Working with the 50mm

I shot this picture @ Alba. Wich is a place near my town were there used to be a factory. They gave it back to nature. I was trying to isolate the grass from the rest creating a small dof. I am not disappointed with this result, though it would have been nice if the grass was more sharp. It was a very windy day so even at this high shutterspeed i can see movement.
Shot info: iso 200/f4/1:1250/50mm, cropped and added a bit of contrast in Capture NX2.