Technical Abstract: Summer fallow has played a significant role in dryland cropping systems in the Central Great Plains for many years. Although it helps to stabilize crop yields, summer fallow jeopardizes the long-term sustainability of dryland systems by degrading the soil resource and limiting profitability. We argue that a dynamic system involving flexible fallow, whereby a grower's decision to transition from a summer crop to winter wheat with a short-duration spring crop or summer fallow is based on several dynamic factors including soil water and economics, would be preferable to a static system incapable of responding to the highly variable climatic and economic scenarios indicative of the region.