2020
Uncovering Winter Crop Effect on Soybean Production in North Carolina
Category:
Sustainable Production
Keywords:
AgricultureBiodiversityCarbonField management Land Use SustainabilityU.S. Soy reputation
Lead Principal Investigator:
Rachel Vann, North Carolina State University
Co-Principal Investigators:
Project Code:
19-102
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:

North Carolina growers can effectively produce various winter crops prior to soybeans. The appropriate soybean maturity group selection following various winter crops requires further investigation and the effects of various winter crops on diverse aspects of soybean production have not been comprehensively investigated in North Carolina. This study compares soybeans following five winter crop scenarios: wheat for grain, rapeseed for grain, pea for grain, cereal rye as a cover crop, and cereal rye/crimson clover as a cover crop mixture, to fallow. Data collected includes soybean emergence, soil moisture, soil temperature, nitrogen availability, disease prevalence, insect prevalence and soybean yield. Efforts include economic analyses on the various winter crop scenario/soybean maturity group combinations.

Key Benefactors:
farmers, agronomists, extension agents

Information And Results
Project Deliverables

Final Project Results

Producing a winter crop before soybean is a common practice in North Carolina. Traditionally, wheat has been the primary winter crop grown in the state prior to soybean, however, other emerging winter crop scenarios include rapeseed and cover crops. With new winter crop scenarios increasing in popularity across the region, investigation into rotational impact on soybean and optimal soybean MG use is merited. This experiment was conducted in five
environments across North Carolina in 2019 and 2020. Main plot treatments included cereal rye as cover crop, cereal rye/crimson clover as cover crop mixture, May fallow, wheat for grain, rapeseed for grain, and a June fallow. Sub-plot treatments included soybean MG III, V, and VII. Data collected included cover crop/residue biomass, winter crop grain yields, soybean stand, soil moisture, soil temperature, N availability, soybean yield, and soybean seed quality. Cereal
rye and cereal rye/crimson clover mixture cover crops produced the most biomass across all environments and sometimes soybean stand was reduced behind these cover crops. Rotation impacted soil temperature and soil moisture across most environments at planting and soybean growth stage V2. Nitrogen dynamics were typically impacted by rotation but not MG. Despite observed differences in soybean stand, soil temperature, soil moisture, and N dynamics
between the various rotational scenarios, soybean yield was typically similar between the rotations highlighting the complexity of these rotations and their impact on soybean yield.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.