Sustainable Cropping Systems for Dual-Purpose Biennial Canola

Sustainable Cropping Systems for Dual-Purpose Biennial Canola

Summary

This project is aimed at evaluating, in the Northwestern United States region, the agro-environmental potential of intensive sustainable farming practices which are based on pea-canola/mustard double cropping systems and  include dual-purpose canola and three to four harvestable crops in two seasons under irrigation and rain-fed environments. Four studies have been commenced in two states, Montana and Washington. In Washington, two studies were established in the spring of 2015 on irrigated land in Prosser at the Irrigated Ag Res & Extension Center (IAREC) and near Sunnyside on a land provided by Mr. Ted Durfey. In Montana, two studies were established in Havre, one at Northern Ag Res Center (NARC) under supplemental irrigation, and the other on a dryland provided by Mr. Jeff Hockett, about four miles away from NARC. In Idaho, the project was initiated the fall of 2015. However, due to planting restrictions imposed on the majority of southern and central Idaho for canola due to concerns of cross-pollination with mustard seed (a widely grown high-value crop in the area), the decision has been made to switch from canola to mustard. Field implementation of the project in the state of Oregon is scheduled to start in the spring 2016.

The general experimental design in all four states is a split-split plot design with four replications. The main plots are cropping systems (fallow and peas), sub plots are canola/mustard purpose type (dual or single), and sub-sub plots are seven fertility treatments. The dual-purpose biennial winter canola/mustard treatment would be hayed for feed or grazed directly in late summer or early fall; it will then be allowed to regrow and harvested for seed the following year. The single-purpose canola/mustard would be grown only for seed. Green peas would be planted early spring and harvested for fresh pod yield in early summer. Then, they would be terminated chemically (Roundup) or mechanically (disked in), depending on the prevailing tillage practice of the region of interest. Canola/mustard would be planted in early fall at all locations and then harvested the following summer. Where possible, a forage crop will be seeded thereafter, as catch crop, and harvested before the seeding of winter wheat, which would complete the intensive farming cycle of approximately 27 months. Despite a few accidental setbacks in Montana and Washington, preliminary results show that the overall project is up for a good start in the two states.

In Montana, in this first cycle, fresh pea pod yield was 8157 and 2205 lb/Ac at NARC and Hockett’s field, respectively. At the NARC site, average canola forage was 635 lb/Ac and forage yield differed between cropping systems (fallow versus pea) and among fertilizer treatments (Figure 1) where the manure and compost combo resulted in the highest forage yield (Figure 2). In the dryland conditions (Hockett’s field), canola plants grew understandably at a lower rate, and a roaming herd of cows indiscriminately grazed the entire field hindering data collection.

In Washington, at the Prosser location, the biomass and pod dry matter yields of pea were 4336 and 2524 lbs/Ac, respectively in 2015. No pod yield was measured at Sunnyside due to flower abortion from herbicide application in early June to control an outbreak of weeds.

• Figure 2. Plant density and hay yield (ton/Ac)at NARC site, Havres, MT
• Figure 1. General field-layout and treatment structure of the experiment on sustainable cropping systems for dual-purpose biennial canola. Cell upper numbers denote the treatment numbers displayed in the legend, whereas cell lower numbers denote plot numbers.

Objectives/Performance Targets

Quantify the fertilizer nitrogen requirements of biennial canola/mustard under the double-cropping scenarios using organic and inorganic fertilizer sources. Output: Determined N requirement of double-cropped dual-purpose biennial canola/mustard cropping systems.

Quantify the nitrogen contribution of green pea to the succeeding dual-purpose biennial canola/mustard and winter wheat. Output: Estimated nitrogen contribution of green pea to succeeding biennial canola/mustard and winter wheat.

Assess the forage, silage, and hay quality of the canola grown after a fallow or a green pea crop. Output: Quantified feed quality, oil yield and quality of dual-purpose biennial canola under double-crop systems.

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.

Compare the winter survival of canola under single and dual-purpose systems. This objective addresses the question of whether cutting canola in the fall affects winter survival and thus the final oil yield of the dual-purpose crop. Output: Assessed winter damage/survival of dual-purpose and single-purpose canola.

Assess the overall 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

Conduct outreach on the studied cropping systems to increase the awareness of growers and the agricultural industry. Output: organized field days, workshops, and one-to-one meetings with target groups. Hardcopy publications, online, multimedia, and other outreach productions.

