Best way to segment farmers when doing market research for agri-inputs?

You're right that smallholders and commercial farms are almost completely different buyer personas — I'd start by segmenting on farm size (acreage or hectares), then layer in decision-maker type (owner-operator vs. hired farm manager) since that changes the whole purchase dynamic. For agri-inputs specifically, crop type and input spend per season are usually the most predictive variables for behavior. We've had good results running a quick cluster analysis on just those 3-4 variables before going deeper into attitudinal stuff.