Book excerpt: Reprinted from Plant and Soil, v.174, nos.1-2 (1995), this volume is devoted to discussions on the role of biological nitrogen fixation (BNF) in agricultural sustainability. Papers presented on BNF in crop forage and tree legumes are augmented with discussion of integrated farming systems involving BNF, soil and N management, and recycling of legume residues. BNF by non-legumes is discussed and attempts to transform cereals into nodulating plants are critically reviewed. Also described are advances in the development of new methodologies to understand symbiotic interactions and to assess N-2 fixation in the field; means of enhancing BNF through plant and soil management; breeding and selection; problems encountered in exploiting BNF under farmers' field conditions; and promising approaches to improve BNF exploitation. Lacks a subject index. Annotation copyright by Book News, Inc., Portland, OR