A key reason is that these farmers don't have enough land and can't afford livestock to fertilize their fields...
A key reason is that these farmers don’t have enough land and can’t afford livestock to fertilize their fields. They are caught in a classic poverty trap. To produce food to eat and sell, they must farm their meager plots intensively, which strips the soil of nutrients. That produces lower yields, which leaves farmers too poor to improve their land.
To help break that vicious cycle, Giller is harnessing the power of legumes. Beans, cowpea, chickpea, soybean, and others enrich the soil with life-giving nitrogen. Bacteria that live in nodules along the plant’s roots are able to transform the nitrogen in the air into the organic form plants need to grow. I caught up with him recently and asked him to explain.
What started your love affair with legumes?
For me, it’s one of the most wonderful results of evolution. It’s incredible that bacteria learned to associate themselves with legume plants in a way that they can grow independently of mineral nitrogen, compared to all other plants and crops.
How do legumes improve the lives of farmers?
They have different amino acids and provide a range of different minerals that you don’t find in other crops. The nitrogen being captured from the air is basically put directly into protein, so they’re protein-dense foods. Peanuts and soybeans are also oil rich, so they’re very good energy sources. When farmers grow legumes in rotation with other crops, or in between their other crops, we find the maize and other cereals grow better.
How do you introduce legumes and different farming practices to the farmers?
In the different communities where we work, we’re holding village field days to attract interest. We’re discussing with farmers what their needs are. We then go back and set up demonstration plots with the newer varieties [of crops] and different cultivation techniques close to schools and village centers. They’re in a very public place where they get seen by a lot of people. Sometimes we give farmers little packs of seeds and inoculant and phosphorus, just enough for a little garden plot. But it allows them to see whether they work for them.
What’s an example of different cultivation techniques?
Row planting, intercropping—mixing—or rotation. With climbing beans … putting in stakes that actually form a tripod. Often very simple things can have big impacts in terms of yields and productivity.
When you’re teaching farmers, how do you incorporate their knowledge into your work?
Their understanding of their soils and their climate can be really important. We actually look toward farmers to not only adopt what we’re suggesting, but very much to adapt it. If people are adapting things to fit their own purposes, it means they’re blending them into their own systems.
What’s an example of this kind of adaptation?
Because [many farmers] have a shortage of wooden stakes, they use maize stalks, particularly with the climbing beans. You see all sorts of different approaches like that.
How do farmers use the inoculant?
The inoculant has Rhizobium—a bacterium that helps the legumes fix nitrogen. The farmers put it in a bucket with the seed and shake the bucket. That coats the seed and carries the bacterium with it into the soil.
How do you start working in a new village?
We engage with farmers who have natural talent for leadership. They get extra training, and then work with and train others… They become these self-reinforcing groups.
Can you tell me about a favorite farmer you’ve met?
One would be a farmer in Musanze district, northern Rwanda—a lady called Mrs. Gasilida Nyirabarenzi. She was the first person in her area to try a climbing bean variety that has her name: “Gasilida.” So she’s quite famous. And she’s an important farmer, because she tends to demonstrate things to neighbors.
You also experiment with using different fertilizers. Why?
We know legumes can fix nitrogen, but they need phosphorus. Because these soils in Africa are very old soils, they’re often depleted in many different nutrients. So we’ve been working with different fertilizer companies to identify these deficiencies in different regions.
