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Guidelines on the use of urine and faeces in crop production

Authors:
Anna Richert Stintzing at World Wildlife Fund
Anna Richert Stintzing
Håkan Jönsson at Swedish University of Agricultural Sciences
Håkan Jönsson
Björn Vinnerås at Swedish University of Agricultural Sciences
Björn Vinnerås
Eva Salomon at RISE Research Institutes of Sweden
Eva Salomon
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Abstract

International guidelines have been presented within the Sida financed EcoSanRes programme for the use of human urine and faeces in crop production based on the current knowledge on use of urine and fae- ces in small and large-scale cultivation. Urine and faeces are each a complete fertiliser of high quality with low levels of contaminants such as heavy metals. A basis for the recommendations for agricultural use is the knowledge of the contents of nutrients in the excreta, the amounts excreted, composition and plant avai- lability of the plant nutrients, as well as the good knowledge of how the product has been sanitised. Urine is a quick-acting nitrogen rich fertiliser that can be applied as it is or diluted. Faeces are rich in phospho- rous, potassium, micronutrients as well as organic matter. Well documented research in this area is needed.
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GUIDELINES FOR THE USE OF HUMAN URINE AND FAECES
IN CROP PRODUCTION
A. Richert Stintzing1, H. Jönsson2, B. Vinnerås2, E. Salomon3
1VERNA, Malngårdsvägen 14, 116 38 Stockholm, Sweden. anna@verna.se
2Dept of Biometry and Technology, Swedish University of Agricultural Sciences, Box 7032,
750 07 Uppsala, Sweden
3Swedish Institute of Agricultural and Environmental Engineering, Box 7033, 750 07 Uppsala,
Sweden
ABSTRACT
International guidelines have been presented within the Sida financed EcoSanRes programme for the
use of human urine and faeces in crop production based on the current knowledge on use of urine and fae-
ces in small and large-scale cultivation. Urine and faeces are each a complete fertiliser of high quality with
low levels of contaminants such as heavy metals. A basis for the recommendations for agricultural use is
the knowledge of the contents of nutrients in the excreta, the amounts excreted, composition and plant avai-
lability of the plant nutrients, as well as the good knowledge of how the product has been sanitised. Urine
is a quick-acting nitrogen rich fertiliser that can be applied as it is or diluted. Faeces are rich in phospho-
rous, potassium, micronutrients as well as organic matter. Well documented research in this area is needed.
INTRODUCTION
Urine and faeces from human beings are valuable resources that deserve a better fate than to
end up in surface waters as well as groundwater, where they can cause significant problems. In
regions where there is a lack of domestic financing of fertilisers for subsistence production of
food, collected urine and faeces can contribute significantly to food security and health. Source
separated urine and faeces are collected in sanitation systems designed for this, e.g. urine diver-
ting toilet systems (Johansson et al, 2001). Treatment of urine and faeces in order to minimise
the hygiene risk is important, as well as guidelines for how to use the fertiliser in crop produc-
tion that will enable proper use with minimal risk for users of the system.
MATERIALS AND METHODS
These guidelines for use of urine and faeces in crop production have been produced through
collection of experiences, documented as well as undocumented, of reuse of urine and faeces as
fertiliser. Countries where human urine and or faeces have been studied are South Africa,
Zimbabwe (Morgan, 2003), Ethiopia, Mocambique, Benin, Burkina Faso, Senegal, Cote d´Ivoire,
Togo, Mali, Mexico (Guadarrama et al, 2001), China, Sweden (Kirchmann & Pettersson, 1995,
Johansson et al, 2001, Rodhe et al, 2004) and Germany (Simons & Clemens, 2004) although
many of these experiences are not yet scientifically published. The basis for the work has also
been current plant nutrient knowledge through a literature study. A reference group consisting of
international experts has been consulted in order to assure the relevance of the guidelines.
Dissemination of the guidelines is carried out though the publication of results at conferences, as
well as thought the Internet, and the guidelines can be downloaded at www.ecosanres.org. The
authors gratefully accept comments, as updating will need to take place continuously.
