The nature of agriculture is changing. Farmers across the world struggle to produce more food while facing changing rainfall patterns, a warmer world, and increased competition over land and water. Ecosystem degradation, declining soil fertility, and water stress add to these land use pressures.
Nowhere are these challenges more severe than in sub-Saharan Africa’s drylands. Farmers in dryland regions like the Sahel must grapple with drought, unpredictable rainfall, and depletion of soil nutrients. At the same time, sub-Saharan Africa is one of world’s poorest regions. Roughly 200 million people—a full 27 percent of the population—are undernourished. Forty percent of children under the age of five are stunted due to malnutrition.
What Is Conservation Agriculture?
In response to continued land degradation, a set of techniques designed to improve soil fertility and water use efficiency has become widespread, particularly on large commercial farms. These techniques, together referred to as “conservation agriculture,” are based on three linked practices:
- Minimal soil disturbance by reducing the amount of tillage or adopting “no-tillage” techniques
- Retention of crop residues or maintenance of a cover crop
- Crop rotation or diversification of crop species grown in sequence and/or associations.
Conservation agriculture is among a group of practices that provide a “triple win” of increased agricultural productivity, enhanced resilience to climate change, and sequestration of carbon.
But while the challenge is great, so is the opportunity. Innovative farmers have demonstrated how agroforestry and other relatively simple practices can significantly boost food production in Africa’s drylands. In fact, according to a new WRI working paper, improving land and water management on just 25 percent of sub-Saharan Africa’s 300 million hectares of prime cropland would result in an additional 22 million tons of food. This strategy could go a long way towards sustainably feeding Africa—and the world.
Farming in Africa’s Drylands
Sub-Saharan African farmers have been fighting drought and land degradation for years. In response, a growing number are starting to adopt improved land and water management practices to reduce erosion, capture more rainfall, increase soil organic matter, and replenish nutrients. Their encouraging results provide lessons in the types of strategies needed to restore the productivity of cropland and produce enough food for a growing population. Improved land and water management practices such as agroforestry, conservation agriculture, rainwater harvesting, and integrated soil fertility management are sustainably increasing crop yields while also reducing agriculture’s impact on the environment.
- Farmers in Burkina Faso and Niger are using water-harvesting techniques such as building stone lines and improved planting pits (locally known as zai). These practices help to trap rainfall on crop fields, increasing average cereal yields from 400 to 900 kilograms per hectare (kg/ha) or more. Applying small quantities of fertilizer directly to seeded crops or young shoots early in the rainy season can complement these low-tech land and water management techniques. Combining this “micro-dosing” with practices like water-harvesting has increased millet and sorghum yields from fewer than 500 kg/ha to 1,000 or 1,500 kg/ha.
- Farmers in Malawi are planting Faidherbia albida trees on fields using modest amounts of fertilizer. These trees provide canopies of shade and lock nitrogen in the soil. Farmers have seen their maize crop yields increase from fewer than 2 tons per hectare to 3 and 4 tons per hectare . Yields are more than 7 tons per hectare when these conservation agriculture practices are combined with agroforestry, fertilization, and other strategies.
- In West Africa, farmers are employing integrated soil fertility management by applying crop resides, compost, mulch, livestock manure, leaves, and fertilizer. These practices help farmers meet the nutrient needs of the crop while restoring soil organic matter and overall soil fertility, which contributes to sustainable intensification of crop production. Integrated soil fertility management across more than 200,000 hectares resulted in crop yield increases of 33-58 percent over a four-year period. Farmers also saw revenue increases of 179 percent from maize and 50 percent from cassava and cowpea.
More Action Is Needed
Despite the benefits of improved land and water management and some major successes, overall adoption of these strategies remains too limited to make a significant impact on Africa’s food security. Some of the commonly cited barriers include a lack of awareness of the appropriate practices and their benefits, as well as low levels of investment in knowledge dissemination. Agriculture projects run by governments, NGOs, and others often fail to engage with farmers or effectively spread the word about how to accomplish rainwater harvesting, agroforestry, and other practices. Countless farmers are not reached by agricultural extension agents at all—where extension does exist, agroforestry, conservation agriculture, and other practices are insufficiently integrated. And in many cases, national policies and legislation do not provide sufficient incentives—such as giving citizens legal ownership of their land and clear rights to manage on-farm trees—to encourage farmers to invest in improved land and water management.
Additionally, many decision-makers tend to focus on more “high-tech” solutions to increasing food production—strategies like increased subsidies for mineral fertilizers, promotion of improved seeds, and agricultural mechanization. But the potential benefits of these approaches will be undermined unless the depletion of soil fertility is reversed and climate change impacts are overcome.
A growing number of farmers in Africa’s drylands are already showing us the benefits of improved soil and water management. Now it’s time to scale up these practices to make widespread, significant, and sustained gains in crop yields.