Corn prices fell more than 3% to around $5 a bushel, their lowest level in five weeks, after the USDA (U.S. agriculture agency) reported inventories above market expectations. Corn stocks on September 1 totaled 2.095 billion bushels, versus trade estimates of 1.918 billion, indicating a larger-than-anticipated supply cushion. Traders were also monitoring the U.S. harvest, with forecasts for continued rain raising concerns that wet conditions could slow fieldwork. Farmers had harvested 18% of the corn crop as of Monday, matching the five-year average, the USDA said. Broader weakness in grain markets also weighed on corn after China left soybeans out of proposed tariff reductions on U.S. agricultural goods. Corn was included in the proposed tariff cuts, but the agreement contained no new commitments to buy U.S. corn.