"Wheat and soybeans are weaker as fear about poor crop weather is has fallen back today," said Matt Ammermann, commodity risk manager at INTL FCStone. "Corn is seeing some buying interest after its drop yesterday."
Market focus was turning to US Department of Agriculture (USDA) crop and inventory estimates on Friday, which are expected to show abundant global supplies of grains and soybeans.
Chicago Board of Trade March wheat was down 0.3 percent at $4.26-1/4 a bushel at 1120 GMT. It fell 0.9 percent on Monday pressured by lacklustre US export demand and higher temperatures in the US Plains.
March corn rose 0.2 percent to $3.48 a bushel after dropping 1.1 percent to $3.46-3/4 on Monday, the lowest since Dec. 19 and close to life of contract lows. March soybeans fell 0.3 percent to $9.63-1/2 a bushel, having fallen 0.4 percent on Monday.
"Wheat was supported last week by very cold weather in parts of US grain belts but US weather has now swung around 180 degrees and is rather warm," Ammermann said.
"This has removed some fear from prices today. Meanwhile, Black Sea region weather continues to be generally warm and Russian wheat exports continue to flow into world markets without major weather disruption."
Temperatures warmed up and rains arrived in parts of US southern Plains wheat areas, alleviating some concerns about damage to plants, before bitter-cold conditions return next week, according to the Commodity Weather Group.
"For soybeans, South American weather is also looking reasonable today without serious events visible in Argentina and Brazil which threaten soybean crops," Ammermann said. "Argentina is still dealing with some dry spots but enough rain remains there, while Brazil remains largely ok at the moment."
"Corn continues to see support at the $3.50 a bushel level which we fell through yesterday."
Chicago March corn dropped to a session low of $3.46-3/4 per bushel on Monday, just above its lifetime low of $3.46-1/2 last reached on Dec. 19.
"Overall markets are awaiting the USDA forecasts on Friday, which could be a reminder of large global supplies while the impact of slow US corn and soybean exports could also be seen in stocks," he said.