There is growing interest in use of cover crops for benefits including reduction of soil erosion, managing soil moisture, weed suppression, and increasing long-term soil productivity. While there is on-going research in the Red River Valley and at the CREC with use of winter rye as a cover crop with soybean, research expanded to south-central ND would be useful for this region’s soybean farmers as they consider adapting this management practice. In addition, it would be useful for all ND farmers to use proper seeding rates of rye based on fall establishment dates and impact on soil cover and moisture levels, weed management, and soybean yield. Data from these selected soybean studies, which are within the scope of ND Soybean Council research priorities – soil and water management, will be shared with ND farmers and crop advisers to potentially increase profitably of soybean production and improve soil productivity.

*Study 1. At the CREC Tri-county research site (Wishek area), will examine soybean performance with winter rye as a preplant cover crop compared to conventional production. Main emphasis will be determining normal rye termination time to utilize the benefits of the cover crop while maintaining soybean yield in a normally dry environment.
*Study 2. At the CREC, will use winter rye seeding rates and fall date combinations, and measure rye plant population and ground cover, soil moisture levels, and weed suppression during the following soybean production period.

The two studies will aid in updating research-based recommendations on use of winter rye with soybean. Study 1 will help encourage south-central ND farmers to consider using rye as part of their soybean management and aid in the decision when to terminate the cover crop. Study 2 will aid farmers in determining proper rye seeding rates based on their goals with the cover crop while maintaining soybean yield.

Updated January 6, 2021:
FY 2021 Mid-Year Report ND Soybean Council
Winter Rye Cover Crop Management Techniques for Soybean
Objectives of the research:

1. Winter rye as a preplant cover crop before soybean: Will measure soybean performance with winter rye compared to conventional production in south-central ND (Wishek area).
2. Winter rye seeding dates and rates: What is the best combination of seeding date and rate to reach farmer goals with rye as a preplant cover crop with soybean based on impact on soil cover and moisture, weed management, and soybean yield?
Completed work:
• Trial 1: Trial was successfully conducted at the Tri-county off-station research site. Treatments: 1) soybean grown without rye; 2) rye terminated with glyphosate 12 days before soybean seeding; and 3) rye terminated with glyphosate two days after soybean seeding.
• Trial 2: Trial was successfully conducted at the Carrington Research Extension Center. Treatments: Winter rye was seeded on September 26 and November 1, 2019 at 25, 50 and 75 lb/A (six treatments). Soybean were planted on May 29, immediately followed by rye termination with glyphosate, and harvested on September 17.
Preliminary results:
• Trial 1: Soybean seed yield was statistically similar between conventional production check (45.0 bu/A) and rye terminated prior to soybean seeding (40.0 bu/A), while rye termination after seeding resulted in reduced soybean yield (29.4 bu/A). About 20 people viewed and heard discussion about the trial during the July 27 tour.

• Trial 2: Rye plant density ranged from 162,200 plants/A with late and low seeding rate to 1,149,700 plants/A with early and high seeding rate. The second year of research in this multi-year study indicates an advantage in foxtail and kochia suppression prior to soybean planting with early fall seeded rye. Also, performance of soybean (plant development, and seed yield and quality) was not affected by rye seeding date or rate.
Work to be completed:
• Research reports written and shared with audiences using CREC website, ND Soybean Council 2020 annual research report, and other electronic options (e.g. CREC Center Points blog, Facebook).
• Data slides developed and presented for farmers and crop advisers during 2020-21 winter meetings and summer tours.

Updated June 30, 2021:

View uploaded report

View uploaded report 2

Winter rye cover crop management techniques for soybean
Research:
• Trial 1: Commenced in 2018 at the Tri-county research site with the following treatments: 1) soybean grown without rye as a cover crop; 2) rye terminated with glyphosate one month before soybean planting; and 3) rye terminated with glyphosate at soybean planting.
• Trial 2: Conducted at the CREC starting in the fall of 2018, to evaluate rye plant stands with selected seeding rates and fall dates, and effect on following season’s ground cover, soil moisture, weed suppression, and soybean yield.

Why the research is important to ND soybean farmers:
The goal of this project is to continue building NDSU databases on soybean yield impact with two trials examining winter rye as a cover crop prior to soybean production:
? Rye as a cover crop: Will winter (cereal) rye as a cover crop impact soybean yield in an arid environment while providing soil benefits compared to conventional soybean production?
? Rye fall seeding dates and rates: What is the best rye seeding rate and established stand, based on fall seeding dates and following season factors affecting soybean production including ground cover, soil moisture, and weed suppression with rye?

Findings of the research:
• Trial 1: Rye needs to be terminated 2-4 weeks before soybean planting to preserve soil moisture in an arid environment for successful soybean production.
• Trial 2: Early fall rye seeding and rates of 50 or 75 lb per acre generally provided improved ground cover and weed suppression, while maintaining soybean productivity.

Benefits/Recommendations to ND soybean farmers and industry:
• Trial 1: Timing of rye termination with glyphosate needs to be carefully considered to balance the benefits of the cover crop while preserving soil moisture for the soybean crop.
• Trial 2: Fall planting dates and rates need to be considered based on farmer goals with the cover crop as they consider soil cover and moisture, control of weeds, and performance of soybean.

*Study 1. Results will help south-central ND farmers answer the following question: Can winter rye be used to realize benefits as a cover crop with soybean without reducing seed yield in a normally arid environment?
*Study 2. Results will help farmers answer the following question: What is the best rye seeding rate based on fall seeding dates and following season factors affecting soybean production including ground cover, soil moisture, and weed suppression with rye? The information will help farmers select proper rye seeding rate and fall date based on their cover crop goals and resource management.