The wide soybean price swings reflect ever-changing supply-and-demand expectations, according to Darrel Good, a University of Illinois agricultural economist. "November 2012 soybean futures reached a high of $14 in September 2011, declined to about $11.20 in December 2011, rebounded to almost $14 in early April and again in early May 2012, and traded to a low of $12.45 in the current trading session," Good says.

"Much of the strength in soybean prices during the first three months of this year reflected deteriorating production prospects in South America," Good adds. "The USDA currently projects production in five South American countries at 4.237 billion bushels, 779 million bushels (15.5%) smaller than the 2011 harvest and 833 million bushels (16.4%) smaller than the December 2011 forecast. Some believe the crop to be even smaller."

Good says the USDA will provide an updated estimate on June 12. Much of the price weakness over the past few weeks reflects growing concerns about the U.S. and world economic and financial conditions and the negative implications for commodity demand. Prices will continue to be influenced by a wide range of factors, but over the next three months, prospects for the 2012 U.S. crop will be one of the more important factors.

"The USDA's March 30 Prospective Plantings report revealed producer intentions to plant 1.074 million fewer acres this year than planted last year," Good says. "The USDA will release an estimate of planted and harvested acreage on June 29. The strong soybean price rally into planting time suggests that acreage may exceed intentions. Unless there is a large difference from intentions, the production focus will be primarily on yield prospects."

Good says it's too early in the season to form specific yield expectations.

"The long-term trend yield calculation for 2012 is 43.4 bu. The USDA's early projection of yield potential is 43.9 bu., and the record yield was 44 bu. in 2009.

"One factor that should support yield potential is the small percentage of the crop planted late this year," Good says. "Late planting can be characterized in a number of ways since production occurs over a large geographic area, planting occurs over a period of several weeks, and planting has generally occurred earlier over time.  We have defined late planting as the percentage of the crop planted after May 30 in the major soybean-producing states included in the USDA's Crop Progress report. Based on that definition and weekly planting progress reported by the USDA, we estimate an average of 34% of the crop was planted late in the 26-year period from 1986 through 2011."

Good reports that the smallest percentage planted was 13.6% in 2000. Some of the late planting each year reflects soybeans planted following winter wheat harvest.

"Only 11% of the crop was reported as not yet planted as of May 27 this year, so a new record low percentage of the crop was planted late this year," Good says. "With an early harvest of the soft red winter wheat crop, even most double-cropped soybeans will be planted in a timely fashion. Timeliness of planting is not the most important factor in determining yields, but an early-planted crop suggests a higher yield potential than if an average percentage of the crop had been planted late."