Being able to operate heavy machinery with precision is a one. When talking machines that cost half a million dollars, often with low operator visibility, a simple mishap can cost a fortune to repair.
*When talking machines that cost half a million dollars*
Base unit, no accessories. A brand new John Deere combine can list for around $450-500K--not including heads, precision ag systems, etc. Tack on a couple hundred thousand more for those.
All for a piece of equipment used 3-4 weeks out of the year.
New tractors are running around $150-$250K. Even 30+ year old tractors with good hours on them run about $27-30K at auction.
Some ag dealership labor rate for repair will make you wish you were paying car dealership rates.
Having a commercial applicator's license (herbicide/pesticide).
Trained implement mechanic.
Certified manure applicator (for commercial manure applicators and certain classes of confinement operators, and different from the commercial applicator license aforementioned).