But they're going to need pretty advanced many-flight mission planning capabilities to really work. And they're going to need to be incredibly resilient/repairable.
Why? Well, look at the stats, you do the math:
> 50 kg spreading. Spreading 108 kg/min.
Yeah maybe it's not spreading/spraying at full tilt all the time. But it probably does need to be able to make dozens or hundreds of trips & refills a day to be of service on a real farm.