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Does Africa Have A Fertilizer Gap And Can Beans Fill It?

Does Africa Have A Fertilizer Gap And Can Beans Fill It?

In parts of sub-Saharan Africa where nitrogen fertilizer is too expensive for subsistence farmers, beans are more than a source of protein. They’re an environmentally friendly fertilizer alternative that could help counteract limited fertilizer uptake, according to a SciDevNet report by Natasha Gilbert.

Legumes “fix” nitrogen into the soil in a biological process that improves soil health and the overall productivity of the farming system, according to a blog in CIAT. Unlike nitrogen fertilizers, the biological process is free.

Global use of nitrogen fertilizer is expected to increase by 1.4 percent per year through 2018, but less than 5 percent of that growth will come from Sub-Saharan Africa, according to a report published Feb. 16 by the U.N.’s Food and Agriculture Organization, SciDevNet reports.

In Africa, lack of nitrogen in the soils is the “most limiting factor” holding back agriculture on the continent, according to Rob Horsch, who leads the agricultural research and development team at the philanthropic organisation, the Bill & Melinda Gates Foundation.

Nitrogen fertilizer is not needed when growing legumes such as beans and peas, because the plants grab all the nitrogen they need from the air with the help of bacteria living in their roots, SciDevNet reports. Some of the captured nitrogen also enters the soil through fallen leaves and from decomposing roots, helping to fertilize crops that are later farmed on the land.

A Netherlands-Based project, N2Africa, is teaching African farmers how to use legumes to boost harvests of staple crops such as maize. Maize production has been stagnant at around one tonne per hectare since the 1960s, SciDevNet reports. Legumes also provide poor farmers with additional income and food.

Jeroen Huising, a CIAT scientist and N2Africa program coordinator, said, “We learned long ago that technologies to improve the soil aren’t popular because, while improving soil fertility is important, it is not a high priority for smallholder farmers. They need better yields and higher incomes this year, not in five years’ time. What is needed is a technology that is profitable to the farmer, which improves soil fertility at the same time.”

Started in 2009, N2Africa now involves more than 250,000 farmers in 13 African countries, including Rwanda and Uganda. Average legume harvests have increased by 12 percent to nearly 400 kilograms per farm, according to data published in May, SciDevNet reports. Legumes added an average of 28 kilograms of nitrogen to the soil per farm — a 169-percent increase over previous levels. Legumes helped boost average maize yields by at least 40 percent.

To ensure the long-term success of legumes, it’s essential to help develop a market so farmers can get a good price, said Bashir Jama, director of the Soil Health Program at the Alliance for a Green Revolution in Africa, an NGO working to improve food security.

Beans for fertilizer are not just for subsistence farmers in Africa, Jama said. They’re also becoming more popular in wealthy countries such as Brazil and the U.S., where they’re planted to cut down on nitrogen fertilizer use, which helps the environment and saves money.