No-tillage effects on soil CH4 fluxes: A meta-analysis

Abstract No-tillage (NT) has widely been promoted as a conservation practice that also offsets agriculture-driven greenhouse gases and boosts agroecosystem performance. While most studies have focused on the effects of no-till on nitrous oxide and carbon dioxide fluxes, much less attention has been paid to the impacts on methane (CH4) emissions. We conducted a meta-analysis to determine whether tillage management (conventional till, CT vs. NT) affects soil CH4 fluxes, and what management and environmental conditions regulate the effect. The regulating factors we identified include crop, climatic zone, soil class and experiment age (i.e. years since beginning NT). Our study included 41 papers, with a total number of 90 case studies, that covered arable lands of all five continents. On average, NT significantly decreased CH4 emissions from paddy fields, from 12.39 to 9.55 mg m−2 h-1 (p