''Specific research needs relating to crop improvement for drought resistance must be considered within the broader context of a total agricultural research and extension strategy. At the simplest, the goals of such a strategy are to develop appropriate technologies for increasing the efficiency of food and fiber production while maintaining the long-term stability of the land resource. Whatever the goals, implementation of new technologies ultimately rests with millions of individual farmers. Each farmer and his farm is unique. How do we prescribe a technology that is relevant to the land, labor, capital, and management resources of each individual? If, given a specified minimum set of soil-crop-weather and management data, it were possible to predict the performance of a particular crop system at a particular location, then it would be possible to predict an appropriate technology. This is an attainable objective, but it requires major shifts in the prevailing logic and methods of agricultural research (Nix 1968, 1976, 1979). Basically it requires a shift in emphasis away from the currently dominant reductionist or analytical approaches to holistic or synthesizing approaches. These two approaches are complementary rather than competitive. Adopting a systems approach emphasizes the need for interdisciplinary teamwork. Knowledge and insight from the range of biological, physical, social, and economic disciplines become necessary. It formalizes what is known about crop production systems — their more important components, processes, and feedback mechanisms — and helps to identify significant, subtle constraints. Most importantly, the possible consequences (ecological, agronomic, economic) of introducing a new technology can be evaluated by using modeling and simulation techniques and field experiments designed to test model predictions...''