Greenhouse gases in intensive agriculture: contributions of individual gases to the radiative forcing of the atmosphere
Date
2000-09-15
Authors
Harwood, Richard R., author
Paul, Eldor A., author
Robertson, G. Philip, author
American Association for the Advancement of Science, publisher
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Abstract
Agriculture plays a major role in the global fluxes of the greenhouse gases carbon dioxide, nitrous oxide, and methane. From 1991 to 1999, we measured gas fluxes and other sources of global warming potential (GWP) in cropped and nearby unmanaged ecosystems. Net GWP (grams of carbon dioxide equivalents per square meter per year) ranged from 110 in our conventional tillage systems to -211 in early successional communities. None of the annual cropping systems provided net mitigation, although soil carbon accumulation in no-till systems came closest to mitigating all other sources of GWP. In all but one ecosystem, nitrous oxide production was the single greatest source of GWP. In the late successional system, GWP was neutral because of significant methane oxidation. These results suggest additional opportunities for lessening the GWP of agronomic systems.
Description
Publisher version: http://www.jstor.org/stable/3077685.
Rights Access
Subject
agriculture
global fluxes
CH4
radiative forcing
soil C sequestration
N2O
CO2