Food systems around the world face a triple challenge: providing food security and nutrition for a growing global population; supporting livelihoods for those working along the food supply chain; and contributing to environmental sustainability. Better policies hold tremendous promise for making progress in these domains.

In the last 20 years, there has been a remarkable emergence of innovations and technological advances that are generating promising changes and opportunities for sustainable agriculture, yet at the same time the agricultural sector worldwide faces numerous daunting challenges. Not only is the agricultural sector expected to produce adequate food, fiber, and feed, and contribute to biofuels to meet the needs of a rising global population, it is expected to do so under increasingly scarce natural resources and climate change. Growing awareness of the unintended impacts associated with some agricultural production practices has led to heightened societal expectations for improved environmental, community, labor, and animal welfare standards in agriculture. Toward Sustainable Agricultural Systems in the 21st Century assesses the scientific evidence for the strengths and weaknesses of different production, marketing, and policy approaches for improving and reducing the costs and unintended consequences of agricultural production. It discusses the principles underlying farming systems and practices that could improve the sustainability. It also explores how those lessons learned could be applied to agriculture in different regional and international settings, with an emphasis on sub-Saharan Africa. By focusing on a systems approach to improving the sustainability of U.S. agriculture, this book can have a profound impact on the development and implementation of sustainable farming systems. Toward Sustainable Agricultural Systems in the 21st Century serves as a valuable resource for policy makers, farmers, experts in food production and agribusiness, and federal regulatory agencies.

This edited collection is an interdisciplinary study of gems in the early modern world. It examines the relations between the art, science, and technology of gems, and it does so against the backdrop of an expanding global trade in gems. The eleven chapters are organised into three parts. The first part sets the scene by describing how gems moved around the early modern world, how they were set in motion, and how they were pulled together in the course of their travels. The second part is about value. It asks why people valued gems, how they determined the value of a given gem, and how the value of a gem was connected to its perceived place of origin. The third part deals with the skills involved in cutting, polishing, and mounting gems, and how these skills were transmitted and articulated by artisans. The common themes of all these chapters are materials, knowledge and global trade. The contributors to this volume focus on the material properties of gems such as their weight and hardness, on the knowledge involved in exchanging them and valuing them, and on the cultural consequences of the expanding trade in gems in Eurasia and the Americas.