Vauclin Michel, Chopart Jean-Louis.
1992. Field determination of surface hydraulic properties of a tilled and untilled gravelly soil.
In : Operational methods to characterize soil behavior in space and time = [Méthodes opérationnelles de caractérisation du comportement du sol dans l'espace et dans le temps]. ISSS
Autre titre : Détermination au champ des propriétés hydrauliques de surface d'un sol graveleux travaillé ou non travaillé
Résumé : Suction disk infiltrometers of dissimilar radii are used at different unsaturated supply-potential heads to determine surface hydraulic properties of a gravelly ferralitic soil managed according to three different agricultural practices : direct sowing of both corn and cotton, ploughing before each crop, and recent ploughing of a fallow. It is shown that this very simple and easy technique leads to the knowledge of two phenomenological parameters describing soil infiltration, namely hydraulic conductivity and capillary sorptivity. Their interpretation allows inferences to be made about other physical parameters providing explanation of contrasting hydrologic behaviour of the three treatments. The results clearly show positive but temporarily impact of ploughing upon soil infiltrability (increase of both conductivity and mainly sorptivity) and upon ponding time. In addition, they allow to suggest a scheme able to explain time evolution of the hydro-physical behaviour of the surface layer in connection with the tilled and untilled soil treatments and the development of a network of macropores. This latter leads to preferential flow patterns casting doubt upon the classical ponding so-called Muntz method to provide reliable results for soil infiltrability. It also appears that sorptivity, not conductivity will be the most infiltration into this soil. For such conditions it is demonstrated that 3D flow imposed by the disk geometry works in our favour to induce a steady flow long (about 45 minutes) before gravity effect intercedes (several days) as it will happen for classical 1D vertical infiltration tests.
Mots-clés Agrovoc : sol caillouteux, propriété hydraulique du sol, expérimentation au champ, mesure (activité), méthode, non-travail du sol, labour
Classification Agris : P33 - Chimie et physique du sol
U30 - Méthodes de recherche
Auteurs et affiliations
- Vauclin Michel
- Chopart Jean-Louis
Autres liens de la publication
Source : Cirad - Agritrop (https://agritrop.cirad.fr/400917/)
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