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Quantifying greenhouse gas (GHG) emissions in agricultural settings has become critically important in determining the magnitude of agricultural impacts on global climate change. Methane (CH4) is a leading GHG emitted from rice (Oryza saliva L.) production and, since soil organic matter (SOM) serves as a substrate for methanogenesis, understanding the relationship between SOM and CH4 emissions will be essential for attenuating the excessive release of CH4 to the atmosphere from rice production. The objective of this field study was to evaluate the effects of SOM on CH4 emissions from rice grown under a full-season flood across several silt-loam soils in eastern Arkansas. Eight soils were collected from various locations around east-central Arkansas to represent a SOM gradient (22.1 to 51.0 Mg ha(-1) in the top 10 cm) for this field study. Approximately 0.08 m(3) of soil were placed in plastic bins that were buried in a single bay with the pure-line rice cultivar ('LaKast') transplanted into each bin and grown to harvest maturity under a full-season flood. Season-long, area-scaled CH4 emissions ranged from 63 to 1521 kg CH4-Cha(-1) season(-1) for in-situ and undisturbed field-plot soil and native prairie soil, respectively, and differed (P< 0.01) among the soils evaluated. Rice grown in soil from under a managed grassland, which had the largest SUM content in the top 10 cm, produced the second largest CH4 emissions (1166 kg CH4-Cha(-1) season(-1)). Methane emissions increased linearly (P < 0.05) with increasing SOM and total carbon concentration (R-2 = 0.81 and 0.85, respectively). Greater understanding of the influence of SUM on CH4 emissions is essential for assessing GHG impacts from rice production and for refining predictions of CH4 and total GHG emissions. (C) 2018 Elsevier B.V. All rights reserved.