Chicago Board of Trade (CBOT) grains futures closed mixed on Tuesday with wheat dropping to its lowest level since early February.

The most active corn contract for May delivery went down 2.25 cents, or 0.62 percent, to 3.6125 dollars per bushel. May wheat delivery skidded 3.75 cents, or 0.87 percent, to 4.265 dollars per bushel. May soybeans rose 2 cents, or 0.2 percent, to 10.015 dollars per bushel.

Wheat futures declined over weather forecasts that it may rain in the wheat-growing southern plains later this week. It's a good news for thirsty grains but pushed down the futures, already pressured by abundant supplies.

Corn futures also went down as rain has started to fall in Brazilian corn-growing areas, which could favor the development of crops there.

Soybeans, thanks to bargain buying, reversed the initial down-turn course and finished higher. Its May contract is now back above the psychological 10-dollar mark.

However, the pressure from ample supplies is still there as a leading Brazilian agriculture consultancy company raised the country's soybean harvest outlook to 111 million metric tons, up from 108 million.