357
Waste Management Strategies
RESULTS AND DISCUSSION
Recommendations for agricultural use of excreta are based on knowledge of the nutrient con-
tent of the excreta, the amounts excreted, and the treatment of the excreta, which influences their
properties. Table 1 shows the proposed default values for excreted mass and nutrients from one
person on a Swedish diet. Adapting of the guidelines to local conditions is necessary since diets,
as well as plant production conditions vary. Excreta should be handled and treated according to
hygiene guidelines for safe reuse (Schönning & Stenström, 2004) before use in cultivation.
Urine and faeces are each a complete fertiliser of high quality with low levels of contami-
nants such as heavy metals (Palmquist & Jönsson, 2004). Urine is rich in nitrogen, while faeces
are rich in phosphorous, potassium and organic matter.
Specific local recommendations for use of urine and faeces in cultivation should be based on
local recommendations for fertilisation of crops. Application rates for commercial mineral nitro-
gen fertilisers (urea or ammonium if available) can be used as a basis for recommendations on
the use of urine. Before translating such recommendations to urine, its nitrogen (N) concentra-
tion should preferably be analysed. Otherwise, it can be estimated at 3-7 g N per litre. If no local
recommendations can be obtained, a rule of thumb is to apply the urine collected from one per-
son during one day (24 hours) to one square metre of land and cropping period. If all urine is
collected, it will suffice to fertilise 300-400 m2of crop per person and year with N at a reasona-
ble rate. For most crops, the maximum application rate, before risking toxic effects, is at least 4
times this application rate. Urine also contains phosphorus, and it will suffice to fertilise up to
600 m2of crop per person and growing season, if the application rate is chosen to replace the
phosphorus removed, as for faeces below.
Urine can be applied neat or diluted. However, the application rate should always be based
on the desired nutrient application rate and any potential need for supplementary water should
be met with plain water. To avoid smells, loss of ammonia and foliar burns urine should be
applied close to the soil and incorporated as soon as possible. Irrigation after application of urine
is beneficial.
Urine is a quick-acting fertiliser whose nutrients are best utilised if the urine is applied from
prior to sowing up until two-thirds of the period between sowing and the harvest. The best fer-
tilising effect is achieved if urine and faeces are used in combination with each other, but not
necessarily in the same year on the same area. The amount of urine to be spread can be applied
in one large dose or in several smaller doses, and under most circumstances the total yield is the
same for the same total application rate.
For faeces, the application rate can be based on the local recommendation for the use of
phosphorous-based fertilisers. This results in a low application rate, and the improvement due
to the added organic matter is hard to distinguish. However, faeces are often in the smaller scale
applied at much higher rates, at which the structure and water-holding capacity of the soil are
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Sustainable Organic Waste Management for Enviromental Protection and Food Safety
Parameter Unit Urine Faeces
Wet mass kg/person,year 550 51
Dry mass kg/ person,year 21 11
Nitrogen g/ person,year 4000 550
Phosphorus g/ person,year 365 183
Table 1. Proposed new Swedish default values for excreted mass
and nutrients (Vinnerås, 2002).
visibly improved as an effect of its content of organic matter. Both organic matter and ash are
often added to the faeces and they improve the buffering capacity and the pH of the soil, which
is especially important on soils with low pH. Thus, depending on the application strategy, the
faeces from one person will suffice to fertilise 1.5-300 m2, depending on whether they are
applied according to their content of organic matter or phosphorus. Faeces should be applied and
mixed into the soil before cultivation starts. Local application, in holes or furrows close to the
planned plants, is one way of economising on this valuable asset.
Pharmaceuticals and hormones are excreted with the urine, and the discussion has been rai-
sed whether to restrict use of urine on this account. Documented effects of pharmaceutical resi-
dues almost entirely reported for aquatic systems, rather than terrestrial systems. Many reports
have been published on adverse effects on organisms in watercourses where wastewater is rele-
ased. However, soil microorganisms are better adapted to decomposing hormones and other
organic substances than are aquatic organisms and the soil-root barrier is very tight against orga-
nic molecules. Thus, the risk when using urine from human beings as fertiliser on soil is small,
since the microbes in the soil system are good at decomposing the excreted pharmaceutical resi-
dues. This will always be a better strategy for the environment than to emit the products into
aquatic systems, as is the case for conventional wastewater systems with WC.