We plan to run the project for at least three cropping cycles; two of which would focus on performing detailed studies on double-cropping canola/mustard with fresh pea. The project cycle which includes double-cropping requires approximately 27 months. In the first year, fresh pea will be planted in the spring and harvested in early summer. Following this precursor crop, dual-purpose biennial canola or mustard will be planted and harvested for forage in early fall and for oil in the summer of the second year. Following the harvest of canola, a forage crop will be planted, where applicable, as a catch crop that will precede winter wheat seeded in the fall.

Accomplishments/Milestones

Of the six studies planned for 2015/2016 cropping cycle, four were established in the states of Washington and Montana, one was initiated in Idaho in the fall of 2015, and the last one is scheduled to start in the spring of 2016.

MONTANA

Fresh pea cultivar Prevail was successfully planted and maintained at 200 lb/Ac seeding rate on April 10, 2015 using Conserva Pak seed drill.

Fresh pea cultivar Prevail was harvested on June 26, 2015 for both biomass and fresh grain yields at both sites. Fresh pea pod yield was 8157 and 2205 lb/Ac at NARC and Hockett’s field, respectively.

The seven organic and inorganic fertilizer treatments were applied onto the 112 plots of each experimental fields at the NARC station and Hockett fields (Figure 1).

A wheel-move sprinkler irrigation system was installed and set up at the NARC field in July 2015 (Figure 3).

A Roundup Ready® canola hybrid, HyCLASS®, was planted on July 31, 2015 at the irrigated site in Havres, and on August 5, 2015 in the dryland site using a Conserva Pak seed drill at a seeding rate of 8.0 lb pure live seed.

Following 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 (Figure 4).

The subplots intended for forage were sampled at the height of 3-4 inches and at the rosette (26 -27 on BBCH scale) stage at the Havre site on September 11, 2015 to determine canola forage yields and quality (Total N content, crude protein, acid detergent fiber (ADF), and total digestible nutrients (TDN). The samples were sent to Washington State University, attention Drs. Steven Fransen and Donald Llewllyn, co-PIs of this project. At the NARC site, average canola forage was 635 lb/Ac and forage yield differed between cropping systems (fallow versus pea) and among fertilizer treatments (Figure 1) where the manure and compost combo resulted in the highest forage yield (Figure 2).

Canola plants were also sampled separately from micro-plots for the determination of forage N15 content. The samples were sent to UC Davis Laboratory.

Twenty bulls were allowed to graze the dual-purpose canola plots on September 14, 2015 (Figures 5; 6).

Plant densities were estimated in grazed-subplots (Figure 7) at the onset of winter. Comparison with spring densities will help determine the effect of grazing on canola winter survival.

WASHINGTON

SOIL SAMPLING: Using a Kaufman soil probe, four soil samples per replication were collected, composted, and subsampled for complete nutrient analysis at 1, 2, 3, and 4 foot depths at both Prosser (H-21) and Sunnyside (Ted Durfey, Natural Selections Farm) for a total of 16 samples per location on April 9 and April 14, respectively. An expanded set of soil samples were collected on July 16 at Prosser and July 23 at Sunnyside, whereby samples were collected from fallow (previous wheat crop) to canola and pea to canola for a total of 32 samples per location. This set of soil samples were collected prior to application of compost (Trt 3), manure (Trt 2) and combination of compost and manure (Trt 7).

APPLICATION OF ORGANIC AND INORGANIC FERTILIZERS: manure, compost, and the combination of compost and manure were applied at Prosser on July 16, 17, 21, and 22. Organic treatments were applied at Sunnyside on July 24, 27, 28, and 29 (Figure 8). After organic treatments were applied they were incorporated by disking into the soil, then irrigated twice weekly until planting winter canola. Inorganic nutrients were applied and incorporated the day prior to planting winter canola at each location.

PLANTING: Pure Line Seeds, Inc. pea line 509 (aka, Prevail), a pea variety intended for fresh market processing, were inoculated with rhizobium bacteria prior to planting. Peas were planted at approximately 140 pounds per acre at each research location on April 10 and April 15 at Prosser and Sunnyside, respectively. A Roundup Ready winter canola hybrid was planted on August 12 and August 21 using a Brillion drill and HI grain drill at 8 pounds per acre at Prosser and Sunnyside, respectively (Figure 9). Sprinkler irrigation systems were installed at both locations (Figure 10). 

FIELD MAINTAINANCE: Weeds were a major problem at both locations. We used Roundup several times the fall before pea planting to control weeds. This was done prior to pea planting. During pea growth a combination of MCPA and Basagran without oil was applied to the Sunnyside peas as a rescue or salvage weed control treatment for weeds that exploded over Memorial Day weekend. This combination did an excellent job controlling weeds but peas were in flowering stage and the herbicides caused total flower abortion at Sunnyside pea plots. At both locations, about three weeks after planting winter canola, we sprayed with Roundup to control germinating weed seedling.

