Agricultural commodity bulls had at least two factors in their favour on Thursday.

The first was a better mood on external markets, fostered not least by ideas that Chinese officials may act to support stocks, after Shanghai shares fell to their lowest since February 2009.

Shanghai stocks bounced 2.5%, while the more risk-on attitude was evident too in small rises in London copper and Brent crude, and a decline in the safe haven of the dollar.

'$5.00-a-bushel corn'

The second was a growth in gloomy talk which often heralds rising prices, just as undue exuberance is often a sell sign.

At Market 1, Mike Mawdsley talked of investors "throwing in the towel". Capitulation often precedes fresh buying.

And Richard Feltes at RJ O'Brien noted that he was "hearing more chatter about $5.00-a-bushel corn and $12.00-a-bushel soybeans latter next year if both crops transition to more adequate supplies".

Those are below the outlooks even for Societe Generale, one of the more bearish commentators, which foresees corn dropping to some $6 a bushel by the third quarter of 2013, and soybeans to a little under $14 a bushel.

And, while not out of the question, they are far cries from the ideas of $20-a-bushel soybeans and $9-a-bushel corn that investors have been told from many other brokers are in sight.

Value levels?

Another factor potentially in bulls' favour was the prospect of key US Department of Agriculture due on Friday, on US crop inventories as of the start of the month.

While not expected themselves to be particularly upbeat (or easy to analyse, with the early harvest mixing new crop with old) the prospect of a surprise could cause investors to tread carefully ahead of the briefing.

And there was a widespread shout that corn and soybean futures were "oversold" given the speed of the declines which have taken prices some $1.20 a bushel and $2 a bushel respectively below summer highs.

There was also even talk of prices reaching fundamentally attractive levels for buyers.

"I believe the corn market is trading near levels at which the commercial buyer/end-user can find value," Brian Henry at Benson Quinn Commodities said.

'Immune to informed estimates'

However, there was a caveat.

"I am not sure that the fund has liquidated enough length to solve the problems that have been presented by the recent weakness," Mr Henry said.

RJ O'Brien's Richard Feltes went further on the extent of negative thinking among investors, over corn at least.

"The corn market appears immune to informed estimates that the final US corn yield will slip below 120 bushels per acre, preferring instead to agonise over further liquidation of the large fund long position, dismal export sales, anaemic ethanol margins and negative chart action," he said.

"Fundamentally, the soybean market, not corn, should be the first to bottom."

'Harvest low soon'

And the idea of a bottom is a pertinent one, given the ageing of the harvest which is weighing on prices as buyers find farmers willing to sell straight off the combine, and with better-than-expected soybean yields creating more supplies than many growers been bargained on.

"Some are looking for a harvest low soon," Market 1's Mike Mawdsley said, with the first week of October seen as a typical one for soybeans.

"It usually doesn't happen until we get into October or near 75% completion with harvest, which we are close to."

Chicago prices

Still, it was soybeans which indeed outperformed corn in early deals, standing 0.4% higher at $15.79 ¼ a bushel at 09:10 UK time (03:10 Chicago time) for November delivery.

Signally, that was just enough to take the lot back over the 100-day moving average, on a continuous chart, below which it closed the last session for only the second time since January.

Corn for December remained in negative territory, although it managed some rebound from an early low of $7.21 ½ a bushel, the weakest for a spot contract since early July, to stand at $7.23 ½ a bushel a decline of 0.2%.

Wheat did best of all, adding 0.6% to $8.74 ¼ a bushel.

Technically, "the wheat market has not yet breached the low side of the recent range, which at this point is still a supportive factor", Benson Quinn's Brian Henry said.

Palm down

The brighter mood had yet to carry palm oil, which stood 1.0% lower at 2,591 ringgit a tonne in Kuala Lumpur for December delivery, setting a two-year bottom earlier of 2,569 ringgit a tonne.

"Palm oil stocks in number-two producer Malaysia look set to climb higher on strong production, and while exports rose from a month ago, traders said the increase was not enough to bring down high inventory levels, which hit a 10-month high in August," Ker Chung Yang, at Phillip Futures, said.

Furthermore, the technical damage done to the vegetable oil's charts by this week's collapse has only dissuaded buyers yet from taking advantage of the lower prices.

New York revival

But New York soft commodities did a better job of trapping tailwinds.

Raw sugar for October added 0.3% to 19.63 cents a pound, although with the expiry process imminent, there is some caution over the contract, with some believing it will witness hefty physical deliveries.

Of note was that China set a sugar import quota of 1.945m tonnes for 2013, unchanged from this year, and despite richer domestic supplies.

New York cotton for December added 0.1% to 71.12 cents a pound.