Grain futures closed mixed Monday on the Chicago Board of Trade. Corn was off 4 1/2 to off 7 1/4, soybeans were up 2 1/4 to up 10, wheat was off 7 to off 12 1/4 and oats were off 3/4 to off 3. Light trading in corn and wheat shifted prices lower with traders hedging bets to position themselves correctly ahead of Tuesday\'s U.S. Department of Agriculture\'s supply and demand report. Soybean prices rose, although gains were tempered by improved weather conditions in southern Brazil. The prices: Corn: Dec 7.26 3/4 off 6, Mar 7.30 off 7 1/4, May 7.32 1/4 off 7, Jly 7.31 off 4 1/2. Soybeans: Jan 14.74 3/4 up 2 1/2, Mar 14.75 1/2 up 3 1/2, May 14.62 3/4 up 9 1/2, Jly 14.51 1/2 up 10. Wheat: Dec 8.32 3/4 off 11 1/2, Mar 8.48 3/4 off 12 1/4, May 8.60 1/4 off 10, 8.66 3/4 off 7. Oats: Dec. 3.74 off 3/4, Mar 3.89 1/4 off 2 1/4, May 3.92 1/4 off 2 1/2, Jly 3.90 1/2 off 3.