It's probably just you (or the crop is from the downsized photo you gave us a link to, and your seeing some degradation from the resizing).
Also, remember that the focus point was not the grass which was much closer to you. You can't expect the entire scene to be in focus. Depth of Field is related to the distance to subject (focus point), Aperture, and Focal Length of the lens (amount of zoom used).
Give us a link to the full size original, where we can see it without downsizing and look at the EXIF, and we can get a better idea then.