Test at the juinction of the lines that come from the injector pump go into the injectors, Crack a line slightly and look for fuel, while cranking, I am betting you will not find any. While you are at it you might want to put your battery on a charger, depending how much cranking you have done. Don't crank for more than 10 seconds at a time, then rest for a bit, no sense overheating your starter. I am hoping someone else that is familiar with this model of Kubota can tell us more about the fuel solenoid in more detail if it comes to that. First question, you never answered, is when you turn the key on just before you start to crank do you hear the big "click" of the fuel solenoid being energized. You should also be able to feel it on the injector pump with you hand while someone else turns the key.
James K0UA