Crop yields are rising more slowly than they were several decades ago (J. A. Foley et al. Nature 478, 337–342; 2011). This is especially evident in Europe, and has serious implications for its responsibilities in global food production.

In Denmark, France, Finland and Switzerland (see, for example, R. Finger Food Policy 35, 175–182; 2010), the 'yield gap' has increased: the rate of growth in crop yields has declined, even though yield potential has risen over the past few decades owing to technological advances such as crop breeding.

Markets are one contributory factor: lower prices caused by reduced market support have decreased the incentive for investment in equipment, fertilizer, and so on. Also, by restricting the use of pesticides, for example, agricultural policies aimed at reducing environmental damage have hindered growth in crop yields.

Closing these yield gaps will ensure sufficient global food production and help towards food security. More incentives are needed, particularly as low-income countries are also confronted by sizeable yield gaps, for different reasons.