I would suggest that you go out in your
neighborhood street after a rain shower and scoop
up some of the grit , the tiny little pebbles and
small particle sand that collects in low lying
areas of street curbs. I keep mine in a jar.
Find a piece of screen or strainer type "contraption"
that has a very fine screen. Then go to a near by
park and tool over to the playground area where there
is sand around the swings, etc. Scoop up a small jar
full of that — probably a 5 yr. supply, at least — and when you get home, sift it thru the screen so only the very tiny particles of sand sift throught. In scale the sand particles would be quite tiny. So then you have tiny
ittle rocks and very fine sand. Yes, you can buy this stuff from hobby dealers, but it is expensive.
And mother nature provides just what you would want
IMO.
Mix Elmer's (we call it white glue) with water and brush that in the areas where you want your sandy soil to be and then start sprinkling the sand/ pebble over the wet
area. I turn the base upside down and tap it on the
bench a good nock to dislodge the loose particles.
I would keep in mind that in the desert, not every where is just sand and that there is actually growing foliage in the desert, altho rather on the brown side in color. Also, in my view, the desert is NOT flat. There is a rise and
fall to the terrain of the desert. Besides, flat can be
boring
Good luck