Résumé
Manage lands without opposing agricultural practices and conservation of natural resources is a major challenge for world agriculture. The model of the Green Revolution is extremely expensive in natural resources and in terms of biodiversity losses. It is, therefore, not applicable to developing countries where family farming predominates. In addition rural areas are becoming increasingly residential and are also being targeted by other productive sectors land including the extractive activities. Thus this competition for water access and plant resources is a strong menace for the future of family farming and more globally for the world agriculture. This chapter concludes the third part of the book by examining the challenges of the use and management of natural resources by family farming models, both at the level of their system of production and in relation to their competition with other agricultural and non-agricultural forms of resource use focusing especially on the crop biodiversity, access to land and water, and challenges posed by environmental change. The practices adopted in family farming systems are put in perspective in relation to their alternatives for long term sustainability and the role of public policy.