Introduction to Yield Variability.

My role in this symposium is to moderate the presentations and subsequent discussions.  The symposium was organized in light of two major challenges facing precision agriculture today.  The first challenge is that adoption of precision agriculture is slower than anticipated in spite of the proliferation of technology on the farm.  A reason given by top farmers is that they do not understand the yield variability they have observed within their fields over more than a decade of yield monitoring and are uncertain how to manage it for improved crop yield and quality even though they apply inputs site-specifically.  The second challenge for precision agriculture emerges from a credible notion that precision agriculture will be needed to achieve solutions to the global challenges of feeding the growing world population in a sustainable way in the face of depleting land, soil, water, and input resources and in response to climate change.   Life science companies suggest much of that yield increase will come from improved crop varieties through breeding and genetics but that precision agriculture will be required to maximize seed potential in diverse environments found within fields.   Precision agriculture must provide the knowledge and capability of varying crop variety and plant population through variable seeding rate and row spacing and match fertilizer, water, and crop protection inputs to that environment in verifiable sustainable and traceable ways.  The speakers at this symposium will provide important insights to the science and management principles needed to understand and manage yield variability.