Ariel Zirulnick: Per Carstedt, executive chairman of the Swedish company Agro EcoEnergy, has a vision for a shrubby tract of land on the north Tanzanian coast. Under his firms plan, farmers who once depended on subsistence work will earn wages on a sugarcane plantation or from selling sugarcane they grow to a planned processing facility.
The factory will process sugar for export as well as for ethanol. The fields will be crisscrossed with irrigation canals and treated with a mix of organic and synthetic fertiliser....