In cattle-rich Ethiopia, young men and women are helping to turn a wasted resource — discarded animal bones — into fertilizer, and they’re making money collecting this previously untapped source of nutrients, according to a report in Ensia, a magazine that showcases environmental solutions in action.
Calcium and phosphorus are nutrients in short supply in the country’s acidic, depleted soils, but they’re readily available in the mounds of discarded animal bones at garbage dumps and slaughterhouses around the country.
About 80 percent of Ethiopia’s population works in agriculture, and for the country’s 80 million farmers, fertilizer is unaffordable. The result is stunted crops — a common sight worsened by the devastating drought. More than 10 million Ethiopian households will need food aid this year, Ensia reports.
In 2011, the U.S. Embassy in Ethiopia spent $15,000 funding an agricultural research partnership with New York’s Cornell University and Ethiopia’s Jimma University. The goal was to improve food production in light of climate change. Phosphorus and the potential of discarded animal bones quickly became the focus of the project.
“There were piles of bones that nobody was using at the time,” said Dawit Solomon, an Ethiopian native and Cornell University soil scientist. Solomon and colleagues decided to turn goat, sheep and cattle bones into a local fertilizer source.
They estimated in 2013 that 212,000-to-364,000 tons of bone waste a year from livestock could yield up to 58 percent of annual phosphorus supplies to the country — saving the country up to $104 million a year in fertilizer imports.
The plan was to collect bones and burn them at high temperatures, a process known as pyrolysis, which kills harmful microbes and makes phosphorus in the bone powder more available to plants when added to the soil.
Cornell agricultural economist Garrick Blalock and students from Cornell and Jimma were in uncharted territory. One of their challenges was how to make slow-release fertilizer pellets familiar to farmers using Ethiopia’s existing technology. They finally found a winning strategy and are now supporting development of low-cost machinery to produce the fertilizer anywhere in Ethiopia, Ensia reported.
The team raised $200,000 in funds and recently produced the first bags of Abyssinia Phosphorus — Ethiopia’s first indigenous fertilizer, according to the U.S. Embassy’s Facebook page in Addis Ababa.
It has grown into a multi-million dollar partnership, according to the U.S. State Department.
Using bone char was up to 30 percent cheaper than commercial fertilizer, and early trials of Abyssinia Phosphorus showed that fertilizers with bone char doubled yields compared to unfertilized soils. There also appears to be no cultural aversion to it — something that researchers couldn’t count on when the project began, Ensia reported.
Phosphorus is in short supply worldwide, according to Ensia. Six countries control 90 percent of the global phosphate rock supply. Morocco owns the world market, with 50 million tons of the world’s 69-million-ton total. China is a distant second with 3.7 million tons. Conventional fertilizer costs in Africa are typically twice the international rate, and transport costs are about seven times more than in the U.S.
One challenge for the researchers is how to maintain a steady supply of bones. Once the bone collectors deplete the existing supply in city dumps, restaurants, streets, butcher shops and waterways, will there still be a cheap, fresh-bone supply?
So far, it hasn’t been a problem. In fact, the opposite is true. A bigger problem has been where to store all the bones that have been collected since word went out.
Early bone collection efforts, which started in January 2016, were so successful that the team had to stop collection until they could build additional storage. They were getting 400 kilograms (900 pounds) of bones a day, Ensia reported. Based on the law of supply and demand, they lowered the amount they were paying bone collectors from about 4.5 cents per pound for the bone to 2.8 cents per pound.
“It’s beyond our expectation,” Solomon told Ensia. “We’re working to speed up the conversion of bones into fertilizer so we can quickly take care of stocks and make space for more.”
The ultimate goal is to create a public-private partnership to get bags of fertilizer on the market.
“Where all these bones are located, if they can be collected efficiently and at what price are all equally up in the air,” said Johannes Lehmann, a soil fertility specialist at Cornell.
Blalock calls it a win-win-win project. “It creates jobs for the landless poor, recycles a resource otherwise being wasted and improves the availability of fertilizer,” he said.
The product could represent a potential breakthrough for Ethiopia and the continent, said Learned Dees, cultural affairs officer at the U.S. Embassy in Addis Ababa.
“We need to think more creatively about how to put the waste streams we generate to good use,” Lehmann said. “Nothing should be off limits.”