Sustainable Cropping Systems for Dual-Purpose Biennial Canola

Sustainable Cropping Systems for Dual-Purpose Biennial Canola

Summary

In the Northwestern United States (NWUS), canola (Brassica napus L.) has not been integrated into the existing cropping systems despite the many ecological services and economic benefits it might provide. Given the multi-purpose nature of canola, it is appropriate and timely to introduce a dynamic and viable dual-purpose canola cropping system in the region. The first year’s experiments are underway to evaluate the productivity and agroecosystem benefits of a pea-canola double-crop cropping system in NWUS region. Of the six studies planned for 2015/2016 cropping cycle, four were established in Washington and Montana. The Washington studies were established on irrigated land in Prosser at the Irrigated Ag Research & Extension Center (IAREC) and near Sunnyside on land provided by Mr. Ted Durfey. In Montana, both studies were established in Havre, one at Northern Ag Research Center (NARC) under supplemental irrigation, and the other on a dryland provided by Mr. Jeff Hockett, about four miles away from NARC. Experiments were arranged in a split-split plot design with four replications. Main plots are cropping systems (fallow and peas), sub plots are canola purposes (dual or single), and sub-sub plots are seven fertility treatments (see Appendix 1). The dual-purpose canola treatment would be hayed for feed or grazed directly in late summer or early fall, allowed to regrow, and harvested for seed the following year. The single-purpose canola would be grown only for seed. Peas would be planted in April and harvested for fresh pea pod yield in June. Then, they would be terminated with roundup and canola would be planted in August at all locations. In this first cycle, fresh pea pod yield was 3.7 and 1.0 ton/Ac at NARC and Hockett’s field, respectively. At the NARC site, average canola forage was 1.4 ton/Ac and forage yield differed between cropping systems (fallow versus pea) and among fertility treatments (inorganic fertilizers and organic amendments) where the manure and compost combo resulted in the highest forage yield (1.7 ton/Ac). Preliminary results suggest that the total productivity of a land can be improved by some of the proposed system treatments while improving ecosystem service of an arable land. The fresh pea pod yield data are not yet processed from Washington. The Idaho study will be replaced with brassica due to restrictions on canola. Oregon will begin the study by planting pea in spring 2016.

Objectives/Performance Targets

Objectives and expected outputs

1. Quantify the fertilizer (N) requirements of biennial canola under double-cropped scenarios and using organic amendments as fertilizer sources

Output: Determined N requirement of double-cropped dual-purpose biennial canola cropping system

2. Quantify the N contribution from pea to succeeding dual-purpose biennial canola and winter wheat

Output: Estimated the N contribution of legume precursors crops such as green pea to succeeding biennial canola and winter wheat

3. Assess forage, silage, and hay quality of canola grown in mix and following green pea

Output: Quantified feed quality oil yield and quality of dual-purpose biennial canola under double-crop systems

4. Assess oil quality of biennial canola double-cropped with peas

Output: Compared oil yield and quality of dual-purpose and sole purpose biennial canola following pea and fallow

5. Compare the winter survival of canola under sole and dual-purpose systems. This objective addresses if cutting canola in fall affects winter survival and thus final oil yield as a dual-purpose crop

Output: Assessed winter damage/survival of dual-purpose and sole-purpose canola

6. Assess the total productivity and estimate the overall profitability of double-cropped dual-purpose biennial canola

Output: Determined system level cost-benefit of dual-purpose and sole-purpose biennial canola under double-crop system

7. Conduct outreach on the cropping systems for increasing awareness of growers and industry

Output: Conducted several field days, workshops, and one-to-one meetings with target groups. Developed publications, online, multimedia, and other outreach products

We planned to perform the project for three cropping cycles. Two of the three cropping cycles would focus on performing detailed studies on double-cropping canola with fresh pea. A cropping cycle for a double-crop requires a total of 18 to 20 months (or more). In the first year, fresh pea would be planted in spring and harvested in early summer. Following the precursor crop, we would plant dual-purpose biennial canola, which would be harvested for forage in early fall and for oil in the summer of the second year. Following the harvest of canola, plots would be planted to winter in fall. The design of the experiment includes three factors that have been/will be implemented on 0.5 to 1 acre in the first two cycles of the study and 5 to 50 acres in the third cycle (includes only adaptable practices). The experimental design is a split-split plot with four replications. Main plots are cropping systems (fallow and peas), sub plots are canola purposes (dual or single), and sub-sub plots are seven fertility treatments (Appendix 1). The dual-purpose canola treatment would be hayed for feed or grazed directly in late summer or fall, allowed to regrow, and harvested for seed the following year. The single-purpose canola would be grown only for seed.

Of the six studies planned for 2015/2016 cropping cycle, four were established in Washington and Montana. The Washington studies were established on irrigated land in Prosser at the IAREC and near Sunnyside in Ted Durfey’s farm. In Montana, both studies were established in Havre, one at NARC under supplemental irrigation, and the other in a farmer field about four miles away from the center on a dryland.

