Folahanmi Adeyemi

Ph.D. Level Student
Southern Illinois University Carbondale
Advised by Dr. Amir Sadeghpour

Soybean Performance and Soil Nitrous Oxide Emissions After Six and Eight Years of Tillage and Cover Cropping

A combination of no-till with winter cereal cover crops such as winter rye (Secale cereale L.) offers multiple benefits including improved soil water holding capacity, infiltration, and carbon (C) sequestration. However, their impact on soybean yield, yield component, and soil nutrient dynamics, and nitrous oxide emissions should be assessed to be reliably recommended to growers in Sothern Illinois. Therefore, we evaluated soybean performance in 2020 and 2022 growing seasons following four treatment combinations with two tillage factors (no-till and conventional chisel-disk) and two cover crops (winter rye and a no-cover crop control) arranged in factorial design with three replications. Our data indicated that soybean grain yield was similar among all tillage-cover crop combinations despite some differences in plant height in 2020. Leaf area index and normalized difference vegetation index (NDVI) were also similar among treatments over the two growing seasons. While cover crop did not influence soybean shoot biomass accumulation, it impacted soybean root biomass indicating that winter rye not only add C to the system but also promote greater C inputs in soybean. In 2020, Among treatments, N2O-N was similar among all treatments except for no cover crop tillage treatment which had lower N2O-N than cover crop tillage and no cover crop no-till treatments. In 2022, all treatments had similar N2O-N fluxes. We concluded that a combination of no-till with winter rye could provide soil benefits with no negative impact on soybean performance or N2O-N losses.