Further research on the use of urine and faeces as fertilisers is needed, especially in the follo-
wing areas:
• Nutrient effects of excreta on crops and soil
• Fertilisation strategies and application techniques when using excreta
• Efficiency of short term storage of urine in soil
• Simple and resource-efficient sanitation techniques for faeces
These guidelines have been developed within the EcoSanRes programme, funded by Sida,
the Swedish International Development Cooperation. The full text of the guidelines can be
downloaded from www.ecosanres.org.
CONCLUSIONS
• Reuse should be safe, e.g. the hygiene guidelines on use of excreta for crop production
(Schönning & Stenström, 2004) should be followed.
• Urine and faeces supplement each other as fertilisers, urine is rich in nitrogen that is
quickly available, while faeces is rich in rich in phosphorus, potassium and organics and
its nutrients are not that readily available.
• The chemical contamination of urine and faeces is minimal and the levels of e.g. heavy
metals are very low. Pharmaceuticals residues are excreted via urine and faeces.
However, the soil-root barrier is very efficient and therefore the risk with these substan-
ces is probably far smaller than that associated with e.g. insecticides, fungicides and her-
bicides applied to crops.
• As these fertilisers contain all the elements removed from the field by the crop, their use
decreases both the need of soil analyses and the risk for soil depletion.
• Reuse of urine and faeces as fertilisers essentially eliminates the risk that their nutrients
pollute the environment and it enables sustainable crop production.
REFERENCES
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Waste Management Strategies
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Johansson, M., Jönsson, H., Höglund, C., Richert Stintzing, A., Rodhe, L. 2001. Urine separation – closing
the nutrient cycle. Stockholm Water Company. Stockholm, Sweden. Available at: http://www.stoc-
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Kirchmann, H., Pettersson, S. 1995. Human urine – chemical composition and fertilizer efficiency.
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Morgan, P. 2003. Experiments using urine and humus derived from ecological toilets as a source of
nutrients for growing crops. 3rd World Water Forum 16-23 March 2003.
http://aquamor.tripod.com/KYOTO.htm.
Palmquist, H., Jönsson, H. 2004. Urine, faeces, greywater, greywater and biodegradable solid waste as
potential fertilisers. In: Ecosan – closing the loop. Proceedings of the 2nd International Symposium on
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Rodhe L., Richert Stintzing A., Steineck S. 2004. Ammonia emissions after application of human urine to
clay soil for barley growth. Nutr. Cycl. Agroecosys., 68: 191-198.
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Vinnerås, B. 2002. Possibilities for sustainable nutrient recycling by faecal separation combined with urine
diversion. Agraria 353, Acta Universitatis Agriculturae Sueciae, Swedish University of Agricultural
Sciences. Uppsala, Sweden.
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Article
  • Feb 2004
Important amounts of plant nutrients excreted by humans are found in human urine. This provides the motivation for separating urine and recycling it, as fertiliser, back to agricultural land for food or fodder production. There are some housing estates in Sweden, both blocks of flats and separate houses, in which urine-separating toilets have been installed. The urine is stored in covered basins and spread on agricultural land. The objective of the present study was to evaluate the influence of application rate, application techniques and time on NH3 emissions after application of source-separated human urine. Human urine was spread at different application rates (10, 20 and 60 Mg ha–1) before sowing (year 1 to 3) and when the barley crop was 20-30 cm high (year 2). Urine was spread with a plot spreader using two band-application techniques (with bands 0.25 m apart): trailing hoses and trailing shoes. In spring, band-spread urine with trailing hoses was incorporated with a harrow four hours after application. The four (year 1 and 3) or six (year 2) treatments were organised into a randomised block design with three replicates. An equilibrium concentration method was used for measuring ammonia emissions directly after application. After spring application with trailing hoses and harrowing after four hours, the nitrogen [N] loss as ammonia [NH3], average over 3 years, was 5% of the applied N, irrespective of the application rate. The largest loss (10% of the applied N) was measured after application of 60 t of urine per hectare in spring. Hardly any NH3 loss occurred after incorporation with a harrow, with the exception of the highest application rate. Loss of NH3 was very low, close to 1% of the applied N, when the urine was incorporated directly into the soil in spring by band application with trailing shoes. Virtually no emissions were detected when the urine was applied to the growing crop, neither by trailing hoses nor by trailing shoes. This study shows that it is possible to apply human urine on bare soil or in growing barley crop with very low losses of N as NH3. Together with careful handling and the use of covered storage, nutrients in human urine could be recycled from households to agricultural land with low NH3 emissions.
