First impression -- My first impression was that it was "unloading" not loading, but I guess that is a result of being in the habit of "reading" left to right.
Compositionally, it is a good action series, but it seems a bit "cramped" on the left side of the image. Tractor #1 is right at the edge of the frame, whereas #3 still has a lot of space. As a result, it looks like the shot was framed too far to the left. Also, the mowers are cutting through the exact (well, visually, anyway) center of the shot. While this can sometimes be effective, in this shot it makes it seem a bit static. Perhaps varying the amount of foreground or "sky" would help throw it off center.
Technically, the colors are pretty good. The red building serves as a nice contrast to the green, and it also catches the eye and gives the viewer somewhere to "start" looking. It could need just a touch of contrast, BUT I'm on my laptop, so I suspect it is about right. Overall the lighting is a bit flat (overcast day, perhaps?) and the focus doesn't seem as sharp as it could be. It doesn't look out of focus, there is just not a lot of detail present in the tractor and driver. It could be because of your distance from him.
Overall, a good impression, but probably not one that would grab a viewer and compel him/her to give this a higher shot.
If I need to further clarify or explain myself, please feel free to contact me.
Wouldn't that be "unloading"? :) Would have liked it better if the two shots on the right were more centered horizontally, but cropped most of the stuff off the bottom so the whole thing wasn't so centered vertically.