Brazil and Argentina are expected to lose 11 million metric tons of corn output due to a drought that has caused irreversible damage to South America's crop, according to forecaster Agroconsult.

Estimates in December 2011 had Argentina's harvest at 27 million metric tons of corn; now, Agroconsult puts the number at 20 million metric tons. Brazil's harvest has been cut to 61 million metric tons from 65 million metric tons. South America's soybean output will also be harmed by the drought, according to Agroconsult. Soybean production in Argentina has been cut to 49 million metric tons from 53.5 million metric tons, while Brazil's has been reduced to 73.5 million metric tons from the 75.2 million metric tons estimated in December 2011.

Brazil is the third-largest producer of corn in the world after the U.S. and China. Argentina is the second-largest exporter of corn in the world after the U.S.