It would have been very easy to expand on all the sections of the first edition but I decided to try to retain the relatively short, introductory nature of the book. Some new material has been added, particularly where it has been possible to update data, and there has been some change of emphasis in places, in order to reflect changing world conditions. The book retains its original purpose, however, of introducing systems thinking as applied to agriculture. I am grateful to Angela Hoxey for help in preparing this edition, especially in relation to the preparation of tables and figures. C. R. W. SPEDDING v Preface to the First Edition The agricultural systems of the world represent a very large subject. Their study involves a great deal of fairly detailed knowledge, as well as a grasp of the structures and functions of the systems themselves. This book has been written as an introduction to such a study and it concentrates on an overall view, rather than on the detail, partly because of the need to relate the latter to some larger picture in order to appreciate the relevance and significance of the detail. This problem-of seeing the relevance of component studies and the significance of physical, biological and economic detail, and indeed principles-is encountered by many agricultural students right at the beginning of their university careers.

Agricultural Systems, Second Edition, is a comprehensive text for developing sustainable farming systems. It presents a synthetic overview of the emerging area of agroecology applications to transforming farming systems and supporting rural innovation, with particular emphasis on how research can be harnessed for sustainable agriculture. The inclusion of research theory and examples using the principles of cropping system design allows students to gain a unique understanding of the technical, biological, ecological, economic and sociological aspects of farming systems science for rural livelihoods. This book explores topics such as: re-inventing farming systems; principles and practice of agroecology; agricultural change and low-input technology; ecologically-based nutrient management; participatory breeding for developing improved and relevant crops; participatory livestock research for development; gender and agrarian inequality at the local scale; the nature of agricultural innovation; and outreach to support rural innovation. The extensive coverage of subjects is complemented with integrated references and a companion website, making this book essential reading for courses in international agricultural systems and management, sustainable agricultural management, and cropping systems. This book will be a valuable resource for students of agricultural science, environmental engineering, and rural planning; researchers and scientists in agricultural development agencies; and practitioners of agricultural development in government extension programs, development agencies, and NGOs. - Provides students with an enhanced understanding of how research can be harnessed for sustainable agriculture - Incorporates social, biological, chemical, and geographical aspects important to agroecology - Addresses social and development issues related to farming systems

Why model? Agricultural system models enhance and extend field research...to synthesize and examine experiment data and advance our knowledge faster, to extend current research in time to predict best management systems, and to prepare for climate-change effects on agriculture. The relevance of such models depends on their implementation. Methods of Introducing System Models into Agricultural Research is the ultimate handbook for field scientists and other model users in the proper methods of model use. Readers will learn parameter estimation, calibration, validation, and extension of experimental results to other weather conditions, soils, and climates. The proper methods are the key to realizing the great potential benefits of modeling an agricultural system. Experts cover the major models, with the synthesis of knowledge that is the hallmark of the Advances in Agricultural Systems Modeling series.

A unique look at how the adoption of sustainable farming methods is being pursued throughout the world. This comprehensive book provides clear insight into research and education needs and the many points of view that come to bear on the issue of sustainability. Essential for agricultural leaders in research, education, conservation, policy making, and anyone else interested in creating an economically and environmentally sustainable agriculture worldwide.

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.

Continued population growth, rapidly changing consumption patterns and the impacts of climate change and environmental degradation are driving limited resources of food, energy, water and materials towards critical thresholds worldwide. These pressures are likely to be substantial across Africa, where countries will have to find innovative ways to boost crop and livestock production to avoid becoming more reliant on imports and food aid. Sustainable agricultural intensification - producing more output from the same area of land while reducing the negative environmental impacts - represents a solution for millions of African farmers. This volume presents the lessons learned from 40 sustainable agricultural intensification programmes in 20 countries across Africa, commissioned as part of the UK Government's Foresight project. Through detailed case studies, the authors of each chapter examine how to develop productive and sustainable agricultural systems and how to scale up these systems to reach many more millions of people in the future. Themes covered include crop improvements, agroforestry and soil conservation, conservation agriculture, integrated pest management, horticulture, livestock and fodder crops, aquaculture, and novel policies and partnerships.