Ways and means to increase the biological nitrogen fixation and productivity of grain legumes to contribute in enhancing soil fertility, improve household nutrition, and increase cash income of smallholder farmers in Africa were explored at the inception workshop of N2Africa-Ethiopian Program. The workshop was held on 27-28 February, at the International Livestock Research Institute (ILRI) campus in Ethiopia.

N2Africa is a science-based ‘research-in-development’ project focusing on putting nitrogen fixation to work for smallholder farmers growing legume crops in Africa.  Chickpea, which is ICRISAT’s mandate crop in the N2Africa-Ethiopia, has a high potential to fix atmospheric nitrogen. It is estimated that 50% nitrogen fixed by chickpea remains in the soil and is available to the next crop. The crop is also sensitive to drought during flowering and pod-set stages. Symbiotic fixation of nitrogen is also drought sensitive. The interactions between chickpea and indigenous Rhizobia genotypes with the environment are the current subjects of the study.

In its first phase, N2Africa reached more than 230,000 farmers who evaluated and employed improved grain legume varieties, rhizobium inoculants and phosphate-based fertilizers. In the second phase, the focus remains on research and dissemination of major grain legumes in selected areas in the core countries – Ghana, Nigeria, Ethiopia, Tanzania and Uganda. Its activities will focus on cowpea, groundnut and soybean in Ghana and Nigeria; on common bean, cowpea, groundnut and soybean in Tanzania and Uganda; and on common bean, soybean, chickpea and faba bean in Ethiopia.

Nitrogen is one of the most limiting macro-nutrients for crop growth. Legume plants have formed symbiotic relationship with the bacteria called Rhizobia within nodules in their root systems, producing nitrogen compounds that help the plant to grow and compete with other plants.

When the legume plant dies, fixed nitrogen is released, making it available to other plants and this helps to fertilize the soil. The fixation process, which releases nitrogen to the rhizosphere, is essential not only for plant growth but also for improving human and livestock nutrition and reducing the amount of chemical fertilizer and minimizing costs of production for farmers.

However, for plants to fix nitrogen there is a need to inoculate legume seeds with compatible Rhizobia, which are often not naturally occurring in most of the soils. Production of efficient inoculants and distribution to smallholder farmers is a limitation, and is the thrust of N2Africa which contributes to the impact pathways of the product line 4 of the CGIAR Research Program on Grain Legumes.

With funding from the Bill & Melinda Gates Foundation, N2Africa began the second phase on 1 January. The project will run for five years and is led by the Wageningen University together with the International Institute of Tropical Agriculture (IITA), ILRI, and ICRISAT.

ICRISAT is actively involved in N2Africa through the product line 4 of the CGIAR Research Program on Grain Legumes which deals with biological nitrogen fixation, and through the Tropical Legumes project which breeds and supplies most of the varieties and lines used as test crops in the project.

Representing ICRISAT at the workshop, Drs Tilahun Amede, Principal Scientist (Natural Resources/Systems Agronomy) and Chris Ojiewo, Senior Scientist (Legumes Breeding) actively took part in presentations emphasizing the importance of nitrogen fixation.

Adapted from ICRISAT Happenings