Nice shot, and a good magazine cover, with a vertical format and space at the top that could carry type without spoiling the picture. I assume these machines are used for farming; they look like some kind of high-tech irrigation system, but that's just a guess.
Ah, Nebraska artillery. Nice exposure, dynamic composition and no question where the type goes. This shot would benefit from a nice sunset or puffy white clouds, but those can be tough props to find. Looks like you found a use for a Parallel Lines outtake, too ;-)
I can totally see a photo like this on the cover of Farm Journal. You've not only captured the subject extremely well, but the essence of the magazine. And you've left plenty of room for title and text. Very, very nice.