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Urine contains four important nutrients for plant growth: nitrogen (N), phosphorus (P), potassium (K) and sulphur (S). Urine application can not only recover these nutrients, but also reduce the use of complete fertilisers and freshwater, as well as minimise the contamination of surface and ground waters by wastewater and excreta.
However, if urine is not managed properly, the risk of pathogen transmission, soil salinisation and pharmaceutical contamination, as well as strong and offensive odour can cause significant health problems and discomfort. Other challenges that have to be addressed are separation techniques, storage time, amount of urine to be applied, odour prevention and transport. Find out more in the literature review.
This tool calculates the collectible urine volume per household and gives the user the potential fertilisation area for the amount of calculated urine. For more information on urine utilisation and its proper management, have a look at the further materials provided in the Toolbox.
Please keep in mind that the application rate of urine depends not only on its nutrient content, but also on the main goal of urine utilisation: N-Fertilisation or P-Fertilisation.
The following table gives the background information the calculator uses:
| Urine Values | Values | Unit | |
|---|---|---|---|
| Daily Urine Volume per Person | 1.5 | L/d | (litre per day) |
| Yearly Urine Volume per Person | 550 | L/a | (litre per year) |
| Yearly Amount of Nitrogen in Urine per Person | 4000 | g/a | (gram Nitrogen per year) |
| Volume of urine to be applied per squere meter (N-Fertilizer) | 1.4 | L/m² | (litre per square metre) |
| Yearly N-Fertilization Area per Person | 400 | m²/a | (square metre per year) |
| Yearly Amount of Phosphorous in Urine per Person | 365 | g/a | (gram Phosphorous per year) |
| Volume of urine to be applied per squere meter (P-Fertilizer) | 0.9 | L/m² | (litre per square metre) |
| Yearly P-Fertilization Area per Person | 600 | m²/a | (square metre per year) |
The Yearly Fertilisation Area per Household is calculated from the potential Yearly Fertilisation Area per Person (400 m2 for Nitrogen and 600 m2 for Phosphorous) multiplied by the number of household members.
The Yearly Amount of Nitrogen in Urine per Household is calculated from the potential Yearly Amount of Nitrogen in Urine per Person (4000 g/(a·person)) multiplied by the number of household members. The value for Phosphorous is calculated in the same way.
The values used in this calculation tool are based on Jönsson, H, Richert, A, Vinneraas, B & Salomon, E 2004, Guidelines on the use of urine and faeces in crop production, EcoSanRes Publication Series, 2nd edn, Stockholm Environment Institute, Stockholm, Sweden. This study takes as a reference point the average nutritional values for Sweden retrieved from FAO, which should be appropriated for the purposes of other countries. It is important to note that improved nutritional values also improve the quality of the urine as a fertiliser. The provided results should be considered just as a reference point, when referring to the potential for urine utilisation.
Urine Application Calculator by Andrea Munoz Ardila and Ruth Schaldach is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
