Final report for WRGR19-02
Cover crops are an important tool in many production situations. They can be effective for weed suppression, preventing nutrient leaching and soil erosion, increasing soil organic matter, improving soil tilth, and fixing atmospheric nitrogen. Previously funded SARE projects SW14-013, SW11-122, SW11-072, and SW07-014 have shown the importance of cover crop selection for achieving particular goals and also how planting date, planting rate, termination date, and termination strategy can affect weed and nutrient dynamics. Similar efforts by NRCS have also contributed knowledge and tools for effective cover crop use (i.e. a cover crop decision tool). Through this proposal, our team will use previously funded WSARE cover crop research to implement on-farm demonstrations and use the Western Cover Crop Council (WCCC) as the venue to share this information with Western regional farmers. Specifically, we will:
- Support on-farm cover crop demonstrations in Washington, Oregon, and Idaho to highlight success from previous SARE cover crop projects. Demonstrations will show how variety, planting rate, planting date, and fertility practices affect specific management goals.
- Develop simple and systematic cover crop evaluation criteria for farmers. Evaluation criteria will assist in information sharing and be applied to on-farm demonstrations to effectively collate results. Results and the criteria will be shared on the WCCC website.
- Introduce producers to the recently developed NRCS Pacific Northwest Cover Crop Selection Tool, a Microsoft Access Database, and provide feedback on improving the tool content and accessibility.
- Share project results through regional conferences and field days.
Objective 1. Support on-farm cover crop demonstrations in Washington, Oregon, and Idaho to highlight success from previous SARE cover crop projects. Demonstrations will show how variety, planting rate, planting date, and fertility practices affect specific management goals. Named varieties will be used when possible. Demonstrations: 3 summer (Year 1), 6 winter and 3 summer (Year 2), and 3 winter (Year 3).
Objective 2. Develop simple and systematic cover crop evaluation criteria for farmers. A consistent criteria for cover crop evaluation will facilitate knowledge sharing across regions and provide robust information for a selection tool. We will develop an evaluation system that will guide cover crop evaluation and research for unreplicated demonstrations such as those proposed for this project to more involved trials (Year 1).
Objective 3. Introduce producers to the recently developed NRCS Pacific Northwest Cover Crop Selection Tool, which is currently a Microsoft Access Database, and provide feedback on improving the tool content and accessibility. Host a WCCC training webinar featuring Annie Young-Mathews (co-creator of the database10) in January 2020 (Year 1) for agriculture professionals. Work one-on-one or in small groups with growers to use the tool in an effort to design the on-farm demonstrations for this proposal (Years 1 and 2) then collate feedback on the tool and include recommendations for improving the content and accessibility (Year 3).
Objective 4. Share project results through regional conferences and field days. At least one outreach event will occur at demonstration farms in each cooperating state WA, OR, and ID during each year of the project (Years 1, 2, and 3). In addition, the project, decision tool, and results will be featured at state meetings in WA, OR, and ID (Years 2 and 3).
Cover crops provide a wide range of ecosystem services, including nutrient retention, weed suppression, and carbon storage. Usually cover crops do not negatively impact cash crop yield, but they can increase risk1. Risks are associated with poor establishment, poor termination and insufficient incorporation of cover crops.7,8 Producers frequently question how to utilize cover crops. For example, in focus groups in western WA in 2017, producers expressed interest in integrating cover crops into crop rotations and animal-integrated systems.9 Barriers identified in the focus groups were similar to those found by Dunn et al.11 in a national survey: cover crops make planting more difficult, termination is difficult, they reduce cash crop yields, and are costly. Understanding these risks and how to mitigate trade-offs can increase the likelihood that producers continue the practice11. By demonstrating cover cropping best practices for specific goals, as shown in recently completed SARE projects (SW14-013, SW11-122, SW11-072, and SW07-014), we will assist producers in reducing risks while maximizing ecosystem services and the positive economic impacts of cover crops. Though we identified and screened 139 SARE funded projects that mentioned “cover crops” from 2000 through 2016, few of the projects included variety or species trials. These four projects specifically addressed the importance of cover crop selection for achieving particular goals and also how planting date, planting rate, termination date, and termination strategy can affect weed and nutrient dynamics.
