Looking darn good for a first really serious attempt. Mine looked nowhere like that
I agree with the others about the sharpness of the image. Oshyan's suggestion is a good one.
I'd further suggest to test the different pixelfilters with croprenders, but I assume you are already familiar with that approach.
The lighting is very good!
I do not agree with PG to add clouds, because that would disturb the balance a lot in my opinion.
So hopefully you want make the mistake to fill every bit of the picture with lots of stuff.
Also, when adding foliage etc. don't over-do it.
It is nicely balanced now and the slightly overcasted sky gives this image a really staggering hot desert feel.
Martin