I think you might have trouble composting here, as to create a good one it should be temerate controlled - the centre should reach no more than 60c otherwise it kills all the good bacteria. Since the airtemperature this summer has reached 50c on some days, I think you would struggle to control that.

If you visit the garden centres (there's one just off d-ring and lots just off Salwa Road - near the wholesale markets)they will either have compost, or fertiliser which you can mix with the dirt currently in your garden.

I've tried with herbs here and struggled, however I have 1 basil plant which I just stuck in the sand and it's survived the year!!

Good luck - would be great to know how you get on!