Carbon Turnover Kinetics with Depth in a French Loamy Soil

Abstract : Soil C dynamics below the plow layer have been little studied, in spite of proven large C stocks and suspected large C stabilization potential. The objective of the present study was to determine C-turnover kinetics throughout the 1-m profile of a cultivated loam soil of the Paris basin, France. The soil 13C signature was determined to depths of 1.05 m in 32 replicated plots having received from 0 to 10 yr of maize after wheat. Above- and below-ground maize-residue biomass inputs were estimated throughout the 10-yr period. After 10 yr, maize-derived soil organic carbon (SOC) constituted about 10, 5, and 2% of the total SOC at 15-, 50-, and 100-cm depths, respectively. About one-third of recently deposited maize-derived SOM present in the 1-m soil profile was retrieved below the Ap horizon. The ratios of maize-derived soil C to the cumulative maize above- and below-ground inputs over the 10-yr period averaged 17% across the soil profile. This ratio was lower in the Ap horizon (i.e., 13%) than in deeper soil horizons. Circumstantial evidences suggest that the distribution profile of recently deposited maize-derived C was influenced by fine root activities, bioturbation, and dissolved organic carbon (DOC) transport, the latter being substantiated by a high correlation (r2 = 0.86) between SOC contents and amorphous Fe + Al contents. In conclusion, our study stresses the need to take into account the full 1-m soil profile in C sequestration studies.
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Soil Science Society of America Journal, Soil Science Society of America, 2006, 70, pp.2097-2105. 〈10.2136/sssaj2006.0056〉
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https://hal-bioemco.ccsd.cnrs.fr/bioemco-00176222
Contributeur : Claire Chenu <>
Soumis le : mardi 2 octobre 2007 - 22:09:07
Dernière modification le : mercredi 4 juillet 2018 - 14:00:01

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Daniel P. Rasse, Jan Mulder, Christophe Moni, Claire Chenu. Carbon Turnover Kinetics with Depth in a French Loamy Soil. Soil Science Society of America Journal, Soil Science Society of America, 2006, 70, pp.2097-2105. 〈10.2136/sssaj2006.0056〉. 〈bioemco-00176222〉

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