Greenhouse gas emissions altered by the introduction of a year‐long fallow to continuous rice systems
Year: 2025
Type: article
Abstract: Rice ( Oryza sativa L.) production in California follows a norm of mono‐cropping with little to no rotations or fallows. Both winter droughts, which lead to water restrictions, and spring rains, which inhibit field machinery operations, have resulted in increased fallow frequencies, where no crop is grown during the summer growing season. A 3‐year field study was conducted to investigate summer and winter greenhouse gas (GHG) emissions (CH 4 and N 2 O) in three treatments: continuous rice (CR), rice following the introduction of a year‐long fallow (FR), and the fallow phase (F). Summer CH 4 emissions were lower in FR than CR in 2 out of 3 years, averaging a 33% reduction across years. Particulate organic carbon and mineral‐associated organic carbon levels in CR and FR were similar in the year with no treatment effect on CH 4 emissions—potentially due to differences in residue management. There were negligible summer CH 4 emissions in F. Summer N 2 O emissions were low for all three treatments. Summer global warming potentials (GWP) accounted for more than 96% of annual GWP in CR (13,937 kg CO 2 eq ha −1 ) and FR (9,236 kg CO 2 eq ha −1 ). For F, the winter season accounted for 94% of the annual GWP (413 kg CO 2 eq ha −1 ) due to N 2 O emissions. Overall, this study provides a valuable resource for quantifying changes in GHG emissions when fallow periods are introduced into rice monoculture in California.
Source: Journal of Environmental Quality
DOI: 10.1002/jeq2.70055
Language: English
Subfield: Soil Science
Domain: Life Sciences
Open Access status: hybrid
Estimated APC paid: $1,910
Funder: California Rice Research Board
Award: G2211687913
OpenAlex ID: W4411498473