Soybeans headed for a strong finish to the week in Chicago, helped by yet further Chinese, while wheat toyed with setting a fresh 2009 low.
The signals from external markets were set to green, with shares rallying in Europe and New York - and oil too - on firm US homes and German industrial data.
Ben Bernanke, the chairman of the US Federal Reserve stoked optimism by saying that the "prospects for a return to growth in the near term appear good".
Soybeans seized the opportunity to regain some of the ground lost earlier in the week, helped by a fifth successive days of Chinese purchases of US beans which took the total to 896,000 tonnes in a week.
"This continued Chinese presence in our bean market should lend support to this pit," Vic Lespinasse, at GrainAnalyst.com, said at the start of live trading.
Traders also took as bullish the vote by Argentina's Congress and Senate to extend President Cristina Fernandez's term of power over grain export taxes.
Ms Fernandez is viewed as being somewhat keener on levying export taxes, particularly on soybeans, than farmers would like.
"This could renew [Argentine] farmers' protests and possibly disrupt Argentine bean and product exports, which would be bullish for US bean and product prices," Mr Lespinasse said.
Soybeans for September added 16.5 cent to $10.15 ¾ a bushel at 17:15 GMT, with the November contract up 11.75 cents at $9.68 ¾ a bushel.
Some nerves remained ahead of the release of ProFarmer's findings following its tour of Midwest corn and soybean crops. A tour report will be released later on Friday.
Soybeans' strength spilled over into corn, which added 2.75 cents to $3.21 ¼ a bushel for the September contract, and 1.75 cents to $3.25 ¾ a bushel for December.
However, there was no such luck for wheat, which faced some crop-specific headwinds.
One was a Canadian report showing farmers were expecting far more of their crop than analysts, or government statisticians. Another was a Rabobank report cutting its forecast for wheat prices into next year.
Chicago's September contract stood 8 cents lower at $4.61 a bushel, after touching $4.58 ¾ a bushel earlier, 1 cent from its 2009 low.
The December lot was 8 cents down at $4.88 ½ a bushel, after coming with 0.25 cents of its contract low.
Among softs, the optimism which buoyed shares and oil fed into the cocoa market, the idea being that stronger economic hopes hint at better chocolate consumption.
December cocoa added 1.6% to $2,961 a tonne in New York and closed 1.8% up at £1,882 a tonne in London.
However, sugar had a quieter day, without fresh dynamics to renew its upward path.
New York raw sugar for October was 0.8% lower at 21.79 cents a pound, while London white sugar slipped 0.5% to $553.3 a tonne.