Irrigated corn response over past 39 years
By Jerry Wright,
Associate Professor & Extension Engineer, University of Minnesota Extension
By Norm Krause,
Central Lakes College - Staples, Ag Center Director
Irrigation has been evaluated on field corn at Central Lakes College - Ag. Center (formerly known as Staples Irrigation Center) in Staples, Minnesota every year since the Center opened in 1969. Figure 1 shows the average yearly corn yields from dry land and irrigated plots grown on Verndale sandy loam soils at the Center as reported in the respective annual research reports from Central lakes AG Center and the University of Minnesota corn evaluation trials.
Irrigated corn yield over the past 39 years at the Center has averaged 144 bushels with a standard deviation of 24 bushels. Dry land over that same period of time averaged 66 bushels with a standard deviation of 38 bushels. The irrigated yields over the last ten years have averaged 169 bushels and 175 bushels over the past 5 years. Dryland has averaged 57 and 38 bushels for the same time period. Irrigated yield over the past 39 years has varied from less than 90 to slightly over 200 bushels in a few research plots while dryland yields have varied from 0 to over 150.
The irrigated yield shown for many years represents an average yield from several studies conducted at the Center by staff of the Central Lakes College and the University of Minnesota-College of Food, Agricultural and Natural Resource Sciences. Annual dryland yields shown were generally taken from selected plots at Ag Center but in some years data came from neighboring dry land fields when not available at the Center.
Yield data from 2007 U of M corn variety tests can be seen at University of Minnesota website: http://www.maes.umn.edu/08varietaltrials/.
Yield data from Central Lakes College - Ag Center's 2007 trials can be obtained by contacting Norm Krause at email@example.com or 218-894-5160.