Likely Republican presidential candidates at the first-ever Iowa Ag Summit in Des Moines strongly supported efforts to expand agricultural trade and backed gen­­etically modified crops and rebuilding inland waterway infrastructure, while sharply criticizing a plan by the Environmental Protection Agency (EPA) to ex­­pand federal jurisdiction over water.

"Free trade will be one of the great wins for U.S. agriculture and will really do more for the rural economy than anything else," said former Florida Gov. Jeb Bush. "It’s a fantastic opportunity for us to expand markets in places like Japan and Korea and all over Southeast Asia."

Biofuels differences

However, the candidates offered differing views on the Renewable Fuels Standard (RFS), which is strongly supported by Iowa leaders, including Gov. Terry Branstad and Iowa Sen. Chuck Grassley, as a way...