Ghana: Researchers turn human waste into farmer resource

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Ghana: Researchers turn human waste into farmer resource

In the West African nation of Ghana, farmers participate in what the International Water Management Institute (IWMI) describes as an "informal sludge market," taking it upon themselves to convert human waste into crop fertilizer.

Turning waste into a viable resource, Photo: IWMI West Africa

Josiane Nikiema, an IWMI researcher working on fertilizer solutions, explained a waste situation where both the environment and human health are being put at risk.

"In the northern part of Ghana, they are already using fecal sludge. They have different ways but one is to dig a hole in the farm and they make some informal arrangements with those who are entering the latrines and they will come there and pour the material there," she said.

"The way it is done, the way people are in contact with it, people are scared of it and authorities are not promoting it. There are some risks for the person who is operating it. Most of them have not been to school and don’t necessarily know the challenges associated with digging this sort of material."

Nikiema and her IWMI team are looking for a way to avoid risky behavior and make such fertilizer a viable, cheap resource for local farmers.

"What we would like to do is really provide something that will be safer, that is produced in an environment that allows the safety aspect to be controlled," she said.

The "Fertilizer Pellet Fertilization Project" seeks to sanitize the sludge and market a pathogen-free, organic fertilizer.

Through composting or irradiation, the team sanitizes the potentially deadly waste.

In the composting process, the material will be heated to 150°F (65°C) for up to a week to destroy pathogens. Irradiation has also been explored but due to cost and lack of facilities, it is not a preferred sanitation method.

Although the product is still in testing, Nikiema said it compares well to other available alternatives.

"The fertilizer we’ve developed, it contains less nutrients than conventional inorganic fertilizers but it contains more nutrients than other organic elements, other organic fertilizers," she said.

"What is interesting is when you apply the product we have developed, is that you’re also adding organic matter to the soil, which you don’t have with an inorganic fertilizer. If you compare this to other organic fertilizers such as poultry manure, the impression of nutrients is slightly higher."

Beyond providing an economical option to farmers, Nikiema also spoke on the environmental accept of resourcing human waste.

In the coastal city of Accra, for example, over 90% of collected excrement goes directly to the ocean, according to the IWMI.

Lack of facilities leaves few options for sanitary disposal, the researcher explained.

"What we would like to do is by developing something that can be sold that can generate revenue, they will have the expenses to maintain the system well. If they make money out of it and it is not just waste, they can transform it, upgrade it and get something that is very good. Then they will have the motivation to do it well and not just dump it in the sea," she said.

Nikiema expected more conclusive results on the soil pellets next year. For now, the researchers hope to produce material worthy of consumer confidence.

"If you can prove that it works, then you are okay. They just need us to confirm that it will be good for them if they use it and if so, they are willing to do it," she said.

The project is sponsored by the Bill and Melinda Gates Foundation through the Grand Challenges Explorations Program.

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