Bambara Ground-What?

Throughout Africa and Asia, small-scale farmers have been quietly tending to this crop for generations, yet most have never heard of it. It’s highly nutritious, ready for a changing climate, and good for the soil–and it fetches a high price in local markets–yet it’s not grown on nearly the scale of crops like maize or wheat.

In sub-Saharan Africa, it’s mostly grown by women. In Indonesia, farmers cultivate it in small quantities while closely monitoring how well it holds up to local crop diseases. There is a widespread belief that this largely invisible crop holds great commercial potential, yet there are no commercial varieties. Maybe it’s time for that to change; at least that’s what the CSIR-Savanna Agriculture Research Institute in Ghana, one of Grow Further’s first grantees, believes.

If you go to any grocery store in the West and ask the staff to point you to the Bambara groundnut section, they are very unlikely to know what the heck you’re talking about. In West Africa, they might, but they are equally unlikely to be selling this produce.

Bambara groundnuts are chickpea-like legumes. The plant is native to the Sahel, the semiarid region separating tropical Africa from the Sahara Desert, and named for the Bambara people, thought to be the first to cultivate it. The Sahel is a difficult place to grow food, so the Bambara groundnut has evolved (via both nature and human hands) to be one strong little plant.

A tough nut to crack

Having arisen from the Sahel, the Bambara groundnut is famously drought-resistant. The plant is also a bit difficult to describe, and the beans come in a wide variety of shapes and sizes. One team of researchers describes the plant as “bunched leaves arising from branched stems, which form a crown on the soil surface.” A.S. Gerrano et al. goes on to complain that the Bambara groundnut’s physical properties make it hard to study.

“After self-fertilization, pale yellow flowers are borne on the soil freely growing branching stems; these stems then grow downwards into the soil, taking the developing seed within the pods, which makes breeding and development of new cultivars for the traits of interest difficult.” In other words, agricultural researchers can’t visibly monitor the progress of growth since, like the peanut, Bambara groundnut seeds grow underground encased in hard pods. Visible inspection means digging them up and cracking them open, killing the plant.

We need to more fully understand this underutilized crop before it can become a commercial success. Like other legumes, Bambara groundnuts are nitrogen-fixing plants—while most crops pull critical nitrogen out of soils to grow, Bambara groundnuts take nitrogen out of the atmosphere and put it back into the ground. A joint study by the United Kingdom non-profit Crops for the Future and Nottingham University argues that agriculture authorities in China should take the Bambara groundnut seriously precisely for its nitrogen-fixing properties; this Sahelian native could be one means for Beijing to address its food security concerns.

“The crop has yield potential in areas that can be too marginal for production of other mainstream crops such as soybean,” the study, published in Food and Energy Security, says. “If realized, the potential of Bambara groundnut could contribute to China’s agriculture and reduce its reliance on vegetable protein imports.” They also see the plant promoting better soil health in China via intercropping or crop rotation. Other research has discovered that Bambara groundnuts contribute to the accumulation of biofertilizers in soils.

Thus, what science knows today is that this neglected, overlooked crop is good for people and good for the soil. As the two UK research organizations note, Bambara groundnuts are rich in protein and fiber. Researchers at Nigeria’s Federal Polytechnic Oko say blending Bambara groundnut flour with cassava flour yields the ultimate nutrition-fortified biscuits.

On the case

Many mysteries involving the Bambara groundnut have yet to be cracked open. For instance, it is not yet fully understood why this little legume is so tough. “Bambara groundnut has been observed to resist pest and drought, and still able to produce enormous yield when cultivated on poor soil,” as Ajilogba et al. point out in a preprint. It probably has something to do with the microbiome that Bambara groundnut plants produce in soils, they suggest. Whatever the cause, the CSIR-Savanna Agriculture Research Institute is determined to develop a successful commercial variety capable of lifting the Bambara groundnut out of its obscurity.

Researchers at CSIR-SARI have begun studying this crop and have identified about 100 distinct accessions. They’ve identified multiple traits affecting yield potential, as well as huge diversity in other traits that may be at least as important to farmers. As participatory plant breeding, their project funded by Grow Further starts with understanding what farmers want and works with them throughout the breeding and commercialization process. Some traits that the final release may prioritize include drought tolerance, the ability to mature in a short season, and suitability for cooking or processing into milk.

Western shoppers may have a tough time finding this legume in their grocery store aisles today. But Bambara groundnut milk is available online from a Singapore-based startup, and in stores in a few countries. And the raw beans could become popular around the world as well. Whatever the future holds for this chickpea-like crop, we at Grow Further are proud to be partnering with CSIR-SARI on its development.

 — Grow Further

Photo credit: Bambara groundnut variety samples at the CSIR-Savanna Agricultural Research Institute Manga Field Station. Kwekwe Photography.

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