Of course it will. Just like using corn to make ethanol, sending grain overseas will jack up prices at home because supply will be down. Another farmer boondoggle. When they cant sell, they get subsidies. When they can sell prices go thru the roof. Who said farmers lose money?
Of course it will drive up the cost of groceries. Perhaps the tariffs that China pays on their exports will somehow be doled out to the farmers?? But I doubt it.
Maybe now that the farmers will (should have?) an increase in demand from China to raise their prices, Trump could get rid of ethanol to help bring food prices down.