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Human urine - Chemical composition and fertilizer use efficiency
Article
  • Jan 1994
Stored human urine had pH values of 8.9 and was composed of eight main ionic species (> 0.1 meq L–1), the cations Na, K, NH4, Ca and the anions, Cl, SO4, PO4 and HCO3. Nitrogen was mainly (> 90%) present as ammoniacal N, with ammonium bicarbonate being the dominant compound. Urea and urate decomposed during storage. Heavy metal concentrations in urine samples were low compared with other organic fertilizers, but copper, mercury, nickel and zinc were 10–500 times higher in urine than in precipitation and surface waters. In a pot experiment with15N labelled human urine, higher gaseous losses and lower crop uptake (barley) of urine N than of labelled ammonium nitrate were found. Phosphorus present in urine was utilized at a higher rate than soluble phosphate, showing that urine P is at least as available to crops as soluble P fertilizers.
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Urine and compost efficiency applied to let- 359 Waste Management Strategies r360 Sustainable Organic Waste Management for Enviromental Protection and Food Safety tuce under greenhouse conditions in Temixco
  • R O Guadarrama
  • N A Pichardo
  • Morales
  • E Oliver
Guadarrama, R. O., Pichardo, N. A., Morales-Oliver, E. 2001. Urine and compost efficiency applied to let- 359 Waste Management Strategies r360 Sustainable Organic Waste Management for Enviromental Protection and Food Safety tuce under greenhouse conditions in Temixco, Morales, Mexico. In Abstract Volume, First International Conference on Ecological Sanitation 5-8 November 2001, Nanning, China
Urine, faeces, greywater, greywater and biodegradable solid waste as potential fertilisers In: Ecosan – closing the loop
  • 7-11
  • H Palmquist
  • H Jönsson
Palmquist, H., Jönsson, H. 2004. Urine, faeces, greywater, greywater and biodegradable solid waste as potential fertilisers. In: Ecosan – closing the loop. Proceedings of the 2nd International Symposium on Ecological Sanitation, Incorporating the 1st IWA Specialist Group Conference on Sustainable Sanitation, 7th-11th April, Lübeck, Germany, pp. 587-594
Experiments using urine and humus derived from ecological toilets as a source of nutrients for growing crops. 3 rd World Water Forum 16-23
  • Apr 2003
  • P Morgan
Morgan, P. 2003. Experiments using urine and humus derived from ecological toilets as a source of nutrients for growing crops. 3 rd World Water Forum 16-23 March 2003. http://aquamor.tripod.com/KYOTO.htm.
Urine separation – closing the nutrient cycle. Stockholm Water Company
  • Jan 2001
  • M Johansson
  • H Jönsson
  • C Höglund
  • Richert Stintzing
  • A Rodhe
Johansson, M., Jönsson, H., Höglund, C., Richert Stintzing, A., Rodhe, L. 2001. Urine separation – closing the nutrient cycle. Stockholm Water Company. Stockholm, Sweden. Available at: http://www.stockholmvatten.se/pdf_arkiv/english/Urinsep_eng.pdf.
Guidelines for the safe use of urine and faeces in ecological sanitation systems EcoSanRes report 2004-1. Available at www.ecosanres.org Simons The use of separated human urine as mineral fertiliser
  • May 2003
  • 595-600
  • C Schönning
  • T A Stenström
  • J Clemens
Schönning, C., Stenström, T. A. 2004. Guidelines for the safe use of urine and faeces in ecological sanitation systems. EcoSanRes report 2004-1. Available at www.ecosanres.org Simons, J., Clemens, J. 2004. The use of separated human urine as mineral fertiliser. In: Ecosan – Closing the loop. Proceedings of the 2 nd International symposium on ecological sanitation, incorporating the 1 st IWA specialist group conference on sustainable sanitation, 7 th -11 th April 2003, Lübeck, Germany. pp 595-600.