U.S. soybeans fell again on Wednesday, pulling back from their recent rally sparked by concerns over serious rain damage to Argentina's crop, while corn touched a one-week low on selling pressure.

Wheat moved in and out of positive territory on bargain-hunting after Tuesday's two-week low.

"Soybeans are again seeing selling pressure from investment funds today after touching 15-month highs this week, although selling is not so intensive as on Tuesday," said Frank Rijkers, agrifood economist at ABN AMRO Bank. "Corn is also being weakened by selling after price firmness in the past week or so." "Wheat is being supported by technical bargain-buying and short-covering after Tuesday's falls. But the wheat market is still weighing up the latest positive reports about the state of wheat from the U.S. crop tour and has been moving in and out of positive territory today."

Chicago Board of Trade July soybeans fell 0.4 percent to $10.25-3/4 a bushel at 1007 GMT. July corn fell 0.6 percent to $3.77-3/4 after touching $3.76-3/4 a bushel, the lowest since April 25.

July wheat fell 0.1 percent to $4.70-1/4 a bushel, after touching its lowest since April 18 on Tuesday.

Soybeans have surged since mid-April on worry that rains had ruined a significant part of Argentina's soybean crop. The country lost an estimated 9 million tonnes of soybeans due to April downpours.

Crop forecaster Informa Economics on Tuesday lowered its Argentine and Brazilian soybean crop forecasts.

"The soybean market is taking a breather after the massive price rises seen recently to 15-month highs as concern grew about weather damage to the Argentine soybean crop," Rijkers said. The market is pausing, waiting for further news about crop prospects in Argentina."

"We need more news before deciding whether the upside move has been broken." Crop scouts starting the annual tour of hard red winter wheat in the U.S. grains powerhouse Kansas projected an average yield of 47.2 bushels per acre in north Kansas, up from tour findings of 34.3 bushels last year.

"The initial assessment from the U.S. crop tour gave a good picture of wheat yields in Kansas, which is a bearish factor," Rijkers said. "But the mood in wheat has been swinging around between positive and negative today as the focus switched between the bearish outlook for a good U.S. crop against the attraction of bargain buying after the price strength in the past week."