The diversity of crop plants is one of our most important biological resources, and the most important source of crop genes are the fields of peasant farmers in regions where crop domestication and evolution have occurred. Today, however, crop genes are threatened by social and technological change such as human population growth, the use of new agricultural technologies, the development of new varieties, and the commercialization of agriculture. Gene banks have been successful in capturing much of the genetic diversity of crop species, but it is also essential that the environmental systems where the crop genes evolve also be conserved. This work provides an interdisciplinary foundation for an important new conservation program: maintaining biological resources of crop plants within the systems where they have evolved. The book offers a global vision of the on-farm conservation movement and provides a comprehensive review of the issues and challenges of on-farm conservation of genetic resources. The book's chapters are written by a collection of outstanding scholars and academics from a variety of disciplines; they include biologists, agronomists, anthropologists, economists, lawyers, and agricultural development specialists. It should appeal to a varied international audience, particularly to professionals in the fields of conservation and agricultural development and those who are involved in planning or implementing conservation programs. For course work, the book is appropriate for graduate programs in agricultural development and conservation.