Could what is flushed away in conventional toilets instead become a valuable resource in the garden or agriculture? New research gives a very interesting answer: yes!
A scientific study published in Agroecology and Sustainable Food Systems has examined leachate from composting toilets and its potential as a liquid fertilizer.
The results are highly promising:
- Comparable to synthetic fertilizers: The leachate produced growth in tomato and hemp plants comparable to that achieved with both traditional synthetic fertilizers and vermicompost.
- Increased yields: In field trials, hay yields increased when the leachate was used as a fertilizer. The potassium content of the hay also increased.
- No negative impact on the root microbiome: The researchers found no undesirable changes in the plants’ root microbiomes compared to the control treatments.
This represents an important step toward viewing human-derived nutrients as a resource rather than as waste.
At CompostEra, we are developing waterless composting toilets that make it possible to recover nutrients and create local nutrient cycles—even in locations lacking water, sewage systems, or electricity. Imagine if the toilets of the future were not just about sanitation, but also about contributing to more sustainable agriculture. From toilet to soil—and back again. That is the circular economy in action!