Sao Paulo, Aug 24 (Reuters) - Brazil's essential role as a provider of food for the world's expanding population is at risk if the government makes good on threats to curtail foreign investment in farmland. The late Nobel laureate and U.S. agronomist Norman Borlaug, who is widely recognized as the father of the Green Revolution, predicted Brazil would become the world's breadbasket in the 21st Century, as the United States was in the 20th. Read more of this analysis by Reese Ewing.