* Soybeans rise, corn eases as acreage report looms
* Weak crude oil, firm dollar weighs on corn
* Wheat follows corn lower in thin trading
* Coming up: USDA acreage, quarterly stocks report Thursday (Recasts with U.S. market opening, adds quotes, detail, changes dateline from HAMBURG, adds byline)
By Karl Plume
CHICAGO, March 30 (Reuters) - U.S. soybean futures rose for a second straight day on Wednesday and corn eased ahead of a government report which was expected to show that U.S. farmers will plant more corn and less soy this year.
Weak crude oil and a firmer U.S. dollar further weighed on corn and pressured wheat.
But trading was choppy and volume was lighter than normal as investors squared positions before the U.S. Agriculture Department releases its eagerly awaited prospective plantings and quarterly grain stocks reports early on Thursday.
"People are just evening up their positions and not getting too ambitious in changing a position this close to the report," said Shawn McCambridge, analyst with Prudential Bache Commodities.
"That (weak crude and firm dollar) has some psychological bearing on the market right now, but it really comes down to the overall uncertainty with the reports tomorrow," he said.
The USDA report on Thursday will provide a much-anticipated forecast of which grains U.S. farmers are likely to plant this spring and is likely to be critical for wheat, corn and soybean price development.
Analysts on average expected corn seedings at 91.839 million acres, slightly below the USDA outlook forum projection of 92 million but well ahead of the 88.192 million acres seeded last year.
Soybean acreage was estimated at 76.87 million, below the USDA outlook's 78 million forecast and less than last year's soy acreage of 77.404 million.
USDA's quarterly stocks report was expected to show slight increases in March 1 U.S. wheat and soybean stocks from a year ago and a steep decrease in the corn supply.
Chicago Board of Trade CBOT May corn futures fell 1 cent, or 0.1 percent, to $6.70-3/4 by 10:28 a.m. CDT (1528 GMT), while May soybeans rose 10 cents, or 0.7 percent, to $13.71-1/2 a bushel.
"People are buying soybeans and selling corn, they've been doing this for the past three days. They think there may be bigger corn stocks than expected in tomorrow's report and they're looking for big corn acres and smaller soybean acres," said Roy Huckabay, analyst for The Linn Group.
CBOT May wheat fell 4-1/2 cents, or 0.6 percent, to $7.32-3/4 a bushel. EU benchmark wheat futures in Paris followed U.S. wheat down, with the May dropping 1.75 euro or 0.7 percent a tonne to 238.75. (Additional reporting by Michael Hogan in Hamburg, Zheng Xiaolu in Beijing; editing by Jim Marshall)