Updated March 31, 2022:
As farmers in the far northeast region look for ways to reduce feed costs and diversify their operations, soybeans are becoming increasingly popular. However, these farmers need region specific information to help them succeed in producing high yielding soybean crops while protecting the natural resources on and around their farms.
This project met several of the Eastern Soybean Growing Region Board research priorities including a focus on high yielding soybeans and soil health.
All projects were conducted in the most northwestern corner of VT. The soil type is characterized as a silt loam with 1 to 2% slope. The weather during the 2021 growing season can be characterized as warm and dry. Above average temperatures and below average precipitation persisted throughout the growing season.
Objective 1 was to identify soybean varieties that produce maximum yields in the far north. The experimental design was a randomized complete block with 3 replicates. The treatments were 19 varieties with maturity groups ranging from 0.7 to 2.8.
The average yield for the entire trial was 62.3 bushels of soybeans per acre. The top performing variety yielded 73.7 bushels per acre and had a maturity grouping of 2.0. Other varieties that performed statistically similar to this top performer had maturity ratings ranging from 1.2 to 2.8.
The data from this growing season indicates that high soybean yields can be obtained from a wide range of maturity ratings in far northern regions. However, it is important to note some large differences between varieties even within similar relative maturities. For example, the three varieties with relative maturity 1.2 ranged in yield from 46.9 to 71.4 bu/acre. These data highlight the importance of utilizing local variety evaluation information in variety selection.
Objective 2 was to investigate the impact of cover crop termination method and residue or cover crop biomass level on soybean yield and soil health. The experimental design was a randomized complete block with split plots and four replicates. Main plots were cover crop termination methods including tillage, herbicide applied before planting or planting green where herbicide is applied following planting. Sub-plots were varying levels of cover crop biomass created by seeding winter rye at rates ranging from 0 to 150 lbs/acre.
The seeding rates of winter rye had little impact on the soil health and soybean yields. However, the termination treatments had a much greater influence on soybean yields. The plant green block was terminated a week later and produced statistically higher biomass compared to the other two treatments. The plant green treatment had statistically lower yields, about 1.3X less, compared to the tillage and pre-plant herbicide treatments.
As noted earlier, the entire growing season was dry. The additional cover crop biomass and longer period of growth likely dried out the soil more than the other cover crop treatments. Since rainfall was in a deficit all season, the plant-green plots may have been more water stressed than the other treatments. Average, across the season soil moisture was significantly lower in the plant green plots. This additional moisture stress may have contributed to lower yields.
Objective 3 investigated the impact of cover crop interseeding dates timed with later soybean developmental stage R6-R8 on cover crop establishment. The experimental design was a complete randomized block with four replications and the treatments were four cover crop planting dates. Annual ryegrass (var. Centurion) was interseeded into soybeans at four different planting dates: 14-Sep, 21-Sep, 28-Sep, and 4-Oct. Soybeans were harvested on 27-Oct. A week after soybean harvest, percent ground cover from the cover crop and cover crop biomass yields were measured.
The annual ryegrass planting date had no significant impact on soybean harvest. Ground cover and cover crop yields were significantly impacted by planting date. The first planting date, 14-Sep, had statistically higher ground cover, 52.9%, and dry matter yield, 1426 lbs. or 0.71 tons/acre, compared to the other three planting dates. The latest planting date, 4-Oct, had the lowest ground cover, 13.6%, and dry matter yield, 235 lbs per acre. This trial indicates that interseeding cover crops a month prior to soybean harvest will provide for timely seeding and adequate cover crop establishment with hopefully minimal impact on soybean yield.
Soybean production information and research results were shared with over 300 growers and stakeholders throughout the region. Virtual events were still largely the avenue to share education on soybeans. However, in the fall of 2021 a fall field day was held drawing 126 stakeholders. Attendees were able to walk the research plots and learn about research results. Soybean cover cropping information was shared with farmers and service providers at the annual NECCC Annual Conference with 185 attendees. These soybean research materials including full soybean project reports will be continually available to growers and other interested parties through our website and shared at relevant virtual and in-person outreach events through 2022.
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As farmers in the far northeast region look for ways to reduce feed costs and diversify their operations, soybeans are becoming increasingly popular. However, these farmers need region specific information to help them succeed in producing high yielding soybean crops while protecting the natural resources on and around their farms. This project met several of the Eastern Soybean Growing Region Board research priorities including a focus on high yielding soybeans and soil health.
All projects were conducted in the most northwestern corner of VT. The weather during the 2021 growing season can be characterized as warm and dry. The first goal was to identify soybean varieties that produce maximum yields in the far north. We were able to evaluate 19 varieties with maturity groups ranging from 0.7 to 2.8. The top performing variety yielded 73.7 bushels per acre and had a maturity grouping of 2.0. However, the data indicates that high soybean yields can be obtained from a wide range of maturity ratings in far northern regions. It is important to note some large differences between varieties even within similar maturities. For example, the three varieties in maturity group 1.2 ranged in yield from 46.9 to 71.4 bu/acre These data highlight the importance of utilizing local variety evaluation information in variety selection. The second goal was to investigate the impact of cover crop termination method and cover crop biomass level on soybean yield and soil health. A range of cover crop biomass was created by seeding winter rye from 0 to 150 lb/acre. The cover crop termination methods included tillage, herbicide applied before planting or planting green where herbicide is applied following planting. The amount of cover crop biomass had little impact on the soil health and soybean yields. However, the termination treatments had a much greater influence on soybean yields. The plant green treatment was terminated later and produced more cover crop biomass compared to the other two treatments. The plant green treatment yielded 1.3X less, compared to the tillage and pre-plant herbicide treatments. As noted earlier, the entire growing season was dry. The additional cover crop biomass and longer period of growth likely dried out the soil more than the other cover crop treatments. Since rainfall was in a deficit all season, the plant-green plots may have been more water stressed than the other treatments. Average, across the season soil moisture was lower in the plant green plots. This additional moisture stress may have contributed to lower yields. Lastly, the impact of cover crop interseeding dates on cover crop establishment and soybean yields were evaluated. The cover crop interseeding was timed to occur between the R6-R8 stages of soybean development. The interseeding occurred on 14-Sep, 21-Sep, 28-Sep, and 4-Oct. Soybeans were harvested on 27-Oct. The annual ryegrass planting date had no impact on soybean harvest. Ground cover and cover crop yields were significantly impacted by planting date. The first planting date, 14-Sep, had statistically higher ground cover, 52.9%, and dry matter yield, 1426 lbs/acre compared to the other three planting dates. The latest planting date, 4-Oct, had the lowest ground cover, 13.6%, and dry matter yield, 235 lbs/acre. This trial indicates that interseeding cover crops a month prior to soybean harvest will provide for timely seeding and adequate cover crop establishment with hopefully minimal impact on soybean yield.
Soybean production information and research results were shared with over 300 growers and stakeholders throughout the region. Virtual events were still largely the avenue to share education on soybeans. However, in the fall of 2021 a fall field day was held drawing 126 stakeholders. Attendees were able to walk the research plots and learn about research results. Soybean cover cropping information was shared with farmers and service providers at the annual NECCC Annual Conference with 185 attendees. These soybean research materials including full soybean project reports will be continually available to growers and other interested parties through our website and shared at relevant virtual and in-person outreach events through 2022.