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ARS Home » Southeast Area » Jonesboro, Arkansas » Delta Water Management Research » Research » Publications at this Location » Publication #357387
Research Project: Preserving Water Availability and Quality for Agriculture in the Lower Mississippi River Basin

Location: Delta Water Management Research

Title: Methane Flux Measurement in Rice by Static Flux Chamber and Eddy Covariance

Author
item Reba, Michele
item FONG, BRYANT - Orise Fellow
item RIJAL, ISHARA - Arkansas State University
item Adviento-Borbe, Arlene
item Chiu, Yin-Lin - Jack
item Massey, Joseph

Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/23/2020
Publication Date: 11/16/2020
Citation: Reba, M.L., Fong, B.N., Rijal, I., Adviento-Borbe, A.A., Chiu, Y., Massey, J. 2020. Methane Flux Measurement in Rice by Static Flux Chamber and Eddy Covariance. Agrosystems, Geosciences & Environment. https://doi.org/10.1002/agg2.20119.
DOI: https://doi.org/10.1002/agg2.20119

Interpretive Summary: Rice cultivation produces methane (CH4) gas due to flooded field conditions and plant structure. Methane is a greenhouse gas with multiple times the global warming potential of CO2. Emissions of CH4 were measured with two techniques-static flux chamber (SFC) and eddy covariance (EC) on typically managed rice fields in the central southern United States. The measured values were similar early and late in the season but varied more widely during the mid-season. These findings improve our understanding of methane emissions at the field scale under typical rice production practices and reduce uncertainties in current estimates of methane emissions from agriculture. These findings should be of interest to climate modelers and those who attempt to quantify agricultural sustainability.

Technical Abstract: Rice cultivation produces methane (CH4) gas due to flooded field conditions and plant structure. CH4 fluxes were measured using static flux chamber (SFC) and eddy covariance (EC) techniques from flooded rice systems under continuous flooded (CF) irrigation practices. The field-scale study was conducted in NE Arkansas during the 2015 and 2016 growing seasons (May-August). The objectives were to quantify differences between SFC and EC measurements, and correlate flux measurements with growth stage and cropping history. SFC daily fluxes were not statistically different than EC-daily average fluxes (slope=1.33-1.88, p = 0.108) or EC-morning average fluxes from 08:00-10:00, which was close to the SFC collection times (slope=0.92-1.97, p = 0.275). The total seasonal emissions from the study fields ranged from 50-156 kg CH4 ha-1 season-1. SFC and EC-daily flux measurements were similar early (p = 0.382) and late (p = 0.543) in the season, but statistically different mid-season (p < 0.001) with SFC consistently reporting greater fluxes. The variation in emissions between both fields and experiment years were found to be related to previous crops and weather conditions during the growing season rather than soil type. These findings improve our understanding of CH4 emissions at the field scale under typical production practices and add to the growing body of knowledge related to agricultural greenhouse gas measurements which will help improve agricultural sustainability.