Spencer, IA: (Oct 05, 2012) - Brazil’s vast cerrado is finally running out of acreage for agricultural expansion. The cerrado, a vast expanse of tropical savannah and shrubland three times the size of Texas, has been converted in recent decades to one of the world’s most productive breadbaskets.  But Brazil’s corn grower association says there are only about seven million hectares of potential farmland that has not yet been used.