Yes, I was impressed when Chinese agronomists showed me the lush green fields of rice they were growing in northern Senegal. But that doesn't mean it was a good idea (ecologically) to grow rice in the Sahel. Arid regions are generally full of nutrient-rich dust, which springs to life when watered. Unfortunately, that doesn't make for good long-term agriculture as the water has to be brought in from somewhere else, and usually leaves big salination issues behind in its rapid evaporation in the heat/dryness.