I am dealing with farmers' reported data on corn production in Nebraska. I want to use elevation data (10 or 2 m resolution) to create some kind of index that can help me to find either land roughness or something else. For example, if in a small area there are 10 farmers and 2 of them are performing better than others. It would be hard to find climatic differences or differences in soil properties. One possibility is that they might have different agricultural management practices, I don't have that data but other possibilities is that soil/land roughness or position of their farm relative to neighboring farms. I don't have much clue into that so posting to request response of you.