I was unaware that sand (pulverized, eroded rock) goes to "soil". "Dust" (desiccated soil) may go to soil. But my understanding is, the mineral properties of sand and of soil differ, so therefore the arability of the media.

The Sahara desert, unlike the Gobi for example and purportedly the optimal site of Desertec equipment, is 80:20, sand:soil, unevenly distributed. The  maximum depths of its dunes and packed strata are, basically, unknown.

I found a youtube doc about Libyan (Gadaffi's) investment in reclamation that offers a succinct explanation of the financial and technical hurdles to agricultural success --without even the added expenses of solar and wind siting and maintenance.

Astro turf appears the least cost option.

Diversity is the key to economic and political evolution.