Crop yields in sub-Saharan Africa have barely risen over the past 30 years,yet the population has more than doubled. The result has been widespread malnutrition and persistent poverty, especially in rural areas. According to Saving Africa’s Soils: Science and Technology for Improved Soil Management in Africa, the continent’s degraded soils, and the lack of investments in adequate soil management, are undermining the ability of African farmers to increase crop yields and bring about an era of greater food security.

Commissioned by the secretariat of the New Partnership for Africa’s Development (NEPAD), Saving Africa’s Soils was compiled by the World Agroforestry Centre and the Tropical Soil Biology and Fertility Institute of the International Centre for Tropical Agriculture (CIAT). It draws on a series of sub-regional reports by soil scientists, based on interviews with professionals in East and Central Africa, Southern Africa, the West African humid tropics and the Sahel. The final report reflected the discussions at a Round Table of Experts, convened by the World Agroforestry Centre in Nairobi. The Round Table charted a way forward for soil science research in Africa, highlighting the main elements needed to support sustained agricultural production and environmental protection.

 According to Keith Shepherd, co-author of the report and lead soil scientist at the World Agroforestry Centre, knowledge of Africa’s soils is limited. “Basic soil surveys conducted in the 1950s and 1970s mapped broad boundaries for different soil types, but these were very crude, and the surveys failed to take into account the huge variability in soil types locally,” he says. “The lack of good information, and the fact that there is no systematic data system monitoring soil health, has held back well-planned agricultural development.”

However, there have been considerable technological advances in recent years, and these should enable scientists – and government agencies – to survey and assess soil health relatively quickly and cheaply in future. Saving Africa’s Soils identified problem diagnosis and impact assessment, using the latest technologies, as one of the four key areas of research that could make a major contribution to improving soil health and raising productivity. The report also stresses the importance of research on integrated soil fertility management, which combines the use of organic and inorganic fertilizers. Integrated soil fertility management recognizes that nutrients and water cycles are inextricably linked, and together determine a soil’s ability to sustain crops and provide essential environmental services. Science has a key role to play in researching and promoting integrated soil fertility management, but the report recognizes that much more research needs to be done on how to increase the rate of adoption of good management practices.

Although sub-Saharan Africa is heavily reliant on agriculture for economic growth, public spending on farming amounts to just four per cent of total government spending. The lack of investment has meant that many soil laboratories have closed, admissions to soil science and agricultural university courses have fallen dramatically and many universities’ soil science curricula are seriously out of date. Bucking these trends will be essential if Africa’s soils are to be better managed.

The research agenda proposed by Saving Africa’s Soils implies the reorientation of conventional approaches to soil science, with a much stronger emphasis on interdisciplinary thinking, and the updating of Africa’s soil laboratories All of this will require a significant increase in investment, both by national governments and donors. As the authors of the report point out, “The future livelihoods of the world’s poorest people depend on the development and widespread adoption of practices aimed at restoring and sustaining the productivity and ecosystems service functions of Africa’s soils.”

The need to establish a diagnostic surveillance framework to improve the management of farmland is discussed in greater detail in a paper written by Keith Shepherd and Markus Walsh, and published in the Journal of Near Infrared Spectroscopy. Walsh and Shepherd have been developing the concept of ‘soil health surveillance,’ modelled on medical diagnosis approaches, for many years. The use of infrared spectroscopy, which provides a cheap and rapid means of analysing the health of soils, plants, livestock and water resources, would be an integral part of such a system. “A soil health surveillance system would benefit a whole range of users, from agricultural extension workers and smallholder farmers to the fertilizer industry, regional development programmes and international donors,” says Shepherd. The World Agroforestry Centre and the United Nations Environment Programme (UNEP) are using the soil health surveillance approach in West Africa to identify soil constraints to food production and opportunities for sequestrating carbon.

The New Partnership for Africa’s Development (NEPAD) has just signed a cooperative agreement with the African Network for Soil Biology and Fertility (AFNET), the World Agroforestry Centre and CIAT’s Tropical Soil Biology and Fertility Institute to jointly develop a programme to build African research and educational capacity in stateof- the-art concepts and methods in soil science. The emphasis will be on soil health surveillance and integrated soil fertility management through the establishment of virtual ‘centres of excellence.’ The group is also working with the Bill and Melinda Gates Foundation and the Alliance for a Green Revolution in Africa (AGRA) to help develop complimentary initiatives to save Africa’s soils and boost agricultural productivity.

Further reading
anagement in Africa. Nairobi: World Agroforestry Centre.
http://worldagroforestry.org/Library/listdetails.asp?id=49775

Shepherd KD, Walsh MD. 2007. Infrared spectroscopy – enabling an evidence-based diagnostic surveillance approach to agricultural and environmental management in developing countries. Journal of Near Infrared Spectroscopy. 15, 1-19.
http://worldagroforestry.org/Library/listdetails.asp?id=49200

For more information,
contact Keith Shepherd,
k.shepherd@cgiar.org