It's all machined, no manual labor. Instead of sparying you would roll the pasture with already existing farming machinery. They use the same no till sower as other no-till methods.
There's still a fair bit of labor, but most of that now takes the form of repair and maintenance work on machines.
Modern farming is hyper efficient and basically 90% automated.
That said, the remaining 10% market is probably a 100B-1T market opportunity (seriously). Not many startups either.