Plant beans to fertilize the soil

Photo credit: SciDevNet

Image credit: Robin Hammond / Panos

  • Beans could help fill Africa’s fertiliser gap

    Speed read

    • Sub-Saharan Africa sees low amounts of nitrogen fertiliser use, which results in low yields
    • The N2Africa project backs the cheaper option of growing nitrogen-fixing beans
    • This has helped to raise average maize yields by at least 40 per cent
    Growing beans -
    Growing beans –

    An ongoing project that encourages African farmers to plant beans as food and fertiliser could help counteract the impact of limited fertiliser take-up across the continent as highlighted in a recent report.

    Global use of nitrogen fertiliser is forecast to grow by 1.4 per cent each year to above 119 million tonnes in 2018, according to a report published last week (16 February) by the UN’s Food and Agriculture Organization (FAO).

    But less than five per cent of that growth will come from Sub-Saharan Africa, largely because fertiliser is often too expensive for subsistence farmers, it says.

    The lack of nitrogen in Africa’s soils is the “most limiting factor” holding back agriculture on the continent, says Rob Horsch, who leads the agricultural research and development team at philanthropic organisation the Bill & Melinda Gates Foundation.

    As an alternative to fertiliser, Africa’s meagre crop yields are getting a boost from an edible and more environmentally friendly source instead: beans.

    When growing legumes such as beans and peas, nitrogen fertiliser is not required because the plants grab all the nitrogen they need from the air with the help of bacteria living in their roots. Some of the captured nitrogen also enters the soil through fallen leaves and from decomposing roots. This helps to fertilise crops that are later farmed on the land.

    Read the full article: SciDevNet

Author: Willem Van Cotthem

Honorary Professor of Botany, University of Ghent (Belgium). Scientific Consultant for Desertification and Sustainable Development.