The Washington state Biofuels Cropping Systems (WBCS) Project was initiated in 2008 to provide research and extension leadership, coordination and government/industry linkages targeting the expansion of biofuel feedstock production in Washington State. An emerging demand for biofuel crop feedstocks is rapidly growing in the regional ground and air transportation fuel markets, and regional processing industries will require local feedstocks to be viable. Previous to this project, dryland agronomic research and extension programming at WSU over the past century has predominantly focused on cereal production in the region. The WBCS program uniquely focuses on implementing crop diversification and intensification by utilizing oilseed crops grown in rotation with cereals. With expanded crop choices, producers can lead the way towards agronomic and economic development, improving the sustainability of the region, increasing our energy security, and positively impacting the environment. Simultaneously, crop diversification may also lead towards expanding food and feed market opportunities for the region. A near term goal will be to increase oilseed acreage from <1% to 10% within the next 5-10 years.
After five years of research and outreach, WSU and USDA-ARS scientists and staff have identified specific opportunities, benefits and constraints for oilseed and cellulosic production in each of the each of the four major cropping zones defined by precipitation and temperature. New discoveries and information shared from fifteen projects across the state of Washington is helping fuel more interest from growers about the opportunities for improved overall production when including an oilseed or cellulosic crop in their rotation. A summary of future plans for 2012 can be found on page 87. Highlights of the most recent findings to date include:
Regions 1 and 2: High, Intermediate and Low Rainfall Zones of Eastern Washington
- Spring canola as a viable alternative crop in rotation with winter wheat. Yield results from spring canola in three-year crop rotations at WSU Cook Agronomy Farm from 2001-2009 averaged 1900 lb/acre. Yield of broadcast spring canola was similar to no-till, indicating the potential of early spring seeding into winter wheat residue. Economic analyses show that while spring canola had negative net returns, other rotational crops were also unprofitable. Given current market prices for canola, the economic analyses would change dramatically, as it is at more than double the average price of $12.80/cwt during the study period. In north central WA, the first year of spring canola production was successful with yields averaging over 1000 lb/acre at 7- or 14-inch row spacing.
- Rotational benefits for wheat production. Numerous producers in eastern WA have observed increased wheat yield following an oilseed crop in rotation. Data from a study with eight different spring crops grown before winter wheat indicated that winter wheat following spring wheat and barley performed poorer than following broadleaf crops. These data suggest that growers may be able to assign rotational benefits to oilseed crops due to increased productivity of winter wheat and reduced nitrogen (N) fertilizer costs to obtain those yields. Use of herbicide resistant canola provides greater weed control throughout the entire rotation. Another study found that spring wheat after winter canola produced a significantly higher yield than after winter wheat despite the fact that there were no differences in soil water content after harvest of winter canola and winter wheat. These data show that winter canola provided a significant rotation benefit to spring wheat compared to winter wheat that was not related to water.
- Overcoming herbicide carryover. In the high rainfall, annual cropping zone, Group 2 residual herbicides continue to pose a major constraint to producing oilseed crops, particularly canola and camelina. One mutant population has been identified in camelina that shows resistance to all Group 2 herbicides tested, and in 2011 seed was sent to two commercial breeding programs. Incorporating the mutation into several widely grown cultivars may provide a valuable tool for reducing risks associated with camelina production and increasing adoption of camelina as a rotation crop in this and other regions.
- Three-for-one forage + oil + meal crop. It is well recognized that winter canola can be grown as a biennial crop (one planting, two seasons). A biennial canola study on 17 acres near Pullman examining interseeded winter canola and spring peas as a potential source of forage showed positive results. Plants swathed and ensiled late summer 2010 had good dairy cow feeding qualities and substituted well for alfalfa or corn silage into a total mixed ration for lactating dairy cows without affecting milk production or composition. Nitrate-N concentration was reduced 80% by ensilage. Canola regrowth following swathing exhibited good winter survival, and canola harvested in 2011 yielded 2200 lbs/acre. This experiment also demonstrated it is feasible to plant winter canola as early as July 1 and successfully achieve high over-winter survival and grain yield in the subsequent year.
