A scientific team from HU Berlin is testing outdoors whether sanitized fecal compost is safe for people and the environment. It could be used as an environmentally kind fertilizer in agriculture.
Could our waste be the future of farming? A team of researchers in Germany is investigating whether human fecal compost, after rigorous sanitation, can be safely used as fertilizer, potentially revolutionizing enduring agriculture. The study, conducted under real-world conditions, aims to determine if pathogens from human waste pose a risk to the food cycle.
Turning Waste into a Resource
Currently,German regulations only permit the use of human excreta for research,not agricultural application,due to concerns about potential contamination. Though, scientists are exploring the potential of human feces as a valuable resource within a circular economy, capable of recycling nutrients, conserving water and energy, and even storing carbon in the soil to combat climate change.
Positive Results from Field Trials
Scientists led by Prof. Dr.Timo Kautz of Humboldt University (HU) and Prof. Dr. Roland Hoffman-Bahnsen of the Eberswalde University for Sustainable Development (HNEE) tested compost created from feces collected from dry toilets. The compost underwent a two-step sanitation process: heating to 70 degrees Celsius for seven days, followed by ten weeks of composting with additives at high temperatures. The team monitored concentrations of Escherichia coli,enterococci,salmonella,and Clostridium perfringens – key indicators of fecal contamination – in soil over a period ranging from just under two months to over three years.
“We are doing pioneering work in our real laboratory to make the effect of fertilizer measurable in a practical way,” explained HU scientist Jan-Ole Boness. “The well-treated compost proved to be a safe fertilizer. No systematic increase in indicator germs could be found.” The research suggests that coarse-grained sandy soils are especially well-suited for this type of fertilizer application.
Why is this research happening? german regulations currently prohibit using human waste as fertilizer due to contamination concerns. Researchers are investigating if rigorous sanitation processes can make it safe and sustainable.
Who is involved? The study is led by Prof.Dr. Timo Kautz (Humboldt University) and Prof. Dr. Roland Hoffman-Bahnsen (Eberswalde University for Sustainable development), with contributions from HU scientist Jan-Ole Boness.
What did they do? Scientists tested compost made from human feces collected from dry toilets.The compost was heated and composted for an extended period, then applied to soil, and monitored for harmful bacteria.
How did it end? the field trials showed the treated compost was a safe fertilizer, with no meaningful increase in indicator germs detected in the soil over a period of up to three years. Future research will focus on long-term effects and different soil types.
Future research will focus on the long-term effects of repeated fertilization on different soil types and the impact on the soil microbiome. The ultimate goal is to provide a scientific foundation for updating regulations and promoting a more sustainable circular economy in agriculture.