HARVESTING: Field peas were harvested for whole plant and pod yield on June 18 and June 29 at Prosser and Sunnyside, respectively. At the Prosser location, the biomass and pod dry matter yields of pea were 4336 and 2524 lbs/Ac, respectively in 2015. No pod yield was measured at Sunnyside due to flower abortion from herbicide application in early June to control weeds. Winter canola was sampled (Figure 11) and harvested (Figure 12) on October 14 and 23 at Prosser and Sunnyside, respectively. Livestock grazing was simulated by manually clipping canola leave (Figure 13). Leaf samples have been oven dried and in the process of grinding for NIRS analysis. Presently our NIRS is being repaired at FOSS in Minnesota. We are unsure how long it will require for repairs to be made. Regardless, once the NIRS is returned those samples will be scanned and quality predicted.

GREENHOUSE WORK: Pureline Seed Inc., cultivar 509 seed without inoculation of rhizobium were planted in approximately 30 gallon-size greenhouse pots filled with sand and irrigated by drip line. A modified complete nutrient solution with N applied as a mist solution of N¹⁵ was supplied two to three times per week. Pea plants were grown for six to eight weeks and harvested at flowering; oven-dried at 140⁰ F until dry; ground through a 4 mm Wiley Mill then through a 2 mm screen; and stored in Ziplock baggies. Using a splitter each harvest was divided equally for Montana (Roger Ondoua / Kefy Desta) microplots and Prosser microplots. To date, greenhouse pea plants have been harvested on February 9^th, April 2^nd, May 13^th, June 24^th, July 30^th and September 3^rd, 2015. We noticed some greenhouse pots were excessively wet in early September. We decided to allow the pots to thoroughly dry to prevent plant diseases. Pots were replanted in December and the irrigation system modified to reduce water output, producing future healthy N¹⁵ pea crops. New crops of greenhouse N¹⁵ pea crops will be grown throughout 2016.

IDAHO

In 2014-15, it came to the PIs attention that planting restrictions are imposed on the majority of southern and central Idaho for canola due to concerns of cross-pollination with mustard seed – a widely grown high-value crop in the area. Efforts have been made to locate potential collaborators in northern Idaho in order to conduct the study in areas with no restrictions. The PIs from Montana, Washington, and Idaho participated in a planning meeting in Prosser, WA, September 8, 2015. After several months being in contact with commodity groups and oil seed growers, no suitable collaborator/location has been found. The decision has been made to switch from canola to mustard and to initiate the project in the fall of 2015.

The winter wheat (variety Stephens) was planted on November 2, 2015, using 140 lb/a seeding rate. No fertilizer was applied at seeding; this will ensure soil N depletion and easy determination of N made available from pea treatments to mustard crop. The crop will be sprinkle-irrigated starting green-up in the spring.

PIs MEETING

The PIs of this project met in Prosser, Washington, on September 8, 2015 to confer, exchange ideas, and share experience (Figure 14). A second meeting is scheduled on February 15, 2015 in Prosser, Washington. The main goal of this second meeting is to resolve technical issues related to the application of lysimetry, and the proposal by the new project director of an agro-analytical method to estimate N contribution by pea.

• Figure 3. A wheelmove irrigation line operating at the Northern Agricultural Research Center, in Havres, Montana (July, 2015)
• Figure 4. Micro-plots for N recovery analysis at the Northern Agricultural Research Center, in Havres, Montana (July, 2015)
• Figure 5. Overview of single-purpose and dual-purpose plots at the Northern Agricultural Research Center, in Havres, Montana (July, 2015). In the background, cows are grazing a dual-purpose plot.
• Figure 6. A close-up of cows grazing a canola dual-purpose plot at the Northern Agricultural Research Center, in Havres, Montana (July, 2015).
• Figure 10. Sprinkler-irrigated canola field in Prosser, Washington.
• Figure 11. Sampled-canola in a dual-purpose plot
• Figure 12. Harvesting of forage canola in a dual-purpose plot at Sunnyside, Washington
• Figure 14. Project investigators examine a micro-plot at the Prosser Field on september 8, 2015.
• Figure 9. Seeding of Canola in August 2015 at the Prosser Field, Washington.
• Figure 8. Compost Application at Sunnyside on July 24, 2015, Washington
• Figure 7. Close-up of Canola single-purpose and dual-purpose plots
• Figure 13. Manually-clipped canola forage at Prosser, Washington

Impacts and Contributions/Outcomes

At this stage of the project (one third of the project cycle), no impacts and contributions to report yet. 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.

Collaborators: