Premium
Soil Air Carbon Dioxide and Nitrous Oxide Concentrations in Profiles under Tallgrass Prairie and Cultivation
Author(s) -
Sotomayor David,
Rice Charles W.
Publication year - 1999
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1999.00472425002800030008x
Subject(s) - loam , nitrous oxide , carbon dioxide , soil water , environmental science , environmental chemistry , chemistry , agronomy , hydrology (agriculture) , soil science , biology , geology , organic chemistry , geotechnical engineering
Assessing the dynamics of gaseous production in soils is of interest because they are important sources and sinks of greenhouse gases. Changes in soil air carbon dioxide (CO 2 ) and nitrous oxide (N 2 O) concentrations were studied in a Reading silt loam (fine‐silty, mixed, mesic Typic Argiudolls) under prairie and cultivation. Concentrations were measured in situ over a 17‐mo period to a depth of 3 m. Multilevel samplers permitted collection of gases with subsequent measurement by gas chromatography in the laboratory. Soil air N 2 O concentrations were near atmospheric levels for a majority of the study period in the prairie site (0.184–2.25 µL L −1 ) but were significantly higher in the cultivated site (0.257–7.56 µL L −1 ). Annual mean N 2 O concentrations were 0.403 and 1.09 µL L −1 in the prairie and cultivated sites, respectively. Soil air CO 2 annual mean concentrations were 1.56 × 10 4 and 1.10 × 10 4 µL L −1 and ranged from 0.096 × 10 4 to 6.45 × 10 4 µL L −1 and 0.087 × 10 4 to 3.59 × 10 4 µL L −1 in the prairie and cultivated sites, respectively. Concentrations generally increased with depth, with maximum soil air N 2 O and CO 2 concentrations at 1.0 m in the prairie site and 0.5 m in the cultivated site. Nitrous oxide in the cultivated site and CO 2 at both sites did not change markedly over winter months, but CO 2 and N 2 O concentrations reached maximums during the summer months and decreased as the year progressed. Although soil air concentrations peaked and decreased faster at shallower depths, deeper depths exhibited relative maximum concentrations for longer time periods.