Fluxes of Carbon Dioxide, Nitrous Oxide, and Methane in ... - USDA

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Fluxes of Carbon Dioxide, Nitrous Oxide, and Methane in Grass Sod and Winter Wheat-Fallow Tillage Management. Anabayan Kessavalou, Arvin R. Mosier, ...
Atmospheric Pollutants and Trace Gases Fluxes of Carbon Dioxide, Nitrous Oxide, and Methane in Grass Sod and Winter Wheat-Fallow Tillage Management Anabayan Kessavalou, Arvin R. Mosier, John W. Doran,* Rhae A. Drijber, Drew J. Lyon, and O. Heinemeyer ABSTRACT Cropping and tillage management can increase atmospheric CO,, N:O, and CH4 concentrations, and contribute to global warming and destruction of the ozone layer. Fluxes of these gases in vented surface chambers, and water-filled pore space (WFPS) and temperature of survace soil were measured weekly from a long-term winter wheat (Triticiim aestivum L.)-fallow rotation system under chemical (notillage) and mechanical tillage (noninversion subtillage at 7 to 10 cm or moldboard plowing to 15 cm) follow management and compared with those from "native" grass sod at Sidney, NE, from March 1993 to July 1995. Cropping, tillage, within-field location, time of year, soil temperature, and WFPS influenced net greenhouse gas fluxes. Mean annual interrow CO2 emissions from wheat-fallow ranged from 6.9 to 20.1 kg C ha"1 d ' and generally increased with intensity and degree of tillage (no-till least and plow greatest). Nitrous oxide flux averaged