Nelly Bassily | January 16, 2012
Livestock farmers in this heavily agricultural nation are becoming unlikely heroes in Africa’s fight to curb greenhouse gas emissions.
Every year in Cameroon, thousands of trees are cut down for wood and charcoal. These are the main sources of cooking fuel for the rural dwellers who make up over 65 per cent of Cameroon’s population. Livestock farmers, like other rural people, are starved for electricity. But they have plenty of manure. Now, that manure is yielding valuable methane gas when processed in biodigesters.
Forty-six-year-old Juliana Mengue was widowed five years ago. She cares for 40 cows by herself, on her half-hectare farm in Bafut village in northwest Cameroon. Traditionally, cattle manure is used as fertilizer for crops. But a new government program, established with the help of global non-profit Heifer International, is turning her animal manure into fuel. As a result of the cheap biogas she now produces, Mrs. Mengue is able to spend more on medical care, education and increasing her animal stock. She says, “We also use (the biogas) for lighting and heating, replacing our local bush lamps and the use of wood fuel.”
The project has established demonstration biogas production centres in her village and two nearby villages. Many farmers say the technology has brought meaningful changes in their lives and to their community, especially given the spiralling cost of fuel.
Henry Njakoi is country director for Heifer International in Cameroon. He says that building biogas digesters on demonstration farms can generate enough gas for whole communities. Farmers pay only a quarter of the $120 US dollar cost of a manure biodigester, with Heifer International and the Ministry of Agriculture picking up the rest of the tab.
To produce biogas, farmers collect dung from their livestock and carry it by wheelbarrow to the biodigester’s tank. They mix the manure with an equal amount of water and stir. The mixture is left to decompose for several weeks, and the resulting methane gas settles in an upper compartment of the tank. At the end of the process, the manure is removed, dried and used as fertilizer. The technology is affordable enough that many livestock farmers can integrate it with traditional practices without major financial assistance.
Mr. Mengue says her family has not only gained financially from the project, but that she now has a greater understanding of the connection between the environment and climate change. “We were not aware how much destruction the decomposing dung was doing to the environment. Now we have been told it releases tonnes of methane gas that is very harmful,” she says.
Methane released from manure is a potent driver of climate change. Global efforts to curb its release range from capturing the gas to produce biofuel, to changing livestock diets to produce less methane.
Micheal Mbu raises pigs and goats and cares for 50 cows. He says the biodigestion process is simple enough for any farmer to understand. He believes that it will ensure a consistent profit, especially for those who use the new source of energy in income-generating projects. Mr. Mbu has connected the methane pipes to 10 cookers with two burners each, which ensures a constant supply of fuel. He adds, “I use the energy to bake potatoes and flour cake and bread. This cottage baking industry employs five persons.”
The manure generated by the biodigester is high in the nutrients needed by plants, and is an effective fertilizer. Eugene Ejolle Ehabe works with the Institute of Agricultural Research and Development in northwest Cameroon. He says that making biogas from manure and other waste matter could reduce the large volumes of fuel wood used for cooking. He continues, “The production of biogas will reduce emissions of greenhouse gas, reduce deforestation, help preserve the forest and soil fertility, and above all improve the livelihood of farmers.”