The recent surge in agricultural prices was a wake-up call: never before has the world faced a food crisis on such a scale. But the difficulties have only just begun. Today, 925 million people on the planet suffer from hunger, and their numbers are growing ever faster. In addition to rising commodity prices, the scarcity of water and arable land, and the ravages caused by climate disruption, two recent phenomena have come to the fore: at the very moment when China's demand for cereals accelerated sharply, biofuels began to redraw the map of world agriculture. As for agricultural productivism, which has exhausted the soil and polluted the environment, it has reached its limits...