U.S. soybean futures bucked early profit-taking pressure and rallied to a three-week high on Wednesday on tight U.S. supplies and a stronger cash market.
Wheat shed earlier weather-fueled gains, overcome by technical selling and spillover pressure from a higher dollar and lower outside markets.
Corn futures ended mixed. Profit-taking pressured old-crop values, but new-crop corn contracts gained as the heavy rains across the Midwest grain belt delayed spring planting.
The turnaround in soybeans came amid concerns that export loading delays in South America could steer some global demand to the U.S., where supplies are projected to shrink to a nine-year low ahead of the autumn harvest.
Demand from domestic soybean processors also remains strong, with cash basis levels at several Midwest locations at the highest levels since August.
"Soybean supplies are still generally tight and we're still not turning off demand as quickly as we need to," said Rich Nelson, chief strategist with Allendale Inc.
New-crop soybean values ended flat to slightly lower as rainy weather around the Midwest further stalled corn planting, which could result in a shift to more soybean acres.
"Rains of two to 4.5 inches are expected through Friday in the Plains and central Midwest, and another snowstorm is expected from western Nebraska into central and southwest Minnesota," said Commodity Weather Group meteorologist Joel Widenor.
"This will limit corn seeding until the weekend, when the southern third of the belt should be able to see a couple days of fieldwork," he said.
Chicago Board of Trade (CBOT) May soybeans settled 10-3/4 cents higher at $14.22-1/4 a bushel, a 0.8 per cent gain, after rising as high as $14.29-3/4, a level not seen since March 28 (all figures US$). Buying accelerated above the contract's 100-day moving average near $14.25, but the rally failed to breach the 50-day moving average of $14.31.
New-crop November soybeans ended 1/2 cent lower at $12.18 per bushel.
CBOT May corn shed 2-3/4 cent to $6.60-1/2 a bushel after gaining more than 2.5 per cent in the previous session, the strongest rally in six months. Planting delays helped to lift new-crop December corn 7-1/2 cents, or 1.4 per cent, to $5.48-1/4 a bushel.
Wheat futures were higher for most of the day on worries that rain in the Midwest and a cold snap in the U.S. Plains could damage the developing U.S. winter wheat crop.
But the rally stalled under pressure from lower outside markets and a strengthening dollar, which makes U.S. wheat costlier for world buyers.
CBOT May wheat closed just 1/4 cent higher at $7.03-3/4 a bushel after earlier hitting a high of $7.15-1/2.
Kansas City Board of Trade May wheat also closed just 1/4 cent higher, settling at $7.42 a bushel after peaking at $7.54.
Both contracts peaked just 1/2 cent short of their Monday highs and failed to breach their 50-day moving averages.
-- Karl Plume writes for Reuters from Chicago. Additional reporting for Reuters by Sam Nelson.