Scientists in France are progressing research and trials to determine the benefits of and prospects for using human urine as an alternative to chemical fertiliser to grow their crops.

The human urine is collected from urban areas, bars and music festival urinals.

The French Chamber of Agriculture, a body similar to that of Teagasc in Ireland, is conducting human urine trials on crops in a number of locations, including on plots of wheat at Saclay, Essonne.

The researchers in Essonne say they are spreading it on their crops to find a cheap and sustainable fertiliser alternative.

Festival toilets

Lucie Baron of the French Chamber of Agriculture said: “[The urine] comes in part from festival toilets that have been collected by a company.”

Her research colleague Christophe Dion added that “obviously, with the soaring prices of fertilisers, this type of fertiliser which comes from urban areas is obviously a major interest provided that there is availability”.

Spraying human urine on crops may have some challenges with social acceptabilty, say researchers. \ Philip Doyle

The researchers report that early trials using the human urine as a fertiliser on crops are showing positive results.

“The yield was almost equivalent and the quality of the grain was good,” said Dion.

Bar owners providing the urine to the French Chamber of Agriculture researchers say that from those who realise their urine is being used for this purpose, the feedback is positive.

Ongoing studies

Research on the use of human urine as a fertiliser for crops in France has been ongoing for a number of years.

The “OCAPI” research programme was first launched in France in 2014. While studies began eight years ago, those involved now say they have found a “unique natural alternative” to chemical fertilisers.

The programme is working to explore the potential of urine diversion and to find new and alternative “decentralised approaches” of human urine and faeces management.

The researchers’ latest objectives include adapting urine source separation strategies to “different urban patterns” and to support those companies seeking to do this at regional, national and international level.

Reducing dependence on imported fertiliser

In December 2020, the Note Rapide L’institut published a report which estimated that 29m baguettes could be produced daily from wheat fertilised using urine from the 12.1m people in the Paris region, equivalent to 10 times their current daily consumption.

The institute reported that a spraying trial on a field of bread wheat on the Saclay Plateau showed that natural urine-based fertiliser has similar fertilising potential to synthetic fertilisers.

While the publication noted that the practice of using human urine on crops has the potential to greatly improve tillage sustainability and reduce the reliance on imported chemical fertilisers, it said that the social acceptability of this practice “is also an issue”.

However, the institute concluded: “While adapting to climate change plays a growing role in public policy, the utilisation of urine-sourced nitrogen and phosphorus is emerging as a promising way of helping France to achieve its zero net emissions goal by 2050.”