There are no signs to identify a barren field in northeastern Brazil that was meant to be the center of one of China’s most ambitious agricultural forays into South America. In 2011, Chongqing Grain Group Corp announced plans to build a soya crushing plant, railways and a giant inland storage and transportation hub to export goods back to China. The total price tag: $2 Billion US. Yet today, the company has only managed to bulldoze a 100-hectare area on which the crushing plant might one day stand. Even…