CHICAGO, March 19 (Reuters) - Chicago Board of Trade (CBOT) wheat and corn prices strengthened on Tuesday on technical moves as traders seek to unwind short positions ahead of uncertain springtime weather and upcoming U.S. Department of Agriculture reports, analysts said.

Soybeans were little changed, capped by hefty South American supplies and decreased Chinese appetite for U.S. soy.

"We’ve had a nice rally as we’re getting near to risk season," said Jim Gerlach, president of Indiana-based A/C Trading, referring to uncertain U.S. springtime weather. “Now we’re at a point of market equilibrium. Things were so over-sold in February, but that doesn't mean we're transitioning into a bull market."

The most-active wheat contract on the Chicago Board of Trade (CBOT) was up 7-3/4 cents at $5.50-1/2 a bushel by 11:32 a.m. CDT (1632 GMT).

Benchmark wheat had jumped 2.7% on Monday to pull away from last week's 3-1/2 year low, as news of Russian attacks on the Ukrainian port of Odesa revived worries about war disruption to massive grain exports through the Black Sea. Huge supplies of cheap Russian wheat continue to hang over the market.

Rising wheat prices and potentially unfavorable weather in the U.S. Corn Belt are working to lift corn prices, according to traders.

CBOT corn was up 3 cents at $4.39 a bushel while soybeans were down 1 cent to $11.86-3/4 a bushel.

Strong corn and soy crops in South America will keep prices anchored, but concerns over dry weather in Brazil and the U.S. Midwest are prompting short covering, analysts said.

Traders are also adjusting their positions ahead of the USDA's March 28 Prospective Plantings and quarterly stocks reports, which have a history of jolting markets.

A rise in the dollar index curbed Chicago futures by making U.S. grain more expensive overseas. The greenback strengthened ahead of the Federal Reserve's latest outlook for rates on Wednesday.

Like wheat, corn and soybean futures have hit three-year lows in the past month.

“Overall we’re not doing anything too terribly exciting, and it's a little bit of a holding pattern," Matthew Wiegand, consultant at FuturesOne, said.

(Reporting by Heather Schlitz in Chicago. Additional reporting by Gus Trompiz in Paris and Peter Hobson in Canberra; Editing by Subhranshu Sahu, Rashmi Aich, Shweta Agarwal and Aurora Ellis)