HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (16) Citing Articles via Google Scholar Google Scholar Articles by Lu, Y. Articles by Huang, C. Search for Related Content PubMed Articles by Lu, Y. Articles by Huang, C. Agricola Articles by Lu, Y. Articles by Huang, C.

DIVISION S-3-SOIL BIOLOGY & BIOCHEMISTRY

Dynamics of Dissolved Organic Carbon and Methane Emissions in a Flooded Rice Soil

^a Laboratory of Soil Biology and Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, 464-8601 Japan
^b Fraunhofer Institute for Atmospheric Environmental Research, Garmisch-Partenkirchen, Germany
^c UFZ-Center for Environmental Research, Department of Soil Sciences, Theodor-Lieser Strasse 4, D-06120 Halle, Germany
^d College of Resources and Environmental Sciences, Zhejiang University, Zhejiang, China

lyahai{at}nuagr1.agr.nagoya-u.ac.jp

Limited information is available on the dynamics of dissolved organic C (DOC) and its relationship with CH₄ emissions in flooded rice (Oryza sativa L.) soils as affected by rice cultivar. Greenhouse and laboratory experiments were conducted to determine root C release in culture solution, DOC and dissolved CH₄ concentration in soil solution, and CH₄ emission in a flooded soil planted with three rice cultivars. Soil solutions were sampled in the root zone (soil surrounding rice roots) and the non-root zone (soil outside the root zone). The release of root exudates increased in the order: IR65598 (new plant type) < IR72 (modern cultivar) < Dular (a traditional cultivar). Correspondingly, DOC concentrations in the root zone and CH₄ emission rates increased. The dynamics of DOC and dissolved CH₄ differed greatly between the root zone and the non-root zone. Dissolved organic C in the root zone increased with plant growth and reached maximum (13–24 mmol C L^-1) between rice flowering and maturation (Week 11–13), whereas DOC in the non-root zone remained low (1–5 mmol C L^-1) throughout the growing season. Similarly, dissolved CH₄ concentrations in the root zone increased sooner and were greater (mean 138 µmol CH₄ L^-1) than those in the non-root zone (mean 97 µmol CH₄ L^-1). The seasonal patterns of CH₄ emissions closely followed the dynamics of DOC concentrations in the root zone. The results suggest that (i) DOC pool in the root zone of rice plants is enriched by root-derived C; (ii) the rates of CH₄ emissions are positively correlated with the dynamics of DOC in the root zone; (iii) the intercultivar difference in root C releases is responsible for the intercultivar difference in DOC production, and consequently in CH₄ flux.

Abbreviations: DOC, dissolved organic C • GC, gas chromatograph • PI, panicle initiation • SOC, soil organic C

This article has been cited by other articles:

				K. Yu, F. Bohme, J. Rinklebe, H.-U. Neue, and R. D. DeLaune Major Biogeochemical Processes in Soils-A Microcosm Incubation from Reducing to Oxidizing Conditions Soil Sci. Soc. Am. J., June 29, 2007; 71(4): 1406 - 1417. [Abstract] [Full Text] [PDF]