This book is centred on the 'production processes' of crops and pastures - photosynthesis and use of water and nutrients in fields. The book is unique in its combination of great breadth and depth in its treatment of production processes and systems problems. The approach is explanatory and integrative, with a firm basis in environmental physics, soils, physiology, and morphology, in contrast to descriptive or reductionist approaches. Systems concepts are introduced early and expanded as the book proceeds, giving emphasis to quantitative approaches, to management strategies and tactics employed by farmers, and to environmental issues. The systems approach is brought together in the final chapters where production and nutrient cycling are analyzed, for example farms and problems in an uncertain future are considered. The book is based on courses taught by the authors in Australia and the United States and is designed for use as a text for an introductory course in crop ecology (advanced undergraduates and beginning post-graduate level). It is more than a text, however. Given the wide range of subjects, the authors have integrated reference and background material to create a 'stand-alone' reference work useful to a wide audience of agriculturalists.