Modelling long term carbon dynamics in soil reconstituted with high quantities of organic matter

Abstract : In urban conditions, the widescale availability of organic matter to be recycled and the necessity for soil reconstitution (Technosol) has led to the input of very large quantities of organic matter (up to 50% v/v). The long-term degradation of these large quantities of organic matter in the soil is not well known. We monitored, over a 60-month period, the total carbon (C) content and the particulate and biochemical fractions of reconstituted soils placed in 600-litre boxes under natural conditions. The top layer was a sandy loam amended with 20 or 40% of sphagnum peat or organic compost (sewage sludge, wood chip compost or green waste compost) lying on a layer of sandy loam. We measured C mineralization over time under controlled conditions and built a long-term model to simulate carbon dynamics where exogenous organic carbon (EOC) was divided into two biodegradable compartments. The model yielded the proportions of EOC that either resisted degradation or contributed to soil organic C storage by mineralization and/or humification. Organic matter degradation was linked to its maturity and to its contents in certain particulate and biochemical fractions but was independent of how much of a given organic matter was introduced. We found a good correlation between the degradable organic compartment and the lignin and cutin-like, hemicellulose and cellulose-like fractions larger than 1 mm. The model showed that a large part of initial EOC was still present in the soil after 5 years in a potentially biodegradable but resistant compartment. The degradation of that compartment by mineralization or humification is therefore expected to take longer.
Type de document :
Article dans une revue
European Journal of Soil Science, Wiley, 2012, 63, pp.787-797. 〈10.1111/j.1365-2389.2012.01494.x〉
Liste complète des métadonnées

https://hal-agrocampus-ouest.archives-ouvertes.fr/hal-00917864
Contributeur : Catherine Cliquet <>
Soumis le : jeudi 12 décembre 2013 - 15:43:55
Dernière modification le : jeudi 14 décembre 2017 - 14:04:01

Identifiants

Citation

Laure Vidal Beaudet, C. Grosbellet, Virginie Caubel, Sylvain Charpentier. Modelling long term carbon dynamics in soil reconstituted with high quantities of organic matter. European Journal of Soil Science, Wiley, 2012, 63, pp.787-797. 〈10.1111/j.1365-2389.2012.01494.x〉. 〈hal-00917864〉

Partager

Métriques

Consultations de la notice

107