heh, since you asked......
it's really jsut a palette issue that makes the dirt and the grass fight each other rather than sitting on the same plane. the dirt is established as being underneath the grass because it is so warm and the ground is warm with cool figures.
heres an obnoxious MSPaint edit to show how they can be brought together by integrating green light and base to do a few things:
1 - reduce independence of dirt by lowering perceived saturation (complements interspersed = gray overall)
2 - incorporate into ground plane (by adding a cool light)
3 - maintain "heavy" atmosphere (by keeping a warm green base)
just a thought