The Plain of Jars is an acid, infertile savannah grassland covering an area of about 60,000 ha in the western region of Xieng Khouang Province, northeastern Lao PDR. In this ecology, farming systems are mainly based on lowland rice cultivation and extensive livestock production. An increase in rice production and intensification of the livestock industry are two key components in the Lao government's poverty alleviation strategy for this area. The main agronomic constraints for developing crops and forage systems are related to serious unfavourable soil chemical characteristics. Low pH, along with nutrients deficiencies (in nitrogen, phosphorus, potassium, calcium and magnesium) and high levels of aluminium saturation probably have a negative effect on the growth of upland crops, as well as many pasture species. Moreover, severe phosphorus deficiency generates animal health problems. Since 2004, the Lao National Agro- Ecology Programme (PRONAE) has been working on innovative farming systems based on direct seeding mulch-based cropping system (DMC) principles, as a technical approach, and on a progressive in situ validation process with smallholders as a Research & Development (R&D) approach. The advantages of the methodology are presented through the case of a DMC system developed in 2005 by the project to intensify rice-beef production in the Plain of Jars. The farming system initially proposed was a 5-year rotational sequence where improved pasture land was implemented in the first year, fattening activities conducted in the following three years and pasture regenerated in the fifth year using rice as a cash crop to finance pastureland re- implantation. Costs and benefits of the system were simulated according to the data collected in the creation sites. At the end of the 5 years, an average net income of 160 $US/ year/ha and an average labour productivity of 2.5 US$ per ha and working day were expected. The system was then proposed to 89 families forming