In the first edition of this book, published in 1992, we presented two case studies of important farming systems, wheat–sheep farming in southern Australia and maize–beef production in central USA, discussing how they operated based on current knowledge, technology, and economic conditions. The purpose was to integrate the knowledge and principles presented in earlier chapters and show how success in farming depends upon this integration. Economic survival required a sustainable system, which could be analyzed in terms of balances of water, nutrients, and capital. In addition, farmers had to be nimble in adapting to variable climatic and economic environments. We also hoped that those analyses would serve to encourage readers to make detailed analyses of other farming systems. Those examples remain available to readers on the internet and can continue to meet those goals. However, and unsurprisingly, these analyses are substantially out of date with regard to current cropping systems in those regions. Knowledge and technology have advanced rapidly, global population and demand for agricultural products have increased substantially, and economic conditions have changed dramatically.

In this edition we wish to emphasize that dynamic nature of agricultural and farming systems and stress how developments in technology have and will continue to provide farmers with the capacity to remain economically viable over the short term, and sustainable over the longer term. For this we present two new chapters. Chapter 16 examines the development of wheat production systems in southern Australia since inception of the industry in 1850.