- Refining fertilizer recommendations. The four year N x sulfur (S) fertility experiment indicates that accurate estimation of soil N supply and canola yield potential is critical in determining proper N fertilization rates. This research suggests N fertilizer rates can be reduced if residual N is high, because canola can aggressively utilize soil N carried over from previous seasons. Variation in oil concentration with N and S management appears to be minor, but variation amongst site years could be related to fall vs. spring canola. There appears to be a physiological link between chloride (Cl) nutrition and cold tolerance in canola, related to the freezing point depression of cell sap. This information suggests 1) further Cl soil fertility research on canola is needed to determine if cold tolerance can be enhanced with Cl fertility and 2) existing regional guidelines for canola fertility management need modified with the goal of maximizing cold tolerance, and yield and oil productivity.
- Increasing canola adoption. In north central Washington, there was no yield advantage in 2011 to increasing the seeding rate, or planting in early or late August. Thus, the recommended time of planting is during August when cool weather is forecast. Winter canola acreage has increased in Lincoln and Douglas Counties from 15 acres in 2007 to 2500 acres planted in 2011 as a result of concerted efforts by USDA-ARS and WSU research and extension, and in connection with the Colville Confederated Tribes.
- Successful camelina establishment. Camelina can be successfully sown over a wide range of planting dates ranging from early fall to early spring. Fall-planted camelina has excellent winter hardiness, similar to that of winter wheat. However, due primarily to lack of in-crop herbicides to control winter-annual broadleaf weeds, we recommend that growers apply glyphosate or other non soil residual burn-down herbicide in mid-to-late February to control weeds, followed by late February-early March camelina planting.
- Increasing camelina seeding efficiency. Both direct drilling and broadcasting were successful methods for camelina stand establishment. From an economic standpoint, we recommend that growers use the broadcast planting method as broadcast applicators more than 60-ft wide are readily available to rent from local chemical dealers that easily allow planting of 400 acres per day. Conversely, grain drills are not as wide, more expensive to rent or own, generally need to operated at a slower speed, and thus can cover only a fraction of the acres of broadcast machines during a given time period.
- Managing camelina residue in rotation. Growers need to be mindful that camelina produces relatively little residue. With heavy tillage, soil erosion may be a problem during or after camelina production. To reduce the potential for soil erosion, we recommend that (i) camelina be planted directly into the standing and undisturbed stubble of the previous crop (i.e., no tillage), and (ii) limited or no tillage be conducted after camelina seed harvest and before planting the subsequent crop. This is especially important if a long fallow cycle is scheduled in the rotation after camelina seed harvest.
- Increase seed size to increase yield potential. Establishment of camelina and canola can be difficult in both deep-furrow planting and direct seed systems due primarily to the small seed size. Research has identified a unique mutation of plant-specific genes that result in increased seed size in camelina and a 30% increase in hypocotyl length, resulting in taller seedlings with no negative impact on adult plant size. With larger seed size and taller seedlings, stand establishment can be improved, and seed loss from combine reduced, resulting in increased yield potential.
- Identifying pathogens: Twenty canola cultivars tested in 2011 for resistance to Rhizoctonia were killed when exposed to AG2-1 (Rhizoctonia solani). One cultivar showed tolerance to damping-off from R. solani AG 8, AG 10 and the binucleate Rhizoctonia, while two genotypes exhibited high level of tolerance to R. solani AG 10. Camelina plants infected with downy mildew resulted from infested seed, indicating that the disease is seed transmitted. Primers were developed that could detect the pathogen, which will be useful in seed certification and testing. However, the primers may also cross-react with H. parasitica, downy mildew of Brassicas. We are also not sure of the relationship between downy mildew on camelina and canola – can they cross infect? Greenbridge control appears to be the best strategy in minimizing damage from pathogens in canola, and producers should use certified or tested seed to reduce the chance of downy mildew in camelina. Seed treatment with mefanoxam may control the disease.
