Soils, agriculture and food security: the interplay between ecosystem functioning and human well-being

•Soils provide ecosystem services that go way beyond agricultural production.•Soil degradation can be controlled and a series of adapted technologies are available.•The great challenge in agriculture is to achieve both productivity and sustainability.•Smallholder farming has the highest need, but also the best agricultural potential.•Food security for all must be negotiated within societies, including all stakeholders.

Healthy soils are critical to agriculture, and both are essential to enabling food security. Soil-related challenges include using soils and other natural resources sustainably, combating land and soil degradation, avoiding further reduction of soil-related ecosystem services, and ensuring that all agricultural land is managed sustainably. Agricultural challenges include improving the quantity and quality of agricultural outputs to satisfy rising human needs, also in a 2 degrees world; maintaining diversity in agricultural systems while supporting those farms with the highest potential for closing existing yield gaps; and providing a livelihood for about 2.6 billion mostly poor land users. The greatest needs and potentials lie in small-scale farming, although there as elsewhere, trade-offs must be negotiated within the nexus of water, energy, land and food, including the role of soil therein.