In aggregate its farmers are growing more cereals, such as maize (corn) and rice, than ever: nearly five times as much as in the 1960s, when many countries achieved independence. But most of those gains came from cultivating more land, which cannot go on for ever (see chart 1). Africa, once sparsely populated, is getting crowded. The amount of arable land per person has been falling for decades, and now sits at roughly the global average.

That might not matter if farmers were also growing more crops per hectare. But recently gentle growth in agricultural productivity has given way to stagnation, perhaps even decline. Consider figures drawn from national statistics in Africa by the Food and Agriculture Organisation (FAO), a UN  body. Cereal yields did not grow between 2020 and 2024, the latest data point (see chart 2). Nor did total factor productivity (TFP), a measure of how efficiently inputs of all kinds (such as labour and machinery) are turned into produce. Most African countries had lower agricultural TFP in 2023 than a decade before.

This seems to be more than a pandemic blip. In a paper published in 2024, Douglas Gollin of Tufts University in Massachusetts and his co-authors analysed data from surveys of 55,000 household farms in six African countries between 2008 and 2019. They estimated that, for smallholdings, yields and TFP were already falling by 3-4% a year then. They found steeper declines than the FAO did, perhaps because their sample did not include large farms, or because official statistics are sketchy.

Here is more from The Economist.