Some observers identified fresh "long
On Thursday, there was a hint of the opposite dynamic at work, with grains holding the lead, if a slender one.
Soybeans were not helped by data overnight showing Chinese factory activity shrinking for a fifth month, according to an HSBC index, which came in with an activity index of 48.1, down from 49.6 in February. Any figure below 50.0 means shrinkage.
China is the top importer of soybeans.
The data from the world's top metals consumer sank
The news from China wasn't all negative, for crops at least, with the commerce ministry forecasting a jump to 5.1m tonnes in soybean imports this month, from 3.8m tonnes in February, if with a drop back to 3.9m tonnes forecast for April.
Furthermore, there is still talk of China having purchased reasonable quantities of US soybeans (two-to-four cargoes) earlier in the week.
This at a time when South America should be taking over, if it had been enjoying a decent enough harvest to depress local prices much, besides industrial action by lorry drivers.
"China is likely to buy US soybean as Argentina faces strikes of road transporters," Agritel added
Soybeans also had the technical support of their 10-day moving average, at a little under $13.54 a bushel for Chicago's May contract, as resistance to declines.
The moving average was just about holding as of 08:15 GMT, when the May lot stood at $13.53 ½ a bushel, down 0.1% on the day.
Still, for technical factors, it was more a day about corn, which having surrendered most of its major moving averages, was down to its last big one – the 100-day, at $6.38 ½ a bushel for Chicago's May contract.
"If the 100-day doesn't hold tomorrow, funds may do more selling," Mike Mawdsley at Market 1 said, adding that the next key chart point below looked at $6.32 a bushel, and an uptrend line extrapolated from the grain's last two nadirs.
"This needs to hold, or more fund liquidation may hit the pits this week."
And, at Benson Quinn Commodities, Jon Michalscheck restated ideas that options expiry may be behind liquidation on the first three days of the week which are estimated to have seen funds sell 38,000 corn contracts.
"I still believe at least a portion of this technical correction is due to the April options expiring this Friday," he said.
There are some 9,800 contracts still open at the $6.50 a bushel level, down 200 since Monday, and with the next largest chunk of open lots at $6.40 a bushel, with 3,238.
He added: "The fact that the Chinese have failed to buy additional US corn tonnage and that fact that a large majority of the central country is experiencing nearly ideal weather for this early in the year could be that is weighing on the market as well as the options expiring".
Indeed, news that China bought 350,000 tonnes of Australian feed wheat, for June and July delivery, continued to stalk the market.
As did the weather conditions.
"Unusually warm weather is prompting early fieldwork for farmers and talk of planting," Lynette Tan at Phillip Futures said.
"Earlier planting is seen as setting the stage for better yields, and could prompt farmers to plant more corn than initially expected."
What helped corn was something of a self-fulfilling dynamic of the May contract failing in early deals to look like busting through its 100-day moving average, standing at $6.42 a bushel, unchanged on the day.
Furthermore, there were plenty holding a candle for China yet to turn up as a buyer of US wheat.
The arbitrage to Chinese buyers of opting for US corn, rather than local supplies, on a September basis "has opened from what I see at least $5 a tonne in the last two or three sessions", Scott Briggs at Australia & New Zealand said.
"It's now at a $60-65 a tonne profit for reserve grain buyers," which can avoid VAT.
Corn prices in China itself fell overnight, by 0.4% to 2,465 yuan a tonne for the best-traded September contract on the Dalian exchange.
Back in Chicago, wheat gained 0.1%, to $6.37 a bushel, helped not just by firmness in corn (to which it stands at an atypical discount) but also by some concerns for the US crop.
While hard red winter wheat has received "valuable rain" in Oklahoma and southern Kansas, the southwestern Great Plains has escaped, Gail Martell at Martell Crop Projections said.
Dodge City in Kansas state, for instance, "continues to struggle with drought, receiving just 3.9 inches of rain in 90 day, 30% of normal.
"It is a reminder that hard red winter wheat conditions have not improved everywhere."
Besides there is some frost around too, although winter wheat "has not yet begun jointing so lasting damage is not expected", Ms Martell said, if adding that "leaf burn likely has occurred, setting back crop development".
Furthermore, much of western Europe is still unduly dry too, a matter which has been reflected in some recent outperformance in European wheat futures.
How contracts perform later, however, may depend largely on US weekly export sales data which are expected to improve for wheat to 400,000-500,000 tonnes, from 360,000 tonnes last time.
For corn, sales are expected at best to match the previous week's 836,000 tonnes, potentially coming in as low as 650,000 tonnes.
Soybeans are expected to see a drop to 400,000-1.0m tonnes, from 1.4m tonnes last time.
A (second successive) good figure might turn up in
"The market is keenly awaiting tonight's US weekly export sales report in order to gauge the current level of global cotton demand," he said.
"It is likely sales picked up in the week ending March 15 given prices fell to their weakest levels in three months."
New York cotton for May stood at 88.36 cents a pound on Thursday, up 0.1%.
"Prices closed near their session lows last night, suggesting the recent rally, up 12.5% in seven sessions, may have run its course," Mr Mathews said, also flagging a weakening in the premium of London white sugar over New York raws.