This paper suggests a new explanation for changes in economic and population growth with a long run perspective, emphasizing the role of land in the development process. Starting from a pre-industrialization state called the "Malthusian regime&qot;, land and labor are the main production factors. The size of population is limited by the quantity of land available for households and by incomes. Technical progress driven by a "Boserupian effect" may push the economy towards a take-off regime. In this regime, capital accumulation begins and a "learning-by-doing" effect in production takes over from the "Boserupian effect". If this effect is strong enough, the economy can reach an "ultimate growth regime". In the different phases, land plays a crucial role.