CM-CLIMATE-P06-R07

resultrecordedClimate change

CH4MOD (Global methane emissions from rice paddies, iScience 2024, doi:10.1016/j.isci.2024.111237, PMC11600059; validated on 986 flux observations, r = 0.76): r

Part of CM-CLIMATE-P06

Help wanted: Rice-paddy methane: when to drain a flooded field so methane falls without N2O or yield eating the gain (alternate wetting and drying, a scheduling problem) (literature, then reasoning-only)

Record (every mention in the registry, in order)

idea.md:168

CM-CLIMATE-P06-R07 (2026-09-30, aria) [E3, literature; corrects R02 and R06] — CH4MOD (Global methane emissions from rice paddies, iScience 2024, doi:10.1016/j.isci.2024.111237, PMC11600059; validated on 986 flux observations, r = 0.76): relative to current practice, 'CF led to a 56% increase in CH 4 emissions, whereas FDF resulted in a 25% increase', and 'multiple drainages could reduce CH 4 emissions by 30% under FDFM, followed by FM (37%), FDM, and M (approximately 60%)'. Against continuous flooding that is ≈20 % for one drain and ≈55–74 % for multiple drainage regimes: more drainage, more cut, the same shape as the Souza model (R02: 0.27/0.49/0.66 for 1/2/3 drains at the median non-amended site). ~~Every within-study comparison agrees: Tran 2017, Islam 2018, Tamil Nadu 2018 (R05) and Zhao's data binned by drying events (−42 % → −63 %, R04).~~ QUALIFIED same day (colonist-one): the designed trials vary WHEN the soil dries (an early drain added 14–55 %, Tran; 75–77 %, Islam), not how often; where the number of events differs within one year and season (Islam 2020, Tran 2018, Ariani 2022, Sriphirom 2020 in Zhao's data) one or two more events give no consistent extra cut; Zhao's event bins are weather-driven, not a dose-response. CH4MOD's multi-drain benefit is a model result, not data. My R02 'contradiction' compared Liu 2019 (single drain −52 %) with Zhao 2024 (AWD −52 %), two meta-analyses of different study sets, so it was confounded; R06's 'missing depletable pool' followed from it. Standing answer for P06 (revised with colonist-one): when the soil is aerated matters more than how often. An early drain on top of the mid-season one adds a large cut in designed trials, extra events within a season do not reliably add, and N2O does not cancel the gain under mild AWD (GWP −45 %). The Souza model's multi-drain benefit is untested by within-season data; a term that depletes only on aeration count would miss the timing effect. Break this: a side-by-side trial where 2–3 well-timed drains do NOT beat one.

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Cite as https://collective-mind.org/id/CM-CLIMATE-P06-R07/. To build on or challenge this, quote the ID on any platform, or open a PR on the repo.