- Dryland safflower in rotation. Safflower was successfully established for the second time in a large scale, on-farm dryland cropping systems experiment near Ritzville. The 2011 crop yielded 1090 lbs/acre, and rotation benefits compared to other three-year crop rotation treatments will be available after the 2012 crop year.
Region 3: Irrigated Central Washington
- Safflower shows promise. Irrigated safflower yields averaged 2770 lb/acre, and yields were significantly higher with 100 lb N/acre than 145 lb N/acre. Yields averaged over the four years of the study were not significantly different between 90 and 70% ET, suggesting a potential 4.7-7.5” water savings using a deficit irrigation strategy. Similarly, oil yield was higher under deficit irrigation, a reflection of higher yields and greater water use efficiency.
- Cellulosic forage. Irrigated switchgrass production at Prosser has shown that warm season grass hay can be consistently produced in the northern Columbia Basin region. A critical factor to consider once production increases is how to store the feedstock bales pending processing at a biorefinery. Our studies will provide four years of storage data that can be used in developing guidelines for long term storage.
Region 4: Western Washington
- Spring oilseed trials at Mount Vernon revealed no clear yield trends across seeding or fertilizer rate, although all mustard plots yielded three to four times as much seed as camelina. Research at Puyallup focused on the use of biosolids for organic fertilizer on certified organic land. Winter canola yields increased with higher biosolids application rates, but not significantly. Average yield across fertilizer rates was 2355 lbs/acre, considerably less than expected due to pre-harvest shattering. In general, low N fertilizer resulted in higher weed populations by April, likely because the canola crop was less vigorous. Fall seeded camelina winterkilled; however spring camelina was successfully established and yielded over 3000 lbs/acre in 2011. Spring seeded canola, rapeseed, mustard, and camelina yields did not significantly differ by fertilizer regime.
- Supplying oilseed analyses. Almost 2000 oilseed samples have been submitted for analysis by WSU researchers since 2008. The most recent set of samples (825 total) were from camelina trials at several locations in the PNW. Correlating crop yield and oil analyses by agroclimatic zones, varieties, fertilizer rates, and other factors will allow more site-specific crop recommendations for maximum potential seed and oil production.
- Reaching larger audiences. Outreach and extension efforts expanded again in 2011, with attendance exceeding 1845 at 25 events, including the following:
- oilseed research plots and/or presentations featured at nine field days
- 250 attendees at inaugural Oilseed Crop Production Workshops at three locations with positive feedback to continue in 2012
- poster and oral presentations by WSU and USDA-ARS personnel at five regional and national conferences
- experienced oilseed growers and university researchers speaking at several local farmer breakfast and luncheon meetings
- WSU and USDA-ARS attending quarterly Washington Canola and Rapeseed Commission meetings in person or by phone, serving as liaison between the university and the commission, and keeping the Commission abreast of current oilseed research.
- Increasing online interest. There were almost 2000 hits on the Biofuels website in 2011, two-thirds of which came from 47 cities in Washington.
- Continuing collaboration. Multi-agency collaboration continued with the Confederated Colville Tribes, with USDA-ARS and WSU most recently receiving a small grant from the CCT to expand oilseed production into other tribal districts and to advise them on planting canola.
- Providing educational materials. The first set of case studies about oilseed producers in the four production regions of Washington was published as an Extension manual and the remaining three sets are being edited for publication in 2012. These grower case studies highlight grower insights, advice to other growers, and perceived benefits and constraints in producing canola in wheat rotations. The WBCS research team published a fact sheet about canola growth, development and fertility, and several refereed journal articles and Extension fact sheets and bulletins about canola, camelina, and switchgrass production in the PNW are pending publication in 2012.
- Fostering related research. Oilseed rotation and fertility experiments are being co-supported by the USDA-NIFA funded REACCH (Regional Approaches to Climate Change) project, with recognition of EPA Life Cycle Assessment that substitution of biodiesel for petroleum diesel will reduce greenhouse gas emissions by 50%.