@Ali
about 'same colored adiacent fields' my thougt is I would avoid to fragment too much the fields, I'm afraid of patch-work looking.
In the pict below u can clearly see a lot of adiacent fields of the same color, they are differentiated by edge row, trees and so on. Here's why I made in this way. i'm with u it doesn't look good without edgerow and trees layer.
pict1.jpg
cheers