Results and Discussion
Environmental conditions varied among the 2009 and 2010 growing seasons at the
University of Illinois Crop Science Research and Education Center in Urbana, Illinois. The most notable difference was July and August rainfall in 2009 which was 37 and 39 mm above the twenty year average (Table 4). Comparatively, July and August rainfall in 2010 was 28 and 58 mm, respectively, below the twenty year average. Temperatures, versus rainfall, were more similar between the 2009 and 2010 growing seasons. July and August temperatures were 2.4 and 1.5° C, respectively, cooler than the twenty year averages in 2009, and 1.5 and 2.2° C, respectively, warmer than the twenty year averages in 2010 (Table 4). Although 2009 brought higher than normal July and August rainfall and cooler than normal temperatures, soybean yields were similar to the twenty year averages at 3094 kg ha-1(USDA NASS, 2011). Environmental conditions in 2010 were also favorable for normal soybean growth and development and the highest average yields to date were reported for the state of Illinois at 3463 kg ha-1
(USDA NASS, 2011).