What is called ‘conventional’ agriculture rests on a chain of practices that are coherent, yet fragile : standardized varieties, soluble fertilizers, pesticides, ultra-mechanization. This ‘model’ is particularly ill-suited to non temperate climates. On the contrary, organic agriculture favours plant varieties that are adapted to the environment while giving importance to the farmers and to the ecosystem. A serious evaluation must not compare the production rates of conventional and ‘chemical free’ wheat, but the gross potentiality of two parcels with two different systems of production. In this perspective, organic production is often superior to conventional production. Concrete questions emerge as to the reconciliation of eating habits and contemporary agricultural systems.