Grilled lamb

[giannisna]

It is a tradition in Greece to eat grilled lamb every easter. I took this picture of the lamb while being grilled and i processed it in PS (cropped to 16:9, sharpened with high pass filter, made the sky a bit darker by lowering the exposure because it was too white, lightened the trees and the lamb with brush, some curves adjustments to make the grass look more green and added contrast and saturation). What i noticed is that it looks a bit fake where the sky meets the trees and the lamb. Especially the lamb looks as its not part of the original photo but it was added later (there is a line that separates it from the background). I 'd like to ask how can i fix this problem and also what do you think about the cropping and the colors (is the picture to yellow?). I will also post a link to the original photo so you can compare.
Thank you very much in advance!

From Drop Box

Model NIKON D3100
Date/time original 4/24/2011 1:40:31 PM
Shutter speed value 1/200 s
Aperture value f/7.1
ISO speed ratings ISO 100
Exposure bias value 0.00 eV
Metering mode Pattern
Flash Flash did not fire
Focal length 18 mm
White balance Auto white balance

Original photo: DSC_0980.jpg picture by giannisna - Photobucket