I think there are some funny things about this image, that don't make it very realistic. If realism is your intention. To mention: the blurry distance, the fat low clouds, and the 'huge' plants.
To me this landscape gives a sense of great scale, and as such the landscape (soils) is great, but try it with softer, more transparent (perhaps more distant) clouds, no blur in the distance and reduce the plants 1/10 and clump them as choronr suggested. I would more likely put a farmstead, ruin, dead tree or another grand object somewhere in front, to reference the scale. And not make it too big.
---Dune