Im no desert expert, but I think the type of deserts where you find cactuses like that, dont really have that sort of wavy sand.  The ground is more hard with a loose layer of sand or dirt over it.  Look at these images for example:
http://www.x98ruhf.net/images/arizona_desert1a.jpg
http://spuds.agron.ksu.edu/ArizonaDesert.jpg

personally I thought the image in your first post gets the feel of that type of sand pretty well, though perhaps it could be less noisy.  More importantly though I think the cactus needs to be less noisy.
If you look at a cactus upclose ( http://onlyhdwallpapers.com/wallpaper/cactus_desktop_1536x2048_wallpaper-381716.jpg ) they are pretty smooth.  From a distance its the spines that would make it look  noisy, try to avoid too many spines to avoid noise.  And you could try making the foreground elements (cactus) stand out more against the background perhaps.