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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Short-term temporal changes of bare soil CO2 fluxes after tillage described by first-order decay models

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La Scala, Jr., N. [1] ; Lopes, A. [1] ; Spokas, K. [2] ; Archer, D. W. [3] ; Reicosky, D. C. [4]
Total Authors: 5
[1] Univ Estadual Paulista, FCAV, BR-14884900 Sao Paulo - Brazil
[2] USDA ARS, Soil & Water Management Unit, St Paul, MN 55108 - USA
[3] USDA ARS, No Great Plains Res Lab, Mandan, ND 58554 - USA
[4] USDA ARS, N Cent Soil Conservat Res Lab, Morris, MN 56267 - USA
Total Affiliations: 4
Document type: Journal article
Source: European Journal of Soil Science; v. 60, n. 2, p. 258-264, Apr. 2009.
Field of knowledge: Agronomical Sciences - Agronomy
Web of Science Citations: 16

To further understand the impact of tillage on carbon dioxide (CO2) emission, we compare the performance of two conceptual models that describe CO2 emission after tillage as a function of the non-tilled emission plus a correction resulting from the tillage disturbance. The models assume that C in the readily decomposable organic matter follows a first-order reaction kinetics equation as and that soil C-CO2 emission is proportional to the C decay rate in soil, where C soil ( t) is the available labile soil C (g m-2) at any time ( t) and k is the decay constant (time-1). Two possible relationships are derived between non-tilled (FNT) and tilled (FT) soil fluxes: (model 1) and (model 2), where t is time after tillage. The difference between these two models comes from an assumption related to the k factor of labile C in the tilled plot and its similarity to the k factor of labile C in the non-till plot. Statistical fit of experimental data to conceptual models showed good agreement between predicted and observed CO2 fluxes based on the index of agreement (d-index) and with model efficiency as large as 0.97. Comparisons reveal that model 2, where all C pools are assigned the same k factor, produces a better statistical fit than model 1. The advantage of this modeling approach is that temporal variability of tillage-induced emissions can be described by a simple analytical function that includes the non-tilled emission plus an exponential term, which is dependent upon tillage and environmental conditions. (AU)

FAPESP's process: 08/58187-0 - Impact of management practices on soil CO2 emission in sugarcane production areas, Southern Brazil
Grantee:Newton La Scala Júnior
Support type: Research Program on Global Climate Change - Thematic Grants