SOIL SHRINKAGE CURVES AND MICROMORPHOLOGY IN CONTRASTING MANAGEMENTS

FERNÁNDEZ, P., ÁLVAREZ, C., BEHRENDS, F., MORRÁS, H., SCHEINER, J., BOIVIN, P., TABOADA, M.

Ciencia del Suelo

ASOCIACIÓN ARGENTINA DE LA CIENCIA DEL SUELO

Lugar: Buenos Aires; Año: 2020 vol. 38 p. 1 - 16

0326-3169

Compaction processes are generally described using methods that do not distinguish volume changes of differenttypes and pore sizes. The adjustment of shrinkage curves (ShC) using the XP model allows elucidation ofthe effects of