Here is another article about the Saudi production of wheat. They are phasing out local production of wheat by 2016 because they were depleting their own fossil water resources.
Check this article of the LA Times . They claim that Africa will be plundered by foreign investors who want to buy land, invest in irrigation and transfer technology. I consider at least risky, or even plain stupid, to invest in a country where exports can be blocked at anytime and the cries for nationalization...