Through previous SARE funded projects PIs Collins and Golden examined cover crop varieties for specific management goals and demonstrated that winter cover crop variety selection is critical to planning for spring. Collins12,13 focused on cover crop-based organic reduced tillage systems in the Mediterranean climate typical of western Washington and Oregon. Researchers evaluated cover crops for growth stage timing and organic no-till termination. Cover crop termination without tillage was successful at flowering and thus early maturing varieties were preferred. ‘Aroostook’ rye flowered 3 weeks before common rye and common vetch matured 4 weeks earlier than ‘Purple Bounty’ (hairy vetch). For tilled systems, growers may benefit from a slower maturing variety. Golden14 evaluated twelve cover crop species in high-desert systems in Idaho classified into three groups: nitrogen-fixing, grass/grains, and brassicas. Each group offers specific agronomic benefits (e.g. forage, soil fertility, weed suppression) and can be planted alone to maximize one objective or in a mix to obtain multiple benefits. Drost’s SARE project also examined cover crop varieties in a dry desert environment and found large differences in establishment and success of different crops.15
Cover crop selection and management is critically important for nitrogen availability to the following crop. Golden found legumes contributed 16-75 lbs/acre of plant available nitrogen and canola/triticale mix scavenged 260 lbs/acre of nitrogen after 55 days of fall growth.14 Collins13 found percent nitrogen in vetch decreased slightly from vegetative stage to flowering, but total nitrogen contribution was greatest when termination occurred at late flowering.
This proposal leverages previous work with meaningful demonstrations and accessible evaluation criteria toward a robust decision-tool tailored to specific management goals across diverse climates and cropping systems.
- (Educator and Researcher)
- (Educator and Researcher)
- (Educator and Researcher)
- (Educator and Researcher)
- (Educator and Researcher)
- (Educator and Researcher)
Education & Outreach Initiatives
: Familiarize WCCC members with the Pacific Northwest Cover Crop Selection Tool
June 24, 2019 Annie Young Mathews, Oregon NRCS, presented to Western Cover Crop Council
20 Agriculture professionals attended and learned about the cover crop selection tool that resides in an ACCESS database. This meeting introduced WCCC members around the Pacific Northwest to that cover crop selection tool and has informed conversations throughout the Western U.S. The WCCC is now collaborating with Cover Crop Councils around the U.S. to develop an interactive online Cover Crop Selection tool for the West as part of a new agreement with the USDA Natural Resources Conservation Service. Information in the PNW Cover Crop Selection Tool and results from the on-farm trials from this project will inform performance ratings and other information in the Western Cover Crops Selection Tool.
Share cover crop experiment results
March 2020, hosted by WSU Puyallup (Doug Collins) and Pierce Conservation District with OSU speaker Nick Andrews.
78 Participants. Participants were evaluated through a post-event evaluation instrument. Polls were also used during the event to gage interest in future research directions. Based on the post-event evaluation (n=13), most participants had 2 or less years of experience with cover crops. 73% of attendees greatly increased their knowledge about the economics of cover crops and 82% greatly increased their knowledge about incorporating cover crops in rotation and nutrient cycling with cover crops; 54% greatly increased their knowledge about cover crop selection; 64% greatly increased their knowledge about cover crops and soil health; and 82% planned to make changes in their use of cover crops following the event.
A part of the grant project is to develop protocols for on-farm cover crop evaluation. These protocols are designed to facilitate many different trials and the developmentof a cover crop database.
