In French Guiana, the general environmental context and the growing need for energy and food products, linked to population growth, are responsible for increasing pressure on natural resources through land use changes. Low impact practices are emerging in the aim of reconciling production and environmental objectives. In French Guiana slash and burn practices are still used to increase agricultural area, and lead to a large loss of carbon. A field survey was carried out in order to understand the place of soil in farmers' choices, and to obtain a description of production systems and practices, focusing on identifying those with low impact on carbon dynamics. This step was realized through specific soil carbon stock measurements. Our results show that the "soil object" is mastered by farmers in terms of physical properties, and organic matter is a recognized indicator which is used to inform spatial management of farming systems. Farmers mobilizing low-impact practices have efficient production systems for their economic and environmental benefits.