Wheat futures jumped more than 14% this month before trimming gains as rain aided crops in the U.S. Plains region. Prices were driven higher by both weather concerns and the possibility of a supply disruption due to the tension between Ukraine and Russia.

Corn futures ended the month on a bullish note as a Department of Agriculture survey showed U.S. farmers plan to sow the fewest acres of corn in four years. The USDA also said corn stockpiles were roughly 7 billion bushels, a rebound of 30% from a year earlier, but missing expectations.

Milk futures ended the month near an all-time high as surging U.S. dairy exports depleted supplies. Investors don't expect prices to fall anytime soon since the U.S. Dairy Export Council, a trade group, suggests China's appetite for imported milk could more than quadruple by 2020.

Gold fell in March after U.S. economic data beat estimates and Federal Reserve chief Janet Yellen said the central bank's bond-buying program could end this year and interest rates could climb as soon as 2015.

“With geopolitical tensions not escalating further, with U.S. economic data starting to come in good, and with expectations of a continuing tapering by the Fed resurfacing, people now seem to have started reducing their bullish exposure in the yellow metal,” Abhishek Chinchalkar, an analyst at Mumbai-based Anandrathi Commodities LTD., said in a report.

Despite the drop, the precious metal has still gained more than 7% this year, reaching a six-month high as Russia's annexation of Crimea ignited demand for a safe haven.

Follow Julie VerHage on Twitter @julieverhage.