Supplemental information for "Comparative Analysis of Conventional and Sod-Based Rotational Production Systems: Impacts on Yield and Nitrogen Dynamics"

Excessive nitrate-nitrogen (NO₃-N) loading from agricultural practices is a concern for areas like Florida, where total maximum daily load (TMDL) standards for nitrates are in place to protect water quality. Both organic and inorganic nitrogen fertilizers contribute to this issue, particularly in systems with conventional crop rotations. This study aimed to evaluate the effectiveness of rotational production, including sod-based rotations, as a best management practice (BMP) to reduce nitrate-nitrogen leaching and improve nitrogen use efficiency while maintaining crop productivity. A four-year field study (2019–2022) was conducted at the North Florida Research and Education Center-Suwannee Valley in Live Oak, FL. The nitrate-nitrogen systems included two conventional rotations: a maize (Zea mays) - peanut (Arachis hypogaea) rotation and a maze - carrot (Daucus carota) - peanut rotation. Additionally, there were two sod-based rotations: one involving two years of bahiagrass (Paspalum notatum) followed by maize and peanut, and another involving two years of bahiagrass followed by maize, carrot, and peanut. Results indicated that the Sod-based rotations reduced nitrate-nitrogen leaching by 39% in maize and 46% in peanut compared to conventional rotations. Nitrogen use efficiency increased by 13% in maize under sod-based systems, though conventional rotations produced higher short-term crop yields over the four-year study period. Maize yields showed a normalized root mean square error (nRMSE) of 7.5%, and peanut yields had an nRMSE of 8.7%. Sod-based systems had lower, more stable soil mineral N levels during the 2021 maize season, peaking at 47 kg N ha⁻¹, compared to 94 kg N ha⁻¹ in conventional rotations. In conventional maize rotation, NO₃-N leaching was strongly correlated with rainfall (R² = 0.85, RMSE = 12 kg ha⁻¹, p-value