National audienceIn an Amazonian frontier, the farmers' migrations, linked with deforestation, are the consequence of the adaptation of the social reproduction rules of a peasant society with its socio-economic environment. This migrations contradicts the principles of the sustainable development, which aims to stabilize these societies. Unless supposing an utopian modification of the logics which governs the socio-economic context of the frontier regions, this stabilization is possible only by the way of a major social transformation of the peasant society. This article studies the stakes of this transformation focusing on the transmission of the land considered as a total social fact: land is indeed the way which allows to the parents the...