Do you have any noise removal software like NeatImage or Noise Ninja? If not, I urge you to check out the trial versions. I was fully amazed by NeatImage when I tried it and happily shelled out the $40 or so for the full version. It can work wonders (or at least usually help!).
Why so much pixelation and distortion? Without that this would proably be a really good photo! I can see how the HDR would have worked especially on the grass.