Production agriculture faces an abundance of challenges with climate variability, scarcity and competition for natural resources and volatile energy and fertilizer costs. However, agricultural system models are tools that provide decision support for dryland and irrigated agriculture by combining soil, plant and atmospheric processes to simulate the impacts of precipitation and agronomic, irrigation, nutrient and soil management practices on crop production. Continued integration of field research data and refinement of such models will prove invaluable to optimize production agriculture and environmental management. Experts from different disciplines will discuss aspects of system modeling that are critical to future advancements.