I've written several times about our auto-steer that allows the tractor to follow a previous line and steer itself. We now have systems that allow the combine operator to control a tractor that's pulling a grain cart and unloading into it. So what's going to be topping that?
Fully autonomous machines have been developed that can till and plant with no human intervention at all. It's already possible to have one tractor in the field with a human operator and other tractors doing other operations without any operator on board. These haven't been made available yet, but have been developed. Since I was a child we used to talk of sitting in an office while the tractors did the work and now it's actually looking feasable.
Finally, drones may be a big part of farming in the future. I'm personally looking into small RC helicopters with video and cameras attached to scout my fields from the air. You get a perspective from above that allows you to see things that are just impossible from the ground. It may come to more than that though. If you get larger drones you may be able to spray your own crops from the air or do very sophisticated scouting with infrared to show diseases or bug infestations that can be controlled in a small area before the entire field has to be sprayed. I'm sure these would be hundreds of thousands of dollars, but with tractors running $250,000.00 and higher this could still be a possibility.
What could be next? Only our imagination can limit us. Maybe we will get private access to satellites or something as simple as corn that doesn't have to be dried, saving us thousands of dollars a year in fuel. Our crops themselves may change with us growing different crops for medicine, fuel, or plastics. We have the capabilities of all of these if the economics would pan out. For instance, the packing peanuts that dissolve in water are made from corn. Countertops that rival granite have been made from soybeans, as has fence material and boards that rival wood. Your newspaper probably uses soyink made from soybeans and though it hasn't been completed yet as far as I know, there was a plastic made from corn that would dissolve in the absence of light. Perfect for landfills. All I'm sure of is that what we think can never change will, and we can never count on things staying the same.