Publications des scientifiques de l'IRD

Bottinelli Nicolas, Zhou H., Boivin P., Zhang Z. B., Jouquet Pascal, Hartmann Christian, Peng X. (2016). Macropores generated during shrinkage in two paddy soils using X-ray micro-computed tomography. Geoderma, 265, p. 78-86. ISSN 0016-7061.

Titre du document
Macropores generated during shrinkage in two paddy soils using X-ray micro-computed tomography
Année de publication
2016
Type de document
Article référencé dans le Web of Science WOS:000368746200009
Auteurs
Bottinelli Nicolas, Zhou H., Boivin P., Zhang Z. B., Jouquet Pascal, Hartmann Christian, Peng X.
Source
Geoderma, 2016, 265, p. 78-86 ISSN 0016-7061
Soil shrinkage curve represents a decrease of total porosity or an increase of bulk density with water loss. However, our knowledge of the dynamics of pores and their geometry during soil shrinkage is scarce, partially due to lack of reliable methods for determining soil pores in relation to change in soil water. This study aimed to investigate the dynamics of macropores (>30 mu m) of paddy soils during shrinkage. Two, paddy soils, which were sampled from one paddy field cultivated for 20 years (YPF) and the other one for over 100 years (OPF), represented difference in crack geometry in the field. Macropore parameters (volume, connectivity, and orientation of pores) and soil shrinkage parameters were determined on the same undisturbed soil cores by X-ray microtomography and shrinkage curve, respectively. Macroporosity was on average four times larger in the YPF than in the OPF whereas the shrinkage capacity was lower in the YPF as compared to the OPF (0.09 vs. 0.15 COLE). Soil shrinkage increased the volume of pores by 3.7% in the YPF and by 1.6% in the OPF as well as their connectivity. The formation of macropores occurred mostly in the proportional shrinkage phase. As a result, the slope of the proportional shrinkage phase was smaller in the YPF (0.65) than in the OPF (0.89). New macropores were cracks and extended pre-existing pores in the range of 225-1215 pm size without any preferential orientation. This work provides image evidences that in paddy soils with high shrinkage capacity more macropores are generated in the soil presenting a smaller proportional shrinkage slope.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Pédologie [068]
Description Géographique
CHINE
Localisation
Fonds IRD [F B010066157]
Identifiant IRD
fdi:010066157
Contact