5 cover crop protocols were developed:
- Workflow Diagram (overview of all protocols)
- Experiment Details Protocol
- Soil Sampling Protocol
- Cover Crop Biomass Separation Protocol
- Stand Evaluation Protocol
- Cover Crop Trial Details & Results
Different tiers or levels of evaluation were developed for cover crop trials with different objectives and levels of resources. The primary level compares basic attributes of cover crops such as stand establishment and final biomass. Examples of more specific objectives include cover crop performance when interseeded into cash crops and nutrient dynamics after incorporation (e.g. nitrogen). The trial database includes degree-day accumulation from seeding to cover crop termination. In the absence of detailed cover crop degree-day models we use a 32°F base temperature and single sine calculation method from nearby weather stations.
Educators and farmers involved participated to develop the protocols. 8 participants.
Work with producers to determine highest value experimental topics with cover crops. Execute experiments on-farms and gather data for cover crop database.
- Summer 2020, WA – Early Bird (Summer cover crops) 4ppl involved in planting. Field day held April 7, 2021. 14 participants
- Summer 2020, WA – Zestful Gardens (Summer cover crops) 4ppl
- Fall 2020, WA – Zestful Gardens (Vetch variety trial) 3ppl
- Fall 2020, WA – Four Elements Farm (Vetch variety trial). 3 ppl
- (R2GR) Summer 2020, OR – 47th Avenue Farm (interseeding) (3 ppl)
- (R2GR) Summer 2020, OR – Koch Legacy Farm (interseeding) (2 ppl)
- (Tualatin) 2020-2021*, OR - Pumpkin Ridge Gardens (winter and interseeded cover crops) (2ppl)
- (Tualatin) 2020-2021*, OR – Gales Meadow Farm (winter and interseeded cover crops) (5 ppl)
- (Tualatin) 2020-2021*, OR – Stoneboat Farm (winter and interseeded cover crops) (3 ppl)
- (Tualatin) 2020-2021*, OR – La Finquita del Buho (winter and interseeded cover crops) (2 ppl)
- (Tualatin) 2020-2021*, OR – Adelante Mujeres (winter and interseeded cover crops) (3ppl)
- (Tualatin) 2020-2021*, OR - Square Peg Farm (winter and interseeded cover crops) (2 ppl)
- Wide-row silage corn with cover crop interseeded (Idaho) (30” check (standard planting) no cover crop, 60” twin row corn with cover crop interseeded at V5, 44” twin row corn with cover crop interseeded at V5; Seeding rate 40,000/acre. Results indicate successful cover crop establishment and growth while maintaining silage yield.. The study will be trialed again in 2022. One local grower wants to try this on his farm but lack of irrigation water in 2020 won’t allow it this year.
- Tour of the silage demo for our Idaho county agents summer meeting on Sept 26th, 2021. There were 15 educators present.
- 20 acre demonstration (Blaine county, ID). Cover crop mix with winter wheat, grazed the forage all summer and this year we will see if the wheat can produce a grain crop. Snow mold from winter 2020-21 killed most of the wheat.
- Tour of the winter wheat/ cc study on July 29th, 2021 with 10 producers attending.
- 2020 Planted cover crop demo at the research farm to look at late season species that can provide winter protection (ID)
- 2021-Planted summer cover crop demo at the research farm to look at forage potential of individual species and another late planted set of mixes to see if forage could be grown after silage harvest. Results of summer plantings yet to be compiled. The late planted mixes provided good winter cover crop but not enough forage for grazing (too late).
