Urine’s Benefits to Agriculture
The following are examples of human urine’s use and impact in agricultural studies from around the world.
Urine has been tested as a fertilizer on amaranth in Mexico. Results show that a combination of urine and poultry manure gave the highest yield, 2,350 kg/ha. Chicken manure alone gave a yield of 1,900 kg/ha. Human urine alone gave a yield of 1,500 kg/ha and the unfertilized control gave a yield of 875 kg/ha. The amount of N applied was 150 kg N/ha for the three treatments. Soil sampling showed no differences between treatments regarding physical or chemical characteristics. (Clark, pers. comm., 2003).
Urine was tested as a fertilizer on barley in Sweden during 1997-1999. Results showed that the N effect of urine corresponded to about 90% of that of equal amounts of ammonium nitrate mineral fertilizers. (Johanssson et al., 2001; Richert Stintzing et al., 2001; Rodhe et al., 2004).
Red beets were fertilized with 133 kg of N/ha as mineral fertilizer, urine and ash, and only urine with no fertilizer as a control. The mineral-fertilized plants and urine- and ash-fertilized plants also received 89 kg of P/ha. Urine and ash and only urine fertilizer produced 1720 and 656 kg/ha more root biomass, respectively, versus what was obtained from the mineral fertilizer. The beetroots from the urine- and urine/ash–fertilized plants were found to be 10% and 27% larger by mass, respectively, than those grown in mineral fertilizer. By subjecting some of the beets to chemical analysis, the researchers determined that all of them had comparable nutrient contents—and according to a blind taste-testing panel, their beety taste was indistinguishable. (Pradhan et al., 2010)
Human urine was used as a fertilizer in cabbage cultivation and compared with industrial fertilizer and non-fertilizer treatments. Urine achieved equal fertilizer value to industrial fertilizer when both were used at a dose of 180 kg N/ha. Growth, biomass, and levels of chloride were slightly higher in urine-fertilized cabbage than with industrial-fertilized cabbage but clearly differed from non-fertilized cabbage. (Pradhan et al., 2007)
Human urine was compared with commercial fertilizer in the cultivation of outdoor cucumbers (Cucumis sativus L.) in a Nordic climate. The urine fertilization crop yield was similar or slightly better than the yield obtained from control rows fertilized with commercial mineral fertilizer. In the taste assessment, 11 out of 20 people could recognize which cucumber of three cucumbers was different but they did not prefer one over the other cucumber samples, since all of them were assessed as equally good. (Heinonen-Tanksi et al., 2007).
In a field trial in Sweden in 2002, different application strategies for urine as a fertilizer on leeks were tested. Fertilizing with urine gave a three-fold yield increase. Neither yield nor nutrient uptake was significantly affected by whether the same total amount of urine was applied in two doses or whether it was divided into smaller doses applied every 14 days.
The N efficiency (i.e. N yield – (N yield in unfertilized plots)/added N), when using human urine was high, ranging from 47% to 66%. This is on the same level as when mineral fertilizers are used. N efficiency for most other organic fertilizers, e.g. compost, is normally between 5 and 30%. (Båth, 2003).
Urine has been tested as a fertilizer on greenhouse-grown lettuce in Mexico There were treatments comparing urine with compost, a urine-compost mixture and no fertilizer at all. The application rate was 150 kg of total N per hectare in all treatments, except for the unfertilized one. Urine gave the best yield of lettuce, due to its high availability of N. (Guadarrama et al., 2002).
Human urine was compared with mineral fertilizer in pumpkin cultivation at a dose of 113 kg N ha-1 with no fertilization used as a control. The growth of the vine was better in urine fertilized pumpkins than in mineral fertilized and non-fertilized pumpkins. Total fruit biomass was higher in mineral fertilized pumpkins compared to urine fertilized and non fertilized pumpkins. Urine fertilized pumpkins may have suffered lower potassium or higher chloride, thus they produced fewer flowers and fruits. However, total fruit biomass and the number of fruits were slightly higher in urine fertilized plants than in their non-fertilized counterparts. (Pradhan et al., 2009)
Urine has been tested as a fertilizer on Swiss chard in Ethiopia. The yields of the fertilized plots were up to four times that of those unfertilized. (Sundin, 1999).
In field trials of winter wheat grown on organic farms during 1997-1999, human urine was compared with dried chicken manure and meat + bone meal On average, for all three N fertilization levels, the increase of the winter wheat yields was 18 kg grain per kg N for human urine, 14 kg for dried chicken manure and 10 kg for meat + bone meal. (Lundström & Lindén, 2001).
Båth, B. 2003. Field trials using human urine as fertilizer to leeks (In Swedish). Manuscript, Department of Ecology and Plant Production Science, Swedish University of Agricultural Sciences. Uppsala, Sweden.
Clark, G.A. 2003. A test of the production of organically fertilized amaranth in Tehuixtla, Morelos, Mexico. Manuscript available from firstname.lastname@example.org.
Guadarrama, R. O., Pichardo, N. A., Morales-Oliver, E. 2001. “Urine and Compost Efficiency Applied to Lettuce under Greenhouse Conditions in Temixco, Morales, Mexico”. In: Abstract Volume, First International Conference on Ecological Sanitation 5-8 November 2001, Nanning, China.
Heinonen-Tanski, H., Sjöblom, A., Fabritius, H., Päivi Karinen, P. 2004. “Pure human urine is a good fertilizer for cucumbers”. Bioresource Technology 98 (2007) 214–217.
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.
Jönsson, H., Richert Stintzing, A., Vinnerås, B., Salomon. 2004. Guidelines on the Use of Urine and Faeces, EcoSanRes Publications Series. Stockholm Environment Institute.
Lundström, C. & Lindén, B. 2001. Kväveeffekter av humanurin, Biofer och Binadan som gödselmedel till höstvete, vårvete och vårkorn i ekologisk odling. (Nitrogen effects of human urine and fertilizers containing meat bone meal (Biofer) or chicken manure (Binadan) as fertilizers applied to winter wheat, spring wheat and spring barley in organic farming) (In Swedish). Skara Series B Crops and Soils Report 8, Department of Agricultural Research, Swedish University of Agricultural Sciences. Skara, Sweden.
Pradhan, S.K., Holopainen, J.K., Weisell, J., and Heinonen-Tanski, H. 2010 “Human Urine and Wood Ash as Plant Nutrients for Red Beet (Beta vulgaris) Cultivation: Impacts on Yield Quality” Journal of Agriculture and Food Chemistry, 2010, 58 (3), pp 2034–2039. DOI: 10.1021/jf9029157 American Chemical Society, 2010.
Pradhan, S.K., Nerg, A., Sjoblom, A., Holopainen, J.K., and Heinonen-Tanski, H. 2007. “Use of Human Urine Fertilizer in Cultivation of Cabbage (Brassica oleracea)––Impacts on Chemical, Microbial, and Flavor Quality” Journal of Agriculture and Food Chemistry. 2007, 55, 8657–8663. American Chemical Society, 2007.
Pradhan, S.K., Pitkanen, S., Heinonen-Tanski, H. 2009. “Fertilizer value of urine in pumpkin (Cucurbita maxima L.) cultivation”. Agriculture and Food Science, Vol., 18 (2009): 57-68.
Sundin, A. 1999. Humane urine improves the growth of Swiss chard and soil fertility in Ethiopian urban agriculture. Thesis and Seminar projects No. 112, Department of Soil Science, Swedish University of Agricultural Sciences. http://www.vaxteko.nu/html/sll/slu/ex_arb_vaxtnaringslara/EVN112/EVN112.HTM