Africa's soils are under threat, especially due to climate change. But improved practices that conserve and maintain soils for future food and nutrition needs are taking root.
Leaders in the agricultural sector from across Africa gathered to support the movement From Science to Action on 13 November 2016, at an event scheduled in collaboration with the Government of Morocco's "Adaptation of African Agriculture" or "AAA" initiative at the UN Climate Talks in Marrakech. The "AAA" founders identified sustainable and resilient soil management as a fundamental element in food system and one of three areas requiring immediate action.
“Nutrient and soil organic matter depletion and soil erosion worsen the effect of climate change and decrease farmer resilience,” Rob Bertram, Chief Scientist for the United States Agency for International Development (USAID) Bureau of Food Security, explained in the plenary session of the event. “We have to increase crop productivity in Africa, or else agricultural expansion is just spreading poverty.”
Dr. Rachid Mrabet, research director of the National Institute for Agricultural Research (INRA) of Morocco, pointed out key threats to soil in Africa, including erosion, loss of soil organic carbon, and nutrient inbalance. “We need to go from the degradation spiral to the sustainability spiral,” he said.
Professor Tekalign Mamo, laureate of the 2016 IFA Norman Borlaug Award, distinguished soil scientist and former Ethiopian State Minister of Agriculture, sought to emphasize that soil is at the base of our agricultural system and is not to be overlooked in a sessions focused in soils. He said, “Soil is a non-renewable resource that is facing danger of extinction.”
Soil maps of Africa: One cannot manage what is not measured
Professor Mamo explained the extensive EthioSIS research initiative undertaken in Ethiopia – including over 100,000 samples, the critical utilization of the data to examine the full range of options, and how the government of Ethiopia initiated public and private sector relationships that brought needed interventions to farmers.
Individual country initiatives in South Africa, Ethiopia, Nigeria, Tanzania, and Ghana, among others, are generating soil maps and related information, and multi-lateral initiatives in multiple countries and numerous private and institutional soil laboratories are complementing this information. The FAO, for example, is hosting the Global Soils Partnership and recently published a booklet Boosting Africa’s Soils.
However, critical gaps in geographical coverage and richness of data remain, limiting the provision of practical guidance to farmers on sustainable soil management practices and the accurate estimation of greenhouse gas emissions or carbon sequestration.
Soil organic carbon: Sequestration potential and sponge that holds micronutrients together
At a certain level of soil degradation, including minimal soil carbon, no amount of inputs by farmers will make the soil productive. Soil organic carbon is both critical to soil quality and has high mitigation potential, explained Professor Rattan Lal, world-renowned soil scientist from the Ohio State University.
“Soil seems to have suffered from the tragedy of the commons,” said Professor Rattan Lal. “We are using the carbon, but we’re not putting it back.”
Professor Lal called for more data on soil organic carbon in Africa and analysis and promotion of how increases in carbon could be supported, including through conservation agriculture and indigenous knowledge. FAO natural resources officer Martial Bernoux shared that FAO is working with partners to develop a global soil organic map of 2017.
Fertility: Critical to feed the continent
In certain parts of the world, fertilizer use exceeds recommendations and is causing extensive greenhouse gas emissions and reducing water quality. But not in sub-Saharan Africa, where fertilizer use is the lowest in the world. Charlotte Hebebrand, Director General of the International Fertilizer Industry Association (IFA) said that fertilizer demand from sub-Saharan Africa represented only 1.9% of global demand.
But fertility is also low in sub-Saharan Africa, and the challenge of tripling production by 2050 to feeding the growing population will require improved agronomic management, including fertilizers. A recent CCAFS policy brief: Fertilizers and low emission development in sub-Saharan Africa examines this topic in detail.
"The debate has moved on," Andrew Noble, Deputy Director General of the International Center for Agricultural Research in the Dry Areas (ICARDA) said. "Africa needs BOTH organic & mineral fertilizers, used together.”
Hebebrand suggested that Africa may be able to avoid the overuse of fertilizer by maintaining nutrient use efficiency (NUE) through conservation agriculture, site-specific nutrient management, integrated soil fertility management, flexible approaches depending on location, and the 4Rs: right source of nutrients, right rate, right time, and right place.
Increased productivity may also reduce pressures on forests and grasslands.
Here at the UN Climate Talks, as countries strategize to achieve sustainable development goals while implementing their Nationally Determined Contributions to slow climate change, investing in soil fertility is widely recognized essential. And it will pay off: Investments in climate adaptation for smallholders result in profits more than doubling, according to a new study by the UN's International Fund for Agricultural Development (IFAD).
Learn more: Recent CCAFS research on soils
Richards M, van Ittersum M, Mamo T, Stirling C, Vanlauwe B, Zougmoré R. 2016. Fertilizers and low emission development in sub-Saharan Africa. CCAFS Policy Brief no. 11. Copenhagen, Denmark: CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS).
Sanou J, Bationo BA, Barry S, Nabie LD, Bayala J, Zougmore R. 2016. Combining Soil Fertilization, Cropping Systems and Improved Varieties To Minimize Climate Risks On Farming Productivity In Northern Region Of Burkina Faso. Agriculture and Food Security 1-12.
Thierfelder C, Matemba-Mutasa R, Bunderson WT, Mutenje M, Nyagumbo I, Mupangwa W. 2016. Evaluating manual conservation agriculture systems in southern Africa. Agriculture, Ecosystems & Environment 222:112-124.
Vermeulen S, Richards M, De Pinto A, Ferrarese D, Läderach P, Lan L, Luckert M, Mazzoli E, Plant L, Rinaldi R, Stephenson J, Watkiss P. 2016. The economic advantage: assessing the value of climate change actions in agriculture. Rome, Italy: International Fund for Agricultural Development (IFAD).
Chakrabarti S. 2015. The mitigation advantage: maximizing the co-benefits of investing in smallholder adaptation initiatives. International Fund for Agricultural Development.
Richards MB, Butterbach-Bahl K, Jat ML, Lipinski B, Ortiz-Monasterio I, Sapkota T. 2015. Site-Specific Nutrient Management: Implementation guidance for policymakers and investors. Climate-Smart Agriculture Practice Brief. Copenhagen, Denmark: CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS).
Roobroeck D, van Asten P, Jama B, Harawa R, Vanlauwe B. 2015. Integrated Soil Fertility Management: Contributions of framework and practices to climate-smart agriculture. Climate-Smart Agriculture Practice Brief. Copenhagen, Denmark: CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS).
Richards M, Sapkota T, Stirling C, Thierfelder C, Verhulst N, Friedrich T, Kienzle J. 2014. Conservation agriculture: Implementation guidance for policymakers and investors. Climate-Smart Agriculture Practice Brief. CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS), Copenhagen.