Chicago wheat edged higher on Tuesday to add to sharp gains a day earlier as the market assessed the risk of yield losses to U.S. crops due to a combination of dry and cold weather.
Corn was slightly lower, with traders digesting news that China is to scrap its stockpiling scheme for the grain, a move that could curb imports.
Soybeans were almost flat in subdued trading, with many investors looking ahead to Thursday's U.S. planting and stocks estimates from the U.S. Department of Agriculture (USDA).
The most active wheat contract on the Chicago Board of Trade rose 0.3 percent to $4.72-1/2 a bushel, after closing up 1.7 percent on Monday when prices hit a two-week high of $4.77-1/4.
Weather forecasts suggested dry conditions would persist in the southern U.S. Plains, a key zone for hard red winter wheat production, while other areas have seen chilly temperatures.
The weather risks have tempered bearish sentiment about large inventories and slow exports.
"Investors more than likely have the view that U.S. wheat supply is heavy," said Tobin Gorey, director of agricultural strategy at Commonwealth Bank of Australia. "We'd largely agree but the dodgy weather in the U.S. hard red wheat region has the potential to erase the worst part of that outlook," said Gorey.
A weekly Commodity Futures Trading Commission report last week showed large speculators expanded net short positions in CBOT wheat to 127,479 contracts in the week ended March 22.
The most active corn futures contract inched down 0.1 percent to $3.70-1/4 a bushel. Soybeans ticked up 0.2 percent to $9.10-3/4 a bushel.
China plans to scrap its giant corn stockpiling scheme and allow markets to set prices for the grain, the State Administration of Grain said in a statement on Tuesday.
China imports much less corn than soybeans but a decline in its overseas buying could a bearish signal, analysts said.
"In an amply supplied market with record-high global stocks ... a few million tonnes could nonetheless be sufficient to put further pressure on the world market price," Commerzbank analysts said in a note.
Traders were also turning their attention towards Thursday's USDA spring planting estimates, which will be released alongside quarterly grain stocks data.
Analysts, on average, expected the USDA to report a jump in corn and soybean seedings over last year, despite three years of falling prices.