ARS | Publication request: Winter Canola as a Rotation Crop in the Low and Intermediate Precipitation Zones

Submitted to: Washington State University College of Agriculture and Home Economics
Publication Type: Abstract Only
Publication Acceptance Date: August 20, 2008
Publication Date: August 20, 2008
Citation: Schillinger, W., Kennedy, A.C., Paulitz, T.C., Young, D., Smith, T. 2008. Winter Canola as a Rotation Crop in the Low and Intermediate Precipitation Zones. Page 23. . Washington State University College of Agriculture and Home Economics.

Technical Abstract: Multiple-year experiments are being conducted in the low and intermediate precipitation regions to document the rotation benefits of winter canola (WC) in wheat-based cropping systems. Farmers in both the low and intermediate precipitation zones have reported economically viable winter canola yields. In addition, some farmers have reported that the winter wheat (WW) crop following winter canola often has less disease and weed pressure and produces considerably higher grain yield compared to monoculture winter wheat in the traditional 2-year WW-summer fallow (SF) rotation or spring cereal (either wheat or barley) in the 3-year WWSW-SF rotation. Additionally, it has been observed that water runoff from frozen agricultural soils does not occur following a winter canola crop, presumably because the deep tap root provides open channels for water to penetrate through the frozen surface soil layer. Neither the boost in subsequent wheat grain yield or the soil physical, biological, or pathological factors, that may account for better water infiltration and increased wheat yield as affected by having winter canola in the crop rotation have been documented. In the low-precipitation zone on Ron Jirava’s farm near Ritzville, we are comparing the 2-year WW-SF rotation to a 4-year WC-SF-WW-SF rotation. In the intermediate precipitation zone on Hal Johnson’s farm near Davenport, a 3-year WC-spring wheat (SW)-SF rotation is compared to WW-SW-SF. We will determine the effects of having winter canola in the rotation on soil microbial changes, water infiltration into frozen soils, plant health of the wheat crop following winter canola, winter wheat grain yield, and farm economics compared to checks (i.e., rotations without WC in the rotation). The scientists involved in this study are a research agronomist, soil microbiologist, plant pathologist, and agricultural economist. Three rotational years of data will be obtained from each site.