The present inventors have recognized that a pressure gradient or differential in a product distribution line for conveying granular particulate material, such as seed or fertilizer, in an air flow to an agricultural field consistently decreases as air speed (velocity) in the product distribution line decreases until a critical air speed is reached. Below the critical air speed, the particulate material may become susceptible to falling out of the air flow to potentially cause a blockage in the system. Accordingly, a control system can implement a process for efficiently determining an optimum operating velocity for an air flow that is above the critical air speed yet below a maximum air speed associated with inefficient operation. In one aspect, the optimum operating velocity can be stored as a value corresponding, for example, to the type of particulate material and/or rate at which the particulate material is metered for subsequent use.
