https://doi.org/10.1029/2025JG009647

Arain, M. Altaf; Hussain, Nur; Kreibich, Liam; Brodeur, Jason; Nesic, Zoran (2026) Carbon, Water, and Energy Flux Dynamics in Different Cropping Systems in the Great Lakes Region, Journal of Geophysical Research: Biogeosciences, https://doi.org/10.1029/2025JG009647

This study examined carbon (C), water, and energy exchanges across different cropping systems in the Great Lakes region using eddy covariance (EC) fluxes from an agricultural flux tower site (CA-TPA) in southern Ontario, Canada. The site was cultivated with corn in 2020 and 2021, sweet potato in 2022, and tobacco in 2023. The site was a strong C sink during the corn years, with annual net ecosystem productivity (NEP) values of 538 ± 4.9 and 301 ± 3.7 g C m?2 yr?1 in 2020 and 2021, respectively. In contrast, it became a C source in 2022 under sweet potato, exhibiting an annual NEP of ?86 ± 2.1 g C m?2 yr?1. Under tobacco in 2023, the site transitioned to a weak carbon sink, with an annual NEP of 29 ± 1.6 g C m?2 yr?1. Crop yield (CY) was 537 and 491 g C m2 for corn in 2020 and 2021, respectively, 118 g C m2 for sweet potato in 2022, and 124 g C m2 for tobacco in 2023. It resulted in an annual net ecosystem carbon balance (NECB) of 1, ?190, ?205, and ?95 g C m2 yr?1 for 2020, 2021, 2022, and 2023, respectively, indicating an overall net C loss from all three cropping systems after accounting for harvested biomass. Annual evapotranspiration (ET) totals were 661, 727, 745, and 722 mm yr?1 for 2020–2023, accounting for approximately 58%, 72%, 78%, and 74% of annual precipitation. The study results provide insights to support climate-smart crop management practices in the region.

This study measured carbon, water and energy exchanges at a new agricultural flux tower site in Southern Ontario, Canada, known as CA-TPA, from 2020 to 2023. The site grew corn in 2020–2021, sweet potato in 2022, and tobacco in 2023. During the corn years, the site acted as a strong net carbon sink, with annual NEP values of 538 and 301 g C m?2 yr?1, indicating greater carbon uptake than release. In contrast, sweet potato in 2022 shifted the site to a net carbon source (?86 g C m?2 yr?1), while tobacco in 2023 resulted in a weak net carbon sink (29 g C m?2 yr?1). Crop yield (CY) was 537 and 491 g C m2 for corn in 2020 and 2021, respectively, 118 g C m2 for sweet potato in 2022, and 124 g C m2 for tobacco in 2023. It resulted in an annual net ecosystem carbon balance (NECB) of 1, ?190, ?205, and ?95 g C m2 yr?1 for 2020, 2021, 2022, and 2023, respectively, indicating an overall net carbon loss from these cropping systems after accounting for harvested biomass. This study provides baseline data to support climate smart farming.

https://doi.org/10.1029/2025JG009647