Chicago agricultural commodities edged down Tuesday with corn, soybeans and wheat dropping. The most active corn contract for July delivery fell 8.25 U.S. cents, or 1.73 percent, to close at 4.6975 U.S. dollars per bushel. The most active soybean contract for July delivery fell 26.75 cents, or 1.77 percent, to close at 14.8875 dollars per bushel. The most active wheat contract for July delivery fell 11.5 cents, or 1.76 percent, to close at 6.41 dollars per bushel. Corn fell as very positive weather was forecasted. Additionally, China announced that it will auction off more than 3 million metric tons of corn this week, which is expected to be in strong cash demand. Soybeans fell as the El Nino weather phenomenon continues to rapidly form and is near its arrival in the equatorial Pacific. In another two weeks, analysts expect that the United States will officially declare the arrival of El Nino and its likely persistence into the end of the 2014. El Nino that forms during the summer tends to correlate with average or above average U.S. corn and soybean yields. Wheat fell as favorable central U.S. and world weather and slowing U.S. demand have pressured sharp losses. The central U.S. weather forecast remains nearly ideal for late May and early June with near to above normal rainfall and near to above normal temperatures. Planting efforts for corn and soybeans across the vast majority of the U.S. Plains and Midwest are pushing strongly ahead and most will be completed with seeding by the opening days of June.