First year field research was completed and published to the WSU Biofuels Cropping Systems web site (http://css.wsu.edu/oilseeds). Results were discussed at Palouse Conservation Farm, Lind, Puyallup, Prosser, and Wilke Field Days. A Washington State Interagency Renewable Energy Task Force organized a tour of renewable energy projects, including a stop at Prosser-IAREC, for politicians and other stakeholders to see the ongoing field research projects. An irrigated canola extension bulletin is published and switchgrass production bulletins are in review. Research has identified constraints, challenges and opportunities for sustainably producing biofuel crops in WA state. Summary of research findings to date include the following:
- Irrigated winter canola yields were > 2.5 T/acre, managed with deficit irrigation at Prosser, demonstrating the crop has high water use efficiency, potentially saving water and pump electricity costs. Furthermore, the crop matures quickly, allowing for the possibility of double cropping under irrigation, which would increase the seasonal land unit productivity. Oilseeds can be used in a deficit irrigation rotation, providing more water for the next crop (e.g. potatoes).
- Spring canola can be established in heavy residue (i.e. winter wheat) with wider row spacing than traditional row spacing, and yields the same or better than with narrow row spacing.
- Spring camelina grew best under conditions in which spring cereals grew well. Conversely, camelina yields were poor in areas in which spring wheat yields were also poor (Lind, WA). However, camelina trials have shown that it can yield adequately (up to 1 T/acre) following winter wheat in an intermediate rainfall zone.
- Significant progress has been made in developing non-GM, herbicide tolerant camelina germplasm, which would offer increased opportunities for weed control in cereal based rotations.
- Winter canola seedling establishment in the fall is undependably variable under dryland conditions of eastern Washington due to dry, hot soil conditions, limited growing degree days for late planting dates, and potential winterkill due to frost sensitivity. Varieties differ in their stress sensitivity. Deep furrow planting techniques used to plant wheat in the area do not work for oilseed crops. Early fall rains or drill modifications are needed to consistently establish canola in the fall in this region. Drill modifications are being made to move soil out of the furrow for more successful canola emergence.
- Other researchers have demonstrated true winter canola is a biennial, not an annual crop, which opens up opportunities for establishing a solid stand with developed root systems during the first season with a spring to mid-summer planting in an otherwise fallow season, perhaps graze the vegetation the first year, and then allow the crop to produce seed in the second season. Theoretically, stand establishment will be more successful, and yields will be higher and more stable. Use of an herbicide resistant variety would further allow for a modified chemical fallow-like rotation with this approach.
- Efficient water use by canola may be attributable to its deep root system and its root hair architecture.
- Nitrogen fertility trials in dryland and irrigated systems suggest that N recommendations may not be substantially altered by water availability within either system.
- Switchgrass can be successfully established in the Columbia Basin, potentially providing a significant feedstock source for cellulosic ethanol production.
- Through case study interviews we are learning that herbicide carryover is a huge concern in oilseed crop production (particularly in eastern Washington), with certain herbicide groups persisting for longer time periods than expected.
- Growers (and researchers) are learning how to use different types of canola (e.g. RR, CL, etc.) for better (superior) weed control in cereal based rotations, enabling more effective control of problematic weeds.
- Canola, mustard, camelina, flax, and sunflower can be successful alternative rotation crops in western WA, but managed in concert with Brassica seed production in the area.
Stakeholder and grower awareness of challenges and opportunities in transitioning cropping systems to include biofuel crops was increased through outreach activities described above. We have provided grower and industry educational workshops in support of a viable biodiesel production facility in Odessa, WA.