Soil phosphorus deficits and trade exacerbate African food shortage

Abstract

Phosphorus (P) is a critical nutrient for food production and population growth, particularly in regions with malnutrition such as Africa. This study estimated P flows across 53 countries in Africa from 2000 to 2020, aiming to understand the historical impacts of P on the African food system. Africa is endowed with substantial P resources, having extracted 125 Mt of P from phosphate rocks between 2000 and 2020, with Morocco accounting for 64% of this total. Despite 79 Mt of P in Africa being exported in terms of either rocks or fertilizers, only 3% of P produced within Africa was traded between African countries during this period. Additionally, 12 Mt of P were utilized for agricultural production. Intensive agricultural practices and inadequate P chemical fertilizer inputs have exacerbated soil P depletion in agricultural land in some African countries, especially Ethiopia. Nearly 20% of the food P is imported from other continents, which indicates a supply-chain P trade tendency of exporting from Africa as low-value rocks and then importing as downstream high-value food. Scenario analyses for the year 2050 suggest that while P demand can be decreased 492 kt through a combination of reducing food loss fraction and improving diet management, only increasing fertilizer P input could eliminate the African future P demand. Therefore, this study highlights the need for closer cooperation among African countries to improve local use of P resources and eliminate hunger within the continent.