Beautiful scene, but I think I would have cropped out a bit more of the left, to take the tree more out of center and to reduce some of the white that pulls you away from the tree. I like the darkness, and I love the angle of the fence!
I like the sky and the grass - god post processing. For me, I would have liked to see the horizon either higher or loweer instead of in the "dead" center.
I know you probably intended this shot to be "dark", however it's just a bit too bland for my liking. I also think the tree and fence leading the eye into the frame could be placed less center.