Sustainable Sanitation—A Cost-Effective Tool to Improve Plant Yields and the Environment

Human urine and faeces are products formed every day in every human society. The volume and fertilisation value of urine is higher than that of faeces. This paper reviews data that urine has been used successfully as a fertiliser for cereals and some vegetables. According to the literature, urine fertilised plants may have produced higher, similar or slightly lower yields than mineral fertilized plants but they invariably resulted in higher yields than non-fertilised plants. There have been no microbiological risks associated with any products. The taste and chemical quality of the products are similar to plants treated with mineral fertilisers. Separating toilets, where urine and faeces are separated already in the toilet, could be beneficial not only in poor but also in the industrialized countries. A separating toilet could be installed also in old buildings and it could allow individuals to live in coastal areas, mountainous or other sensitive environments. In poor areas, urine fertilisation could increase food production also in home plots and reduce hunger. It could also combat water contamination and help to reduce diseases caused by enteric micro-organisms. If urine were to be viewed as a resource rather than a waste product, more families could be encouraged to install low-cost toilets which would especially improve the