The nation’s corn harvest will be about 0.2 percent smaller than the government projected last month, while the crop’s yields are on track to drop to a six-year low, according to a survey of grain analysts.

About 12.4 billion bushels of corn will be harvested this fall, based on the average estimate in a survey of 22 analysts conducted by Dow Jones Newswires ahead of the U.S. Department of Agriculture’ next Crop Production report, scheduled for release Nov. 9 at 7: 30 a.m. Central time.

The average estimate is down about 30 million bushels from the 12.43 billion bushels the USDA estimated a month ago and would be down 0.6 percent from the 12.46 billion bushels harvested in 2010. The projected harvest would still be the fourth-largest on record.

Harvest prospects deteriorated since spring after wet conditions delayed corn planting for many Midwest farmers beyond the ideal time frame and a July heat wave coincided with the crop’s critical pollination phase.

“The trade is strongly convinced that the USDA will leave steady or lower (its) corn production estimate,” Dallas Landt, an analyst with R.J. O’Brien & Associates, said in a report earlier this week.

Based on the Dow Jones survey, the corn crop is expected to generate an average yield of 147.9 bushels an acre, down 0.2 bushel from the USDA’s October estimate and down nearly five bushels from the 2010 average. The estimated yield would be the lowest since 2005, when the crop also averaged 147.9 bushels an acre.

The USDA will also update its monthly Supply and Demand updates at the same time Nov. 9.

Grain traders and analysts will examine the reports closely to ascertain whether corn will continue a recently upswing that’s sent Chicago futures up nearly 11 percent from seven-month lows reached in late September.

In trading Nov. 4, corn futures for December delivery rose 2 ¼ cents to $6.55 ¾ a bushel, up from a settlement of $5.92 ½ on Sept. 30. July futures rose 3 cents to $6.78 ¼. In June, corn touched $7.99 ¾, an all-time high for a contract closest to expiration.

If the USDA reports are bullish, a rally to $6.75 in December corn futures “is possible,” Rich Feltes, another R.J. O’Brien analyst, said in a Nov. 3 report. Feltes added, however, he would view such a scenario as “selling opportunity.”

For livestock feeders and other corn buyers, the USDA reports likely will reinforce an outlook for historically tight grain supplies and high feed costs.

The USDA is expected to cut its estimate for corn stockpiles at the end of the 2011-12 marketing year in August to about 801 million bushels, a decline of about 7.5 percent from last month’s estimate, according to the survey. So-called ending stocks would be down percent from 2010-11 levels and the lowest amount of corn on hand prior to a new harvest since 1996.

U.S. farmers are expected to harvest 3.06 billion bushels of soybeans, according to the Dow Jones survey. That’s unchanged from the USDA’s October estimate, but down 8.1 percent from the 3.33 billion bushels harvested in 2010.

Soybean yields are expected to average 41.5 bushels an acre, also unchanged from the USDA’s October figure. Yields averaged 43.5 bushels an acre in 2010.