Yep, use commercially available 'ground cover' materials, such as static grass and tufts, over a base covered with 'sand' mixed from scatter materials, from any model railway outlet, as well as Model Hobbies. These are basically dyed sawdust, in many colours representing grass, earth, sand, stone, etc etc. A couple of types, mixed together, should give the desired effect.
You can also use real sand, from B&Q or builders merchants, in the fine variety. For my 1/32nd scale desert Beaufighter base, I used real sand from the Sahara desert - brushed from the roof of my car, after one of those freak rain and wind storms carried the sand from North Africa to northern England !