Actually, electric trucks on a farming operation make a lot of sense. They tend to be used for short distances, with a lot of starting and stopping, and tend to have large periods of time they sit idle. They are usually required for work requiring large torque/low speed needs, which electric motors excel at. And large farms tend to have multiple out buildings, all hooked to the grid in some fashion, so adding in charging stations to keep them topped up shouldn't be an issue.
Now, the issue that would be faced, the same as the military with COTS vehicles in the field, is making them robust enough to survive the climatic conditions and off road conditions.