U.S. grain and oilseed futures ended mostly lower Wednesday as traders took profits on long positions amid already high prices and a lack of fresh news.

Corn, wheat and soybeans all traded slightly lower for most of the day. While traders are worried about crops and tight supplies in all three markets, they said that a lot of that worry has already been priced into the market.

The market is "kind of betwixt and between" at the moment, with the production worries tempered by lousy demand, said Jack Scoville, vice president for Price Futures Group. Prices are already high, traders added.

"I'm not bearish, but at $7.50 [for corn], how bullish do I really have to be?," Scoville said.

Scoville and other traders noted that $7.50 barrier, as well as $14 per bushel in soybeans, as being overhead resistance that would be tough to overcome, at least in the near-term.

Corn for September delivery at the Chicago Board of Trade climbed 1 1/2 cents, or 0.2%, to $7.31 3/4 per bushel, while December, the most-active contract, slipped 1/2 cent to $7.43.

Soybeans for September delivery slipped 3 cents to $13.86 1/2.

There was profit-taking across the grains and oilseeds complex, as "the prices really in all three [trading] pits met intermediate chart objectives," Farm Futures analyst Arlan Suderman said.

Traders are watching results from the Pro Farmer crop tour this week, which is generally finding disappointing corn crops and, to a lesser extent, soybeans. Some traders said the crop troubles have already been priced in, however.

Farmers are now equipped with smart phones that take photos, Suderman noted, which is helping to distribute information about the crop sooner.

"A lot of those pictures made their way to the trading floor," Suderman said.

Still, projected supplies seem to be shrinking more quickly than demand, which has contracted as prices have held at historically high levels, analysts said.

The Pro Farmer tour will release results of its Illinois corn and soybean survey this evening.

Traders are wary of outside market, including equities, which had provided support to the market recently until Wednesday. A couple analysts said they were concerned that the outside markets were pricing in expectations that Federal Reserve Chairman Ben Bernanke would announce steps to stimulate the economy in a Friday speech, and if that does not happen, a slump in financial markets could drag commodities lower as well.

Wheat prices declined Wednesday, led by the MGEX market, which fell on pressure from the spring wheat harvest, which is pushing more supplies into the pipeline.

MGEX September wheat fell 24 1/4 cents, or 2.6%, to $9.26 a bushel, while Kansas City Board of Trade wheat fell 6 cents to $8.35 and CBOT September wheat slipped 8 cents to $7.49 1/4.

Other markets fell as well, including CBOT oats, which slipped 4 1/4 cents to $3.60 1/4 and CBOT rice, which fell 11 cents to $16.85 1/2.