Description et analyse d'un modèle de respiration hétérotrophe appliqué à un sol agricole.

This work aimed to describe a mechanistic model for soil heterotrophic respiration, to apply it to an agricultural soil and to specify its important parameters, in order to define future research fields. A complete description of the model structure is given. It uses a daily time step and is derived from the CENTURY model. The model was found to be independent from the initial carbon pool contents and an exponential relationship was observed between the order of stabilisation of the different pools and their respective decomposition constants. Literature was scanned to provide a panel of biochemical parameter values (nitrogen, lignin, cellulose and hemicellulose contents) for wheat, sugar beet and potato crops. Large parameter ranges of values were noticed and a lack of information about sugar beet and potato crops drove our choice to work with wheat biochemical parameters later on. An exponential relationship between two parameters linked to the effect of temperature on microbial respiratory activity, respectively Tb and h, was highlighted. For a fixed value of Q10, the values of these two parameters varied in opposite ways. The sensitivity analysis was performed at both short and long terms, mainly on the basis of carbon pool contents. The results were very variable from one pool to another. In both analyses Tb and h appeared to be the most sensitive parameters while some differences between both time spans were noticed, notably because of pool stabilisation dynamics and crop residue types. In the end, the combination of sensitivity values with parameter ranges of values brought us to consider the parameters Tb, h, Nlit (% nitrogen in above-ground residues) and Lignlit (% lignin in above-ground residues) and the forcing variables MBR (root residues quantity) and Litfall (above-ground residues quantity) as the features about which further investigations would be needed. The integration of this mechanistic model into a more complete one, also taking account of autotrophic respiration and CO2 diffusion in soils, is a further goal to achieve.

Grantor dc:publisher

ULiège. GxABT - Liège Université. Gembloux Agro-Bio Tech

Year dc:date

2008

Author dc:creator

• Buysse, Pauline

Contributors dc:contributor

• Aubinet, Marc

• heterotrophic respiration
• agricultural soil
• Century model
• respiration hétérotrophe
• sol agricole
• modèle Century
• Life sciences
• Environmental sciences & ecology
• Sciences du vivant
• Sciences de l’environnement & écologie

Statement dc:rights

• open access
• info:eu-repo/semantics/openAccess

Licence

• http://purl.org/coar/access_right/c_abf2

Language dc:language

fr

Identifier

info:hdl:2268/56717

OAI identifier oai:identifier

oai:orbi.ulg.ac.be:2268/56717