This post originally appeared on the International Food Policy Research Institute blog and was written by Claudia Ringler, Deputy Director of IFPRI's Environment and Production Technology Division (EPTD) and co-leader of the CGIAR Research Program on Water, Land and Ecosystems (WLE) flagship program on Variability, Risks and Competing Uses. 

Can Sub-Saharan Africa feed itself? This is a question that has been asked for decades but no satisfying answer has yet been found and is unlikely to be found in the near to medium-term future. Why?

The region is adding more than one billion people over the next 30 years, in just over a single generation. Most of the added population will reside in urban areas and demand more access to dairy and meat products, as well as to cereals, vegetables and fruits, fats, oils and sugars than did the previous generation, which resided largely in rural areas.

This projected increase is juxtaposed with continued low agricultural productivity compared to the rest of the world. Cereal yields in 2016 (centered three-year average across 2015-2017) averaged 1.5 tons per hectare in Sub-Saharan Africa, compared with 7.2 tons in North America, 4.8 tons in South America and 4.1 tons across Asia. While recent growth in Africa has been remarkable—1.8 percent per year—at that rate it would still take the region 55 years to achieve today’s average cereal yield in Asia. The region also faces the largest inter-annual variability in precipitation, while climate change is already affecting the onset and volume of precipitation.

Combined with civil strife and unrest in various parts of the region, food insecurity has been climbing over the last several years. The number of undernourished people in Sub-Saharan Africa rose from 181 million in 2010 to almost 222 million in 2016, according to the latest UN reports on Food Security and Nutrition—an increase of 23 percent in six years. Current projections show the number may have increased to more than 236 million by 2017.

This adverse trend is wiping out much of the progress that has been made over the last decade.

So it is not surprising that a 2016 study found that for countries in the region to maintain current food self-sufficiency levels of around 80 percent, they would need to “radically” accelerate rates of yield improvement—or massively expand land areas (with associated greenhouse gas emissions and biodiversity loss), or increasingly resort to food import dependency.

A new IFPRI study published in Water International focuses on the potential of irrigation in providing food security for Sub-Saharan Africa's growing population. The study used an integrated biophysical and economic modelling approach to assess quantitatively the irrigation development potential in Africa and linked the prospective investment with changes in food security and food import dependency. The study focused on drylands, which cover 70 percent of the region’s cropland, are home to half its population and are also where hunger and malnutrition are most prevalent and crop production most fragile.

The study identifies sustainable and profitable irrigated area growth of three percent per year across the region, with fastest growth occurring in Central Africa, balancing slower growth in Eastern Africa. Across dryland regions, the study shows, the potential for irrigation expansion is largest in West Africa, which accounts for about 50 percent of the irrigation potential in dryland areas in Sub-Saharan Africa. This is followed by Eastern and Southern Africa, each with more than 20 percent of total potential. The potential in Central Africa is smallest because this sub-region has limited dryland areas. For individual countries, the potential is largest in Nigeria, followed by Tanzania, Kenya and Malawi. Across the region’s dryland areas, up to 14 million hectares could sustainably and profitably be converted into irrigated areas.

For all irrigation expansion scenarios in African drylands, net cereal imports to the region decline, with decreases reaching as much as 68 percent, or 90 million tons, from a baseline net import volume of 133 million metric tons in 2050. The dramatic production increases achieved under the accelerated irrigation scenarios can thus drastically reverse the region’s growing net food import dependency ration. Specifically, targeted investments in irrigation in the dryland areas can effectively reduce growing food import dependency from 54 percent under a business-as-usual scenario to levels below today’s. The resulting national economic growth and rural income gains could also substantially reduce the region’s population at risk of hunger, above and beyond the reductions from increased access due to lower food prices from accelerated growth.

Achieving these impressive results for food production and food self-sufficiency will require declines in irrigation technology costs; greater availability and accessibility to complementary rural infrastructure such as roads, storage and credit; and access to complementary agricultural inputs in dryland areas. The recent Malabo Montpellier report on Water-Wise Irrigation sums up the way forward:

1. Elevate irrigation to a top policy priority;
2. Develop “smart regulations” to avoid degradation and pollution from irrigation development;
3. Continually innovate with irrigation technologies;
4. Invest in support infrastructure; and
5. Explore innovative partnership and financing models to support development and growth of the sector.

If Sub-Saharan Africa is to feed its growing population over the coming decades, sustainable drylands irrigation will be essential. The time to make irrigation both a national and regional priority is now.