Probabilistic assessment of cereal rye cover crop impacts on regional crop yield and soil carbon

Authors: RAI, TEERATH - University Of Illinois; LEE, NICOLE - University Of Illinois; Williams, Martin; DAVIS, ADAM - University Of Illinois; VILLAMIL, MARIA - University Of Illinois; DOKOOHAKI, HAMZE - University Of Illinois

Submitted to: Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/4/2023
Publication Date: 1/10/2023
Citation: Rai, T., Lee, N., Williams, M., Davis, A., Villamil, M., Dokoohaki, H. 2023. Probabilistic assessment of cereal rye cover crop impacts on regional crop yield and soil carbon. Agriculture. 13(1). Article 176. https://doi.org/10.3390/agriculture13010176.
DOI: https://doi.org/10.3390/agriculture13010176

Interpretive Summary: Winter cover crops (WCC) could enhance soil organic matter and reduce nutrient losses and soil erosion in the U.S. Midwest; however, adoption rate of WCC is low due to uncertainties in their economic, agronomic, and climate benefits. This research aimed to quantify the uncertainty of WCC on corn/soybean yields and soil organic matter sequestration across the state of Illinois. We found the majority of the state was responsive to cereal rye adoption and soil organic matter improvement. Also, adoption of cereal rye cover crop appeared to provide greater stability in corn production. The impact of this work is that by quantifying important uncertainties in use of WCC may facilitate WCC adoption, which will tackle climate change by sequestering carbon in tandem with improving soil quality.

Technical Abstract: Field research for exploring the impact of winter cover crops (WCCs) integration into cropping systems is resource intensive, time-consuming and offers limited application beyond the study area. To bridge this gap, we used the APSIM model, to simulate corn (Zea mays L.)-rye (Secale cereale L.)-corn-rye and corn-rye-soybean (Glycine max L.)-rye rotations in comparison with corn-corn and corn-soybean rotations across the state of Illinois at a spatial resolution of 5 km × 5 km from 2000 to 2020 to study the impact of WCCs on soil organic carbon (SOC) dynamics and crop production. By propagating the uncertainty in model simulations associated with initial conditions, weather, soil, and management practices, we estimated the probability and the expected value of change in crop yield and SOC following WCC integration. Our results suggest that integrating cereal rye into the crop rotations imparted greater yield stability for corn across the state. It was found that the areas with low probability of increase in SOC (p < 0.75) responded equally well for soil carbon sequestration through long term adoption of WCCs. This study presents the most complete uncertainty accounting of WCC benefits across a broad region and provides greater insights into the spatiotemporal variability of WCCs benefits for increasing WCC adoption rate.