UENR study portrays fermented urine as weed-control alternative

Research conducted by the University of Energy and Natural Resources (UENR) has validated fermented human urine as an effective natural herbicide for weed control, with no adverse effects on the tested crop.

The study, which used the Kuroda variety of carrot as the test crop, found that fermented urine suppressed weeds, improved carrot yields and had no adverse effects on selected soil properties or the nutritional value of the crop.

The findings could provide a locally available and environmentally friendly alternative to synthetic herbicides, whose improper use has raised concerns over environmental pollution and health risks.

Assess safety, effectiveness
The study, conducted by the Okuafopa Agribusiness Centre of UENR’s Dormaa Campus, was commissioned by the Centre for Indigenous Knowledge and Organisational Development (CIKOD) in May 2025 to scientifically assess the effectiveness and safety of fermented human urine as a natural herbicide.

The findings were presented at a dissemination workshop organised by CIKOD, with support from ActionAid Ghana, for state and non-state actors in the Transition Zone.

Presenting the findings in Techiman last Tuesday, an Agronomist at the Department of Agriculture and Crop Production at UENR, Dr Kwadwo Gyasi Santo, said the study assessed weed suppression, crop performance and quality, soil properties, and the concentration of selected heavy metals in the soil and plant parts.

He said the urine was stored in plastic bottles for two weeks to allow it to ferment before application, with the treatments applied two weeks before planting.

“Soil samples were analysed for properties including pH, nitrogen, phosphorus, potassium and carbon, while the crops were assessed for root length, diameter, weight, yield and nutritional quality,” he said.

Dr Santo said the results showed that fermented human urine killed weeds, improved carrot root yield and had no negative impact on the selected soil properties or carrot root quality.

Caution, concern
He, however, cautioned farmers against applying highly concentrated urine to growing crops, explaining that the research focused on its use as a pre-plant herbicide to clear weeds before planting.

Dr Santo said further studies should be conducted in other seasons and agroecological zones to confirm the consistency of the findings and explore its possible application on growing crops.

He expressed concern about the indiscriminate use of synthetic herbicides, explaining that some farmers failed to observe recommended application rates and did not wear protective clothing when spraying.

He also criticised the practice of washing agrochemical containers for domestic use and applying chemicals close to water bodies, adding that such practices could expose farmers, consumers and aquatic ecosystems to potential risks.

Weed management
The Director of Programmes at CIKOD, Mr Wilberforce Laate, said weed control was one of the major challenges facing agroecological farmers, with some resorting to synthetic herbicides because of the difficulty in managing weeds through sustainable methods.

He said the scientific validation had provided CIKOD and its partners with evidence to promote the innovation more confidently.

Mr Laata added that the organisation planned to collaborate with researchers to replicate the trials with other crops.

The originator of the innovation, James Opoakpajor of the Opoakpajor Youth and Development Centre, said he began experimenting with human urine in 2017 after suffering severe effects from exposure to agrochemicals.

He said using urine to control weeds added nutrients to the soil.

Climate change
The Banda District Director of Agriculture, Angel-Mmafiik Ayarick, described the findings as timely, particularly amid climate change and its effects on agricultural productivity and food security.

She called for the research to move beyond presentations into practical demonstration farms to enable farmers and extension officers to see the results and facilitate wider adoption.

She said stronger collaboration among researchers, civil society organisations, government agencies and farmers was needed to transform the findings into practical solutions for sustainable agriculture.