Research project results in higher crop yields, jobs

At the centre of a research project creating circular economies is the use of processed organic waste and human excreta as fertiliser or animal feed, resulting in higher crop yields and new jobs. Picture: Reuters

At the centre of a research project creating circular economies is the use of processed organic waste and human excreta as fertiliser or animal feed, resulting in higher crop yields and new jobs. Picture: Reuters

Published Nov 28, 2022

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Cape Town - Human excreta is being used as fertiliser or animal feed, resulting in higher crop yields, a research project on the continent has found.

Researchers from the Swiss Federal Institute of Technology in Zurich, Switzerland (ETH Zurich) together with partners in South Africa, Ethiopia, Rwanda and the Democratic Republic of the Congo are creating circular economies that use processed organic waste and human excreta as fertiliser or animal feed, resulting in higher crop yields and new jobs.

The project is called the Rural-Urban Nexus: Establishing a Nutrient Loop to Improve City Region Food System Resilience (Runres). The Runres research for development project, is funded by the Swiss Agency for Development and Cooperation (SDC).

Researchers explain that around 250 million Africans – 1 in 5 people on the world’s second-largest continent – suffer from hunger or malnourishment. One reason for this, they say, is that agricultural soils have not been receiving enough nutrients.

At the same time, many cities in sub-Saharan Africa face challenges with their sanitation and solid waste management, in many places, rapid urbanisation is overstraining the waste and sanitary infrastructure.

ETH Zurich’s Sustainable Agroecosystems research group, led by Professor Johan Six said: “We want to establish regional circular economies in which local people reuse nutrients from faecal matter and organic waste as fertiliser for growing food or as animal feed.”

Ideas for this project in South Africa were sparked in part when in 2017, community members from the Blessed Agricultural Co-operative in Vulindlela peri-urban settlement near Howick within the Msunduzi Municipality approached the University of KwaZulu-Natal’s (UKZN) School of Agriculturals, Earth and Environmental Science (SAEES) Dr Alfred Odindo for assistance in addressing challenges of waste disposal, since their 10-year-old Ventilated Improved Pit (VIP) latrines were full and the municipality had no plans to empty them.

The goal was to achieve safe sanitation, improved nutrition for mostly poor city dwellers and rural smallholder farmers, as well as environmental protection.

Benjamin Wilde, a native of Texas and a postdoc at the Chair of Sustainable Agroecosystems, is trying to solve this problem together with local partners in the Msunduzi municipality.

“We’re working with the local company Duzi Turf, a public utility, and the municipality to produce compost from sewage sludge and urban green waste. This is then used as fertiliser,” Wilde said.

Similarly to South Africa, the Runres project in Bukavu, in the eastern Democratic Republic of Congo, is about producing compost from organic waste.

To improve the collection of this waste in the city, Runres social scientist Leonhard Spaeth worked with researchers from the International Institute of Tropical Agriculture (IITA) to conduct an education campaign that encouraged residents to better separate household organic waste.

“Sorting behavior at household level is essential for getting an efficient and cost-effective process-chain from waste to usable input for agriculture,” Spaeth explains.

Recycling organic waste is central to another Runres project as well. In Kigali, Rwanda’s capital city, the ETH Zurich researchers are working together with a local company that collects organic waste and feeds it to the larvae of the black soldier fly.

Rwanda still imports most of its animal feed.

Small farmers cannot afford these expensive imports. The fly larvae are a cheap and locally produced alternative that creates jobs and reduces waste management costs.

In each of the four African countries where Runres operates, it employs at least two well-connected local project assistants who have intimate knowledge of the country.

During the project’s initial phase, which ends in the first half of the coming year, the researchers aim to demonstrate that their concept of regional circular economies works: soil health is building, while waste water management has improved; agricultural yields are increasing, while new jobs are being created and the exchange of knowledge and experience is working.

In the second phase, which will last until 2027, the ETH Zurich researchers and their partners in Africa intend to expand their projects.

The goal is for them to become self-sustaining activities - without SDC assistance.

Cape Times