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Methane consumption and carbon dioxide emission in tallgrass prairie: Effects of biomass burning and conversion to agriculture
Author(s) -
Tate Cathy M.,
Striegl Robert G.
Publication year - 1993
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/93gb02560
Subject(s) - environmental science , soil water , sorghum , carbon dioxide , agronomy , biomass (ecology) , water content , methane , soil carbon , hydrology (agriculture) , soil science , chemistry , geotechnical engineering , organic chemistry , biology , engineering
Consumption of atmospheric methane and emission of carbon dioxide by soils were measured on unburned and annually burned tallgrass prairie and on adjacent wheat and sorghum agricultural plots in Kansas. Profiles of CH 4 and CO 2 concentration with soil depth were also measured. Overall patterns of CH 4 consumption by soils varied temporally, with soil depth and land use. Mean CH 4 consumption for the 200‐day sampling period was −1.02 mg CH 4 m −2 d −1 (SE=0.13, n=41) for burned prairie, −0.63 (SE=0.09, n=45) for unburned prairie, −0.85 (SE=0.20, n=36) for wheat, and −0.45 (SE=0.08, n=40) for sorghum. Less than 20 % of the variance in CH 4 consumption was explained by soil temperature and/or moisture content. Overall patterns of CO 2 emission from prairie and agricultural soils varied temporally, but not among land use. Mean CO 2 emission for the 200‐day sampling period was 15.7 g CO 2 m −2 d −1 (SE=1.8, n=41) for burned prairie, 14.5 (SE=1.3, n=45) for unburned prairie, 13.9 (SE=2.1, n=36) for wheat, and 10.3 (SE=2.1, n=40) for sorghum. More than 70% of the variance in prairie CO 2 emission rate was explained by soil temperature and moisture. Crop management practices influenced the timing of CO 2 emission from agricultural plots but not the net annual rate of emission. Methane concentrations generally decreased and CO 2 concentrations increased with soil depth, and the magnitude of CH 4 and CO 2 flux generally increased with increased magnitude of the soil gas concentration gradient. Fertilization of agricultural fields had no measured effect on CH 4 or CO 2 flux or on soil gas concentrations.