The crop reached black layer at all locations during the past two weeks. Therefore, Sept. 10 projections give final estimates of yield potential for dryland and irrigated corn for the 2012 crop season.

  • Predicted yield potential is below the long-term average at all sites, under both irrigated and dryland conditions.
  • For dryland corn, there is a modest yield loss (6-18%) for the locations in South Dakota (Brookings) and west-central and north-central Illinois (Monmouth and DeKalb) while a moderate yield loss of 22-30% is predicted for dryland corn in central and northeast Iowa (Gilbert and Nashua).
  • Severe yield loss of 32-67% is projected for dryland corn in south-central, eastern and northeast Nebraska (Clay Center, Mead, and Concord), northwest Iowa (Sutherland) and south-central Illinois (Bondville).
  • In contrast to the large loss of yield potential in these dryland systems, projected losses in yield potential at all irrigated sites are modest at 3-5% in south-central Nebraska (Clay Center, Holdrege), and 7-8% in east and northeast Nebraska (Mead, O’Neill, Concord).

The bottom line is that 2012 irrigated yields will be moderately lower than the long-term averages (3-8% below normal), while dryland corn yield potential in much of the Corn Belt will be moderately to severely reduced (22-67% below normal). Keep in mind that yields of both dryland and irrigated corn can be even lower at places where:

  1. High temperature stress occurred at pollination
  2. Irrigated systems were unable to keep up with crop water use demand or there were problems with pivot irrigation nozzles and uneven watering
  3. There were additional stresses from insects and diseases
  4. The initial soil moisture profile at planting was below 100%, as assumed in these corn simulations

Indeed, in many places in Nebraska soil moisture at planting was below full recharge due to a drier than normal winter-spring season. In these areas dryland yields would be reduced below the estimates in Table 1.


Patricio Grassini, Research Associate Professor, Agronomy and Horticulture Department

Jenny Rees, UNL Extension Educator

Haishun Yang, Associate Professor, Agronomy and Horticulture Department

Kenneth Cassman, Professor, Agronomy and Horticulture Department


Link to a larger version of Figure 1 and Table 1.