As Figure 1 shows, the 2004 and 2005 corn crops in Iowa are the two highest yielding corn crops the state has ever seen. But producers had questions about both crops going into harvest. Precipitation was below average over both growing seasons and the 2004 and 2005 summers were at the extremes for temperature. In fact, since 1993, Iowa corn yields have not fallen below 120 bushels per acre. For the last eight years (counting 2005), state-average corn yields have exceeded 140 bushels per acre. While Iowa has not experienced a statewide drought or weather disaster over this period, the weather conditions have not been what is typically considered ideal for crop production
Hart, Chad E.
"Are We Underestimating Corn Production Potential?,"
Iowa Ag Review: Vol. 11
, Article 3.
Available at: http://lib.dr.iastate.edu/iowaagreview/vol11/iss4/3