Non-Peer ReviewedThe advent of the world energy crisis in 1973 aroused interest in the potential of nitrogen-fixation for increasing agricultural production. Since then, sustainable agriculture has become the focus of attention. Sustainable agriculture involves design and management of procedures which work with natural processes to conserve resources, and minimize waste and environmental damage, while maintaining farm profitability. As agriculture moves towards greater sustainability, the potential role of nitrogen-fixation processes increases. As a result, the agronomic significance of nitrogen-fixation has generated renewed scientific excitement in this area of microbial-plant interaction. A number of significant advances in applied nitrogen-fixation technology have been made: improved rhizobial delivery systems, increased nitrogen-fixation capacities, greater yield and improved quality of legumes, and better definition of the role of nitrogen-fixation in N cycling. Shifts in agricultural sustainability that involve these improved nitrogen-fixation technologies require continued research efforts to assess the levels of resource conservation, impacts on the environment and the economic consequences
