Chicago Board of Trade (CBOT) agricultural commodities closed mixed Thursday, with wheat, corn futures bouncing back as investors added buying after two central bank meetings fueled a downdraft in the dollar, while soybeans closing slightly lower.

Corn led the gains as the most active corn contract for July delivery rose 6.5 cents, or 1.69 percent, to close at 3.9125 dollars per bushel. July wheat delivery added 2 cents, or 0.41 percent, to close at 4.855 U.S. dollars per bushel. Soybean for July delivery lost 1 cent, or 0.1 percent, to close at 10.275 US dollars per bushel.

The U.S. dollar showed weakness for a fifth straight session Thursday, sending Chicago grains higher, after Japan's Central Bank failed to offer any new monetary stimulus as expected, and the U.S. Federal Reserve continued to put off raising interest rate.

Generally, the Fed increasing interest rates would send the U.S. dollar higher. Analysts noted a stronger U.S. dollar can be a negative for agricultural commodities, priced in U.S dollars, as it makes them more expensive for non-dollar users, while a weaker dollar can support dollar-denominated commodities.

The U.S. Department of Agriculture said Thursday in its weekly export sales report that for the week ending April 21, the United States witnessed exports of soybean going down by 18 percent from the previous week and by 20 percent from the prior four-week average.

Corn export sales were down 15 percent from the previous week and 4 percent from the prior four-week average, while wheat exports were down 6 percent from the previous week, but up 16 percent from the prior four-week average, according to the report.

Analysts said the weekly U.S. export sales were better than expected in corn, old crop wheat.

July soybean on Thursday ended slightly lower on talks the soybean harvest in Argentina continued to gain speed with yields reported as better than expected in all but the extremely flooded area.