“Urine-derived fertilizer (UDF) is a safe, locally-sourced fertilizer that has been shownto be an effective replacement for synthetic nitrogen fertilizers. However, like other ammonium-containing fertilizers such as manure and urea, UDFs have the potential to lose significant amounts of nitrogen to ammonia volatilization.” That volatilization can produce green house gases. This is from a study published by SARE: Sustainable Agriculture Research and Education conducted by over a dozen scientists. The grant recipient for the study was The Rich Earth Institute. The project leader was Abraham Noe-Hays. Click here to download it.