Sounds like the farming equivalent of Cash for Clunkers. IIRC, Cash for Clunkers rendered the vehicle inoperable by destroying the engine block, and in this case it seems that they cut the axle.
"I hereby certify that the equipment and engine described above has been received by this facility and will be
permanently destroyed for recycling purposes only in accordance with the Heavy-Duty Off-Road Agricultural Equipment Replacement Program Guidelines"
So, at least in CA, it is not legal to export the tractor.
