The Algerian steppe suffered for several decades a serious problem of desertification, under the combined effect of anthropogenic and natural factors. This desertification means the installation of a "semi-desert" ecosystem in place of the steppic ecosystem which used to support an ancestral socio-economic system based on pastoral livestock. The scarcity of forage resources, the decline of farming activity and the degradation of living conditions of steppe inhabitants are among problems posed by desertification on nearly 80% of agricultural land in the country. The fight against this phenomenon constitutes a strategic challenge for Algeria for which significant public funds have been committed. The mixed results of these efforts prove the ineffectiveness of the adopted approaches and methods. Exploring new approaches to analyze the problem of desertification and consider new ways of thinking and implementing the fight against this phenomenon and more generally for sustainable development of the steppe, is required. This paper shows the first results of a project on participatory action research which is testing a bottom up and integrated approach to fight against desertification based on the reorientation of the agro pastoral systems towards a logic that attempts to reconcile valorisation and sustainable preservation of rangelands natural resources. Five integrated models of agro pastoral production systems have been designed with the active participation of rural development actors, including agro pastoralists. These models are currently being tested with a group of agro-pastoralists experimenters.