Evaluating the Suitability of Spring Canola in An Alternative Cropping System in Iowa.

Evaluating the suitability of spring canola in an alternative cropping system in Iowa Stefans R. Gailans and Mary H. Wiedenhoeft Spring canola (Brassica napus) is a productive oilseed crop that may be an alternative to soybean [Glycine max L. (Merr.)] in Iowa. A specialty oilseed processing facility in northwest Iowa provides a viable market for growers of non-genetically modified (GM) canola in the Midwest. Double cropping spring and winter crops can serve to extend the duration the ground is covered with actively growing vegetation. Sole-cropped soybean (SS) as well as double-cropped spring canola + winter wheat (Triticum aestivium L.; SC+WW) were grown to test these hypotheses. Grain and oil yield of soybean and spring canola were evaluated. Additionally, amount and duration of incidental photosynthetically active radiation (IPAR) interception of the two systems were compared. Oil yield of spring canola was twice that of soybean. Duration of IPAR interception was greater in the SC + WW system compared to the SS system. Results from this study indicate that the SC + WW system may prove to be economically and ecologically advantageous. Moreover, these results suggest the general potential of an alternative cropping system on the contemporary Iowa landscape.