A quarter of the world’s tropical forest is in Africa, south of the Sahara Desert.(1) There, people use firewood for cooking, adding to the toll of trees felled by mining, logging, and clearing land for agriculture. In Africa, both population growth and forest loss are twice the world average.(2) The continent lost 14% of its forest between 1990 and 2020 (slightly more than the 13% loss for South America).(3)

 

But there is new hope for African forests. Many farmers are using “agroforestry”, also known as “evergreen agriculture.”(4) Beneficial trees are planted in cropland to maintain a green canopy and restore soils year-round. Most Africans are farmers, but 80% of them have less than five acres of land.(5) Most are too poor to buy fertilizer, and their grain yields are very low. To survive, they are forced to grow grain year after year, degrading the soil. They depend on rainwater, and suffer badly during droughts and floods, which are more frequent with global warming. But if they plant the right kind of trees, they can shield their crops from excessive heat, better retain the rainwater, and even fertilize and rebuild the soil. Africa has a nitrogen-fixing acacia tree, Faidherbia albida,(6) which conveniently goes dormant and drops its leaves just as the tropical rainy season starts. Its leaves regrow at the end of the rains. Farmers plant their crops under the trees just before the rains, and the plants then grow without having to compete for nutrition with the dormant trees.

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At the end of the rains, the trees, having held back the rainwater with their roots, come to life and shade the maturing crops until they can be harvested. These plants yield grain at triple the usual amounts, and need no added fertilizer.(7) And the soils are saved from caking and erosion. As the tree canopies expand, the farmers thin the trees and sell them for timber and wood. That means more farm income. And the downed wood eases the burden of women who have the traditional task of gathering firewood, sometimes carrying it for miles.

 

Evergreen agriculture has been adopted by more than 300,000 maize (corn) farmers in Zambia and Malawi.(8) It is also spreading in the Sahel, the belt of Africa just below the Saharan desert, where millet and sorghum are the main crops.(9) Niger and Burkina Faso benefit especially, spreading evergreen agriculture to 5 million acres of land.(10) These successes are encouraging other countries to adopt evergreen agriculture.

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References

1. Rhett A. Butler, “World Rainforest Day: The World’s Great Rainforests,” Mongabay, June 22, 2020.

2. Martina Igini, “Deforestation in Africa: Causes, Effects, and Solutions,” Earth.org, March 24, 2022.

3. Niccolo Conte, “Mapped: 30 Years of Deforestation and Forest Growth, by Country,” Decarbonization Channel, November 6, 2022.

4. Héloïse Tschora and Francesco Cherubini, “Co-benefits and Trade-offs of Agroforestry for Climate Change Mitigation and Other Sustainability Goals in West Africa,” Global Ecology and Conservation 22 (June 1, 2020): e00919.

5. Steve Wiggins and Sharada Keats, “Leaping and Learning: Linking Smallholders to Markets,” ODI, May 29, 2013. 

6. Jonathan D. Haskett, Belay Simane, and Caitlin Smith, “Energy and Climate Change Mitigation Benefits of Faidherbia Albida Agroforestry in Ethiopia,” Frontiers in Environmental Science 7 (November 1, 2019): 146.

7. Jerry D. Glover, John P. Reganold, and Cindy M. Cox, “Plant Perennials to Save Africa’s Soils,” Nature 489 (September 19, 2012): 359–61.

8. “Southern Africa,” EverGreen Agriculture Partnership.

9. Chris Reij, Gray Tappan, and Melinda Smale, “Re-Greening the Sahel: Farmer-led innovation in Burkina Faso and Niger,” in “Millions Fed: Proven successes in agricultural development,” 2009, Spielman, David J.; Pandya-Lorch, Rajul (Eds.). Chapter 7, p. 53–58, Washington, D.C.: International Food Policy Research Institute (IFPRI).

10. “Niger’s Re-greening Revolution,” World Agroforestry, July 16, 2013.