1980s. The production of night-soil compost is therefore under a severe threat of modernisation and is most likely to disappear in the near future if steps are not taken to save it.
Preparing night-soil compost
World Health Organization Guidelines for the safe use of wastewater, excreta and greywater
- Where faecal matter and other organic materials are composted at ambient temperature, the end-product of such an aerobic composting process does not smell and has good properties as a soils conditioner and slow-release phosphorus fertilizer.
- To minimize the health risks from using night-soil as a fertilizer, WHO makes various statements and recommendations. Where it is difficult to increase the temperature of the compost heap, WHO recommends “prolonged storage” to ensure safety. With ambient temperatures of 2-20oC, they note that storage times of one and a half to two years will “eliminate bacterial pathogens; will reduce viruses and parasitic protozoa below risk levels.”
- In addition, WHO recommends various precautions to “control exposure” to risk. Precautions for those handling night-soil include wearing personal protection such as boots, gloves and a facemask, and using tools or equipment not used for other purposes.
- At the time of applying the night-soil compost to the field, if the quality cannot be guaranteed, it is recommended to use “close to the ground application”, working the material in to the soil, and covering it. In addition, children should be kept away from all areas where night-soil is prepared, treated or has been applied.
- Finally, WHO notes that domestic and personal hygiene is very important. Technology alone cannot stop transmission of diseases, and communities must be aware of good hygiene practices. If treatment recommendations are followed, coupled with good general community hygiene, the risks to people who collect and use night-soil (as well as those consuming fertilized products) will be reduced to acceptable levels.
- World Health Organization, 2006. Guidelines for the safe use of wastewater, excreta and greywater. Volume IV: Excreta and greywater use in agriculture. Geneva, Switzerland
Villagers in Lahaul build traditional toilets on the first floor of the house attached to their living rooms. Through a rectangular hole (12” x 6”) in the toilet floor, the night-soil drops down to the ground floor, where the composting takes place. To avoid extra moisture content during composting, the use of water in these toilets is strictly disallowed.
After defecating, villagers cover the faeces with other materials, locally known as fot (dry cattle dung, kitchen ash, dry grass or leaves). This fot serves two main purposes: it makes the compost rich in nutrients, while it also prevents bad odours and keeps flies away.
For best results during the composting process the night-soil must be stored in two different chambers or vaults for a minimum period of six months. The first vault can be left to compost for six months while the other vault is being used. By alternately using the two vaults, proper compost can be obtained twice a year and night-soil compost can be made continuously by shifting from one vault to another.
Night-soil compost from the composting room is normally emptied in October/November and March/ April. The composting room has a special door for the removal of the compost. It is carried to the fields and dumped in a series of piles.
The heaps of compost remain in the fields for four or five months. Soon after the melting of the snow and before the beginning of the crop season, it is scattered all over the fields. This allows sufficient time for composting of the material, and the night-soil compost is then safe and fit for use. Due to the social stigma, this task is generally conducted during night time, particularly when there is a full moon.
To avoid nutrient losses, compost heaps should be protected against rainwater in the fields. Night-soil compost should be mixed with the soil before sowing the seeds, and the dosage has to be appropriate.
Associated health risks
The mixture of urine and faeces should never be used as it not only smells foul but also the slurry produced by this mixture has a high number of enteric micro-organisms. Urine can be treated by storing it separately for a period of six months; this makes it free of bacteria and safe for use in the fields. By consistently following these procedures, the presence of enteric bacteria, viruses, protozoa and helminth eggs in faeces can be fully controlled.
Some possible diseases due to partial treatment and unsafe use of night-soil compost are amoebic dysentery, human tapeworm, cholera or viral hepatitis. Safe and hygienic use of night-soil compost is important for protecting the health of the users, as well as the environment. In order to prevent diseases, proper management of night-soil and its treatment are essential. So for proper conversion of night-soil into compost, a series of control measures need to be followed. The World Health Organization has also produced guidelines relating to the safe use of wastewater, excreta and greywater (see Box).
The G.B. Pant Institute promotes night-soil as one of the organic farming practices in the region. Enhancement of soil nutrients through night-soil compost in the Lahaul valley is highly beneficial to the local inhabitants. The survey found that after proper treatment of night-soil through the double vault toilet system, the night-soil compost is free of pathogens, reducing health risks to the users. The survey also revealed that the use of night-soil compost can play a vital role in maintaining soil fertility and increasing the crop yield in a region that has a limited growth period (mid April-mid August).
This model of sustainable traditional soil management can be scientifically validated and may be replicated in many regions of the world, which could contribute to more efficient and chemical-free cropping systems.
Santaram S. Oinam
G.B. Pant Institute of Himalayan Environment & Development, North-East Unit, Vivek Vihar, Itanagar 791 113, Arunachal Pradesh, India.
- Drangert, J.O., 1998. Urine blindness and the use of nutrients from human excreta in urban agriculture. GeoJournal, 45: 201-208.
- Jonsson, H., A.R. Stinzing, B. Vinneras, and E. Salomon, 2004. Guidelines on the Use of Urine and faeces in Crop Production. EcoSanRes., 1-35.
- Kuniyal, J.C., S.C.R. Vishvakarma and G.S. Singh, 2004. Changing crop biodiversity and resource use efficiency of traditional versus introduced crops in the cold desert of the northwestern Indian Himalaya: a case of Lahaul valley. Biodiversity and Conservation 13 (7): 1271-1304.
- Mashauri, D.A., M.A Senzia, 2002. Reuse of nutrients from ecological sanitation toilets as a source of fertiliser. Water Resources Engineering Department, Dar es Salaam, Tanzania.
- Oinam, S.S., Y.S. Rawat, R.S. Khoiyangbam, K. Gajananda, J.C. Kuniyal, and S.C.R. Vishvakarma, 2005. Land use and land cover changes in Jahlma watershed of the Lahaul valley, cold desert region of the northwestern Himalaya, India. Journal of Mountain Science, 2 (2): 129-136.
The author is thankful to the Director, G. B. Pant Institute of Himalayan Environment and Development, Kosi-Katarmal, Almora (Uttarakhand) for providing necessary facilities; and the Indian Council of Social Science Research, New Delhi is also highly acknowledged for granting financial assistance to carry out this study.