Here is another flying machine that can make life easier for farmers. The Field Hawk Ag+ Drone features a M4 quad camera array and PixHawk 2.1 w/ Intel Edison. It does NDVI and RGB photos. The drone has a lightweight and is completely autonomous.
The Field Hawk Ag+ is compatible with Mission Planner and can fly for up to 25 minutes on a single charge. It covers 160 acres on 1 battery.