The cost of soil erosion in sub-Saharan Africa: Why the time to act is now

Soil erosion is a silent crisis eroding Africa’s future. In sub-Saharan Africa (SSA), nearly half a billion hectares of land (494 million ha – an area larger than the entire European Union) is being degraded. The main culprit is soil erosion, stripping away vital nutrients from farmlands, threatening food production, and robbing the continent of billions of dollars every year. This document, based on the latest evidence reported in a recent policy brief, lays out the true cost of soil erosion, and what can be done to reverse it: a call for a “zero erosion campaign.”

The scale of loss caused by soil erosion in sub-Saharan Africa is alarming. Each year, farmers lose about 50 kilograms of essential nutrients—nitrogen, phosphorus, and potassium—from every hectare of land they cultivate. These nutrients are critical for plant growth and food production. When we add up these losses across the entire SSA region, it amounts to more than 9 million tons of nutrients lost every year. Replacing them with fertilizers would cost over $4 billion USD per year. But for most farmers and many governments in the SSA region, this is simply too expensive. Even when fertilizers are used, they often come with some hidden costs. For instance, their production, transportation, and application in the farms release large amounts of greenhouse gases. In fact, the emissions from fertilizer use linked to erosion are estimated to be between 28 and 59 million tons of CO₂ each year, which contributes to climate change and further damages the environment.