Thanks!
One little crop against the sun:

@ Dune:
It is indeed clouds, if you doubt it, then maybe the method is useful.
Although the idea to make this image came from some problems with my trees leaves, I never intended to use clouds as real substitute.
I wanted it to look like clouds, and hence used at least medium quality settings.
I used 7 cloud layers (far mountains,hills, far bushes,two layers of "grass", the yellow "flowers" and the tree) and distance shaders, the planets surface is disabled.
I am sure there is some way to make the clouds follow the terrain, maybe dandelOs metaclouds could help. His grass-shader definitly rendered faster than my clouds.
I would rather have it look more like real clouds in the shape of a landscape than looking more "realistic"
Best Regards,
Jan