Response of CO2, N2O, and CH4 fluxes to contour tillage, diversion terrace, grassed waterway, and tile drainage implementation
Driscoll, B. A., M.Krzic, L.P. Comeau, B.N.I. Eskelson and S. Li. 2025.
Abstract
In this study we evaluated CO2, N2O, and CH4 fluxes in two integrated best
management practices (BMPIs) comprised of the following individual practices:
diversion terraces (DT), grassed waterways (GW), and contour tillage (CT) [i.e.,
DTGW]; and DT, GW, CT, and tile drainage (TD) [i.e., DTGW TD], relative to CT
that served as a control. It was anticipated that due to its effects on soil water
redistribution and soil temperature, diversion terraces and grassed waterways
would influence the pattern of greenhouse gas (GHG) emission. This is the first
study in the world linking such erosion control structures with subsurface
drainage. Cumulative CO2 emissions were greatest in DTGW in both 2020 and
2021. In 2019, DTGW TD N2O emissions were significantly lower than CT and
DTGW. N2O emissions were highest in DTGW in 2020 and 2021, though not
statistically significant. There were no significant differences in CH4 in any year.
Soil in all BMPIs acted as a weak CH4 sink during the study period. This study
demonstrated that the addition of TD to DT and GW significantly reduced the loss
of stored carbon (as CO2) relative to undrained DT and GW, while also not
emitting significantly more carbon than CT, in the initial years after
implementation. Results were similar with respect to the loss of nitrogen, as
N2O, where undrained DT and GW generally emitted more N2O in the first years
after implementation.
Key Words
potato production, beneficial management practices, greenhouse gas, Atlantic Canada, soil carbon, soil health
