Evans School Policy Analysis & Research Group (EPAR)

Lack of nitrogen (N) is often cited as the most limiting factor in agriculture. Although N composes nearly 80% of the atmosphere, plants are unable to use this form of the element (N²) because of the strong triple bonds between the two atoms. Nitrogen deficiency is especially problematic in the soils of Sub-Saharan Africa (SSA). Low levels of N and other soil fertility problems have severe poverty, malnutrition and environmental degradation consequences for SSA. The process by which atmospheric N² is converted into N compounds that can be used by living things is called nitrogen fixation. Biological nitrogen fixation (BNF or biofixation) offers an alternative or additional means to traditional nitrogen fixation to increase plant-available nitrogen. Through a symbiotic relationship, an N-fixing bacterium infects a plant (usually a legume) and forms nodules on the roots of the plant in which N fixation occurs. This literature review examines the expansion and benefits of BNF, the constraints to BNF adoption, BNF regulations, and success stories of developing and distributing BNF technologies worldwide. BNF technology can be an efficient and effective tool for decreasing environmental degradation and increasing soil fertility, yields, income, and food security in SSA, although many constraints to farmer adoption exist.