In the 1980s and 1990s, green manure/cover crop (GMCC) systems became a popular agricultural technology in research and development efforts for smallholder tropical and subtropical farmers. However, few syntheses of these experiences have been conducted. This volume of case studies contributes to bridging this gap by reviewing field-level experiences with these systems. Twelve case studies are included. Eleven of them describe experiences from Latin America (4 cases), Africa (6 cases) and Asia (1 case) and the twelfth case reports on the development of a GMCC systems database. Two concluding chapters, `Learning from the Case Studies' and `Future Perspectives', build upon the cases. The systems described are diverse. Some systems have been spontaneously adopted by farmers, while others have been introduced to the farmers through diffusion efforts. Some of the cases reviewed describe small, localized efforts while others report on large-scale, well-known ones, such as the combination of GMCCs and conservation tillage in Santa Catarina, Brazil, the maize-Mucuna system in northern Honduras, and the improved fallow systems in Eastern Zambia. Most experiences include both development and research aspects and to the extent possible the cases integrate these two. Discussion of the strengths and shortcomings of the systems and efforts is frank, and the goal is to learn from these experiences to benefit future efforts. It is expected that both researchers and development practitioners and students of tropical farming systems and soil management will find this volume of case studies useful.

Lessons learned in Latin America is about the use and dissemination of cover crops in different agreoecosystems need to be made more widely available not only to Spanish speaking, but also Anglophone regions. This publication aims to inform a wide range of actors involved in rural development projects, as well as those in applied research, about the potential of cover crops as components of low external input agricultural (LEIA) systems. Cover crops are, or have the potential to be, an important component in complex, diverse, risk-prone and resource-poor farming situations. The publication includes selected case studies from four different countries in Latin America. These address key issues regarding crop cover integration in LEIA systems. A wide range of agroecosystems are covered by the case studies, so that the information can be adapted for use in other regions. The key issues covered by the case studies are the following: Cover crops in annual cropping systems (Honduras); Cover crops in perennial crops (Bolivia); Role of cover crops in animal husbandry (Mexico); cover crop systems - soil improvement and conservation (Honduras); Alternatives to slash-and-burn (Mexico); Diffusion aspects of cover crop based systems; Applied research activities for agricultural systems improvement (Bolivia); and Action research with campesino farmers in South-east Mexico. However, the different aspects of cover crops cannot be treated separately from each other. The cross-cutting nature of the different aspects of cover crops becomes obvious from the case studies themselves, and the treatment highlights potential applications in other contexts.