- 2021-2022, OR –47thAvenue Farm** (interseeding in late fall and over-wintered vegetables) (3 ppl)
- (Tualatin) 2021-2022*, OR -Pumpkin Ridge Gardens (zero immoband max PANcover crops) (2ppl)
- (Tualatin) 2021-2022*, OR –Gales Meadow Farm (zero-immob and max PAN cover crops) (5 ppl)
- (Tualatin) 2021-2022*, OR –Stoneboat Farm (zero-immob and max PAN cover crops) (3 ppl)
- (Tualatin) 2021-2022*, OR –La Finquita del Buho (zero-immob and max PAN cover crops) (2 ppl)
- (Tualatin) 2021-2022*, OR –Adelante Mujeres zero-immob and max PAN cover crops) (3ppl)
- (Tualatin) 2021-2022*, OR -Square Peg Farm (zero-immob and max PAN cover crops) (2 ppl)
- 2021-2022, WA Early Bird Farm** (interseeding in late fall and over-wintering vegetables) (2ppl)
- 2021-2022, WA 21 Acres Farm** (interseeding in late fall and over-wintering vegetables) (2ppl)
* Zero-immobilization trials (zero-immob) and maximum plant-available nitrogen (max PAN) trials are funded by a complementary grant from Tualatin Soil and Water Conservation District (2019-2022). Collaborators were interested in cereal cover crops because of low seed cost, weed competition and high biomass, but want to avoid nitrogen immobilization. We are testing different ratios of triticale and common vetch to determine optimal seeding ratios for high biomass production that avoids nitrogen immobilization. Max PAN collaborators were interested in the most productive legumes to replace nitrogen fertilizer. We trialed several varieties of legume cover crops. In the zero-immob and max PAN trials we measure cover crop biomass and nitrogen content and predicted PAN release or N immobilization with the OSU Organic Fertilizer & Cover Crop Calculator. Degree-day accumulation was calculated for PAN comparisons of the legumes in order to account for different seeding and termination dates and weather conditions in the on-farm trials.
**Cover crop interseeding: collaborators were interested in interseeding cover crops into late fall and over-wintered vegetable crops. With other funds we purchased or acquired walk-behind interseeders and a tractor-mounted interseeder and identified cash crops and cover crop species to test in Oregon, Washington and Idaho.
99 producers were involved with or toured the on-farm demonstrations in 2020-2021. Videos of the WA trials were produced to share results more widely since COVID-19 restrictions prevented in-person field days. These videos were launched in early 2021. They have been viewed 197 times.
Educational & Outreach Activities
- Nitrogen management in organic vegetables (Jan. 21), online Specialty Seed Growers of Western Oregon annual meeting. 18 participants.
- Cover crops and soil health in vegetable rotations: On farm trials and nitrogen (Feb. 19), online OSU Small Farms Conference: cover crops in vegetable rotations session. 75 participants.
- Cover crops and nitrogen management in organic vegetables (Sep. 22). At OSU-North Willamette Research & Extension Center Ag Innovations Conference. 20 participants.
- Predicting cover crop N release: current tools and future prospects (Nov. 16). At Pacific Northwest Vegetable Growers Association Annual Conference 80 participants.
Despite COVID-19 restrictions, our project was able to reach farmers and agricultural professionals through on-farm trials, 2 webinars, and 2 field tours in 2020. Videos were produced that featured some of the on-farm trials and these were finalized and made available in early 2021.
Outcomes were evaluated for our 2020 Cover Crop Roundtable, which was moved from in-person to a webinar format, with a post-event survey. Based on the post-event evaluation (n=13), most participants had 2 or less years of experience with cover crops. 73% of attendees greatly increased their knowledge about the economics of cover crops and 82% greatly increased their knowledge about incorporating cover crops in rotation and nutrient cycling with cover crops; 54% greatly increased their knowledge about cover crop selection; 64% greatly increased their knowledge about cover crops and soil health; and 82% planned to make changes in their use of cover crops following the event.
One on-farm research participant shared the following statement regarding what she had learned from participating in research on her farm:
“This project is one of the most eye opening and exciting parts of our farming career in the last 32 years!”
We have forged stronger NRCS partnerships (i.e. Steven Lee and NRCS cover crop evaluation protocols).
Engagement with the Western Cover Crops Council
- WCCC members in OR, WA, ID and CA are developing a new NRCS CIG On-farm trials proposal to continue on-farm cover crop trials and using results to inform adaptation of a cover crop selection tool to the western region.
- WCCC members in OR, WA and CA are developing a new WSARE R&E pre-proposal to adapt CC-NCALC to the western region and engage producers in adoption of cover crops and ecological nitrogen management