In Montana, fresh pea cultivar Prevail was planted at 200 lb/Ac seeding rate on April 10, 2015 using Conserva Pak seed drill, and harvested on June 26, 2015 for biomass and fresh pea seed yield from an area of 10 ft² at both sites. HyCLASS® 125W, a Genuity® Roundup Ready® HyCLASS® canola hybrid was planted on 7/31/2915 at the Havre irrigation supplemented site and on 08/05/2015 in the dryland site at Havre using a Conserva Pak seed drill at a seeding rate of 8.0 lb pure live seed following pea residue termination. After canola planting, N¹⁵ enriched pea residue and N¹⁵ labeled urea were applied to 2 ft x 2 ft micro-plots in selected treatments to address the nitrogen recovery objective. The strips intended for forage were clipped at a height of 3-4 inches at the rosette (26 -27 on BBCH scale) stage from an area of 10 ft² at the Havre irrigation supplemented site on September 11, 2015. Plants were also clipped separately from microplots for determining canola forage N¹⁵ content. After clipping, 20 bulls were left in the dual-purpose plots to graze on September 14, 2015. From the clipped samples, both fresh and dried biomass/forage yields were estimated for each sub-sub plot. Wet weight of forage was recorded on-site, and subsamples were withdrawn for determining moisture content and feed quality. Total canola forage N content, crude protein, acid detergent fiber (ADF), and total digestible nutrients (TDN) will be determined with NIRS™ 5000/6500 Feed and Forage Analyzer (Eden Prairie, MN). No forage harvesting yet from Mr. Hockett’s field as the crop is still catching up following good rain in early September. It is unlikely to get a harvestable biomass before winter freeze at this site. In spring 2016, more measurements will be collected as per the project protocols. The canola from this cycle will be harvested for seed in July 2016. Following Canola, winter wheat will be planted to the entire experimental area to assess the carryover effect of the double crop system and fertility treatments. Yield of winter wheat will be collected in June or July 2017.

In Washington, fresh pea cultivar Prevail was planted at 140 lb/Ac seeding rate on April 10 and 15, 2015 at Prosser and Sunnyside, respectively using Brillion drill. Peas were harvested on June 18 and 29 2015, at Prosser and Sunnyside, respectively, for biomass and fresh pea pod yield from the entire plot. At Sunnyside, no pod yield was obtained due to flower abortion attributed to herbicide injury. HyCLASS® 125W, a Genuity® Roundup Ready® HyCLASS® canola hybrid was planted on 8/12/2015 at Prosser using Brillion drill, and on 08/21/2015 at Sunnyside using a HI grain drill at 8.0 lb/Ac pure live seed following pea residue termination with roundup. The strips intended for forage are not yet clipped at both sites in Washington. Following forage harvesting, canola will regrow before winter-induced growth termination. In spring 2016, more measurements will be collected as per the project protocols. The canola from this cycle will be harvested for seed in late June 2016. Following Canola, winter wheat will be planted to the entire experimental area to assess the carryover effect of the double crop system and fertility treatments. Yield of winter wheat will be collected in June 2017. The second cycle of the project will begin in spring 2016 by planting peas in a field planted to wheat in 20215, adjacent to the canola from the current cycle.

Accomplishments/Milestones

In Montana, average fresh pea pod yield was ?3.7 ton/Ac (±0.67 ton/Ac) at Havre irrigation supplemented site. At this site, average canola plant population was 7.6 and 6.7 plants/ft² for fallow and pea plots, respectively. Likewise, at the irrigation supplemented site in Havre, seventeen-percent moisture adjusted canola dry matter yield cut at rosette growth stage 26-27 was 1.4 ton/A. Fertility treatments significantly affected canola forage yield. The manure and compost combo had the highest forage yield, and the difference was significant when compared with the check (Appendix 2). Mr. Hockett’s field produced 1.04 ton/Ac ((±0.35 ton/Ac) fresh pea pod yield. At this site, the canola is not yet ready for harvest.

In Prosser WA, pod yield data have been collected but not processed yet; pod yield is not available for the Sunnyside site due to herbicide damage.

Impacts and Contributions/Outcomes

No impacts and contributions to report at this time. However, following a series of conversations at different meetings in winter 2014-15 regarding this Western SARE funded project, D. Roddy in Fort Benton, MT ended up planting 60 acres to a HyCLASS® 115W for hay/grazing and seed. The project collaborator T. Durfey is planning to put some acres under dual-purpose canola in 2016.

Publications

1. Girma, Kefyalew, Steven C. Fransen, and Harold P. Collins. 2015. Yield and nitrogen recovery of biennial canola forage following peas in the Northwest US. ASA, CSSA & SSSA International Annual Meetings, Nov. 15-18, 2015, Minneapolis, MN.
2. Girma, Kefyalew, Steven C. Fransen, and Harold P. Collins. 2015. Forage and seed yields, and forage qualities of biennial canola following peas in the Pacific Northwest. Western Society of Crop Science, June 16-17, 2015, Logan, UT. 91835

• Experimental plots, Havre, MT
• Bulls testing canola, Havre MT.
• Bulls crossing the line for more canola.
• Partially grazed and ungrazed plots, Havre, MT.
• Canola plant count and hay yield at Havre, MT
• Bulls grazed canola to the desired height.
• Recycling in action.

Collaborators: