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Soil Carbon Dioxide Distribution and Flux within the Open‐top Chamber
Author(s) -
Nakayama F. S.,
Kimball B. A.
Publication year - 1988
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1988.00021962008000030003x
Subject(s) - loam , carbon dioxide , environmental science , flux (metallurgy) , soil water , calcareous , chemistry , agronomy , soil science , botany , biology , organic chemistry
Open‐top chamber use for exposing plants to various levels of CO 2 and pollutant gases is increasing in field studies. In making a C balance of cotton [ Gossypium hirsutum (L.) ‘Deltapine‐61’] for such a system, soil CO 2 fluxes were observed to be significantly greater outside than inside the chamber. To find the cause, CO 2 concentration was measured in the soil profile from 5‐ to 60‐cm depths of an Avondale clay loam [fine‐loamy, mixed (calcareous), hyperthermic Typic Torrifluvent]. The soil CO 2 contents at the various depths sampled outside the chamber were higher than those inside the chamber. The differences in concentration were observable within 2 wk after the blower used to pass ambient of CO 2 ‐enriched air through the chamber was turned on. The largest differences were present approximately 16 wk after the system had been in operation. Approximately 30 d was required for the soil CO 2 levels inside and outside the chamber to become similar after the blower was turned off. Soil water content was not a factor causing this difference because it was nearly equal at both sites. Pressure differentials inside the growth chamber resulting from the blower operation could lead to a decrease in soil CO 2 concentration and fluxes measured using the closed chamber technique.