The common bean (Phaseolus vulgaris L.) is a key crop in the Rwamwanja refugee settlement in Southwest Uganda. It serves both as a staple food and an important source of income for refugees and the host community alike. According to the National Agricultural Advisory Services (NAADS), beans contribute to a national per capita consumption rate of 58 kg.
Despite its importance, bean production faces serious challenges. The average yield in Rwamwanja is only 300 kg per acre, far below the national expected yield of 1,300 kg.
Production systems are predominantly small-scale, with 95% of farmers cultivating less than 0.5 acres and achieving an average yield of just 0.15 metric tons (150 kg). These figures stand in stark contrast to the national potential yield of 350 to 650 kg per 0.5 acres, depending on the bean variety. Low input use, particularly seeds and pesticides, exacerbates the problem, as most refugees rely on seeds saved from previous harvests.
Introducing Rhizobia Inoculants: A Game-Changing Solution
To address these challenges, HealthyFoodAfrica project’s Food System Lab Rwamwanja, operated by Finn Church Aid, introduced rhizobia inoculants as a sustainable solution.
Rhizobia inoculants are living bio-fertilizers that enhance nitrogen release—a crucial nutrient for plant growth—through symbiotic relationships with legume roots. Unlike inorganic fertilizers, rhizobia pose no health risks, are affordable, and remain active in the soil for multiple seasons.
As part of its initiative, the Food System Lab tested the effectiveness of Mak-Bio-Fixer rhizobia inoculants using two approaches. The inoculants were distributed to 50 pilot farmers—40 women and 10 men—who applied them independently. In addition, a demonstration plot was cultivated with rhizobia by the Food System Lab technical team in collaboration with farmers at a cooperative facility. A control plot without rhizobia served as a basis for comparison.
The results were transformative. “Farmers using rhizobia inoculants on their individual fields recorded an average yield increase of 38%, while the cooperative demonstration plot saw a remarkable 47% yield boost compared to the control plot. These figures underscore the potential of rhizobia to revolutionize bean farming and improve household food security,” says Frank Tukamuhebwa, the Agriculture Extension Officer at Finn Church Aid.
Eco-Friendly and Cost-Effective Farming
Rhizobia inoculants are not only farmer-friendly but also environmentally sustainable. Chemical fertilizers, which cost about $60 per 50-kg bag, can degrade soil quality. In contrast, just 100 grams of rhizobia—costing only $1—are sufficient to fertilize an entire acre of beans.
Moreover, rhizobia reduce dependence on chemical fertilizers, which pollute water and threaten biodiversity. These bio-fertilizers offer a cost-effective and eco-conscious solution for smallholder farmers, while also preserving soil health for future cultivation.
Improved Nutrition and Income
Enhanced bean yields have brought tangible benefits to refugees in Rwamwanja. Beans are consumed at various growth stages—tender leaves, green pods, fresh seeds, and dried seeds—making them a versatile crop for food security. With a short growing cycle of 60–76 days, beans mature more quickly than maize, which requires up to 115 days.
Financially, beans also offer strong returns. In some seasons, they even surpass maize as the top income-generating crop, particularly during short rainy periods.
Beans also contribute to soil conservation by providing ground cover that reduces erosion from wind and rain. This encourages intercropping with maize, as beans suppress weeds and improve soil fertility through nitrogen fixation, further boosting yields.
Voices from the Field
Marion Komugisha, Vice Chairperson of the Rwamwanja Rural Farmers’ Cooperative, shared her experience: “Immediately after Finn Church Aid and professors from Makerere University trained us on how to use ‘living fertilizer’, I applied it to my ¼-acre plot. The beans grew greener and healthier, even under dry conditions. I harvested 89 kg compared to my usual 60 kg—a significant improvement.”
Elinelda Mukundatuyine, a refugee widow from Nkoma zone, praised the organic nature of rhizobia, which allowed her to harvest tender bean leaves during a drought.
“My inoculated plot yielded 84 kg, while the untreated one produced only 61 kg. I didn’t need to reapply the inoculant in the next season—it remained in the soil and improved yields even further. I hope to get similar fertilizers for maize to support year-round food security.”
Through the introduction of rhizobia inoculants, the Food System Lab has helped farmers overcome key production barriers and improve food security within the settlement. By bridging scientific innovation and practical farming, this initiative demonstrates the powerful impact of bio-fertilizers on sustainable agriculture—and offers a replicable model for other vulnerable communities.