Corn's gain was soybeans' and wheat's loss.

OK, the dynamics of the Chicago market weren't quite that simple on Monday. But nor was it a co-incidence that corn managed a positive close – its second in three sessions, even – while its peers went back to their old closing-lower ways.

With the dust settling somewhat after a two-week rout, since the US Department of Agriculture came up with a set of bearish crop estimates, investors appear to have begun taking a more sophisticated view again, beyond simple panic selling (or greedy short-covering for the lucky ones).

Taking out a spread by buying corn - arguably the least vulnerable of the big three to further price reductions because of relatively tight supplies - and selling one of the other crops has emerged as a popular theme.

Spreads spread

"Spreading of corn/wheat helped keep corn higher at the close while contributing to the sell off in wheat," Vic Lespinasse, the GrainAnalyst.com analyst, said.

At broker Country Futures, Darrell Holaday said: "There is a lot of corn/soybean spreading developing today."

But that wasn't the only thing which left soybeans down 1.2% at $9.40 ½ a bushel for March at the close, its lowest finish since early October.

The earlier concerns about Argentine drought dried up, giving way to more robust forecasts for Brazil's crop, with analysis group Agroconsult the latest to say it might revise upwards its estimate for the harvest.

"Conditions continue to improve in South America and production numbers continue to creep up," Mr Holaday said.

Export prospects

Meanwhile corn, which ended up 3 cents at $4.67 ¾ a bushel for March, was also helped by a bounce in the oil price, an important indicator for a crop so popular in making bioethanol.

Crude stood 1.0% higher at 10:00 GMT.

And wheat didn't do so bad, considering it was on the wrong side of spread positioning and is troubled by the everpresent richesse of global supplies.

Chicago's March lot ended down a mere 0.25 cents at $4.98 ¼ a bushel.

There is some evidence that its fall of 13% or so over the last fortnight has done some good for wheat's export prospects, with official data on Monday showing US export inspections of 16.9m bushels, considering better than the 10m-13m bushels traders had expected.

Ukraine slowdown

Furthermore, exports from Ukraine are slowing down after setting a cracking pace at the start of 2009-10.

But, as Agrimoney.com and others have warned, it hasn't got sufficient crop to keep going like that all season, and a slowdown in Ukraine's bargain basement shipments might give higher priced rivals a chance.

Indeed European wheats took a little bit of cheer, with London's May contract, at least, adding all of £0.10 to end at £103.75 a tonne.

Paris wheat for May closed up E0.75 at E129.50 a tonne.