Nearly anyone who has spent at least a little time planting, nursing and harvesting a crop of corn has witnessed variability of its performance within a field. The existence and magnitude of yield variability has become much more obvious with the advent of precision farming technologies. Naturally, these observations then lead to thoughts such as:

• What factors are creating the varied growth and yield of my corn?
• Are there things I can do differently to increase production in the lower yielding areas?
• Are there areas I can reduce my inputs without reducing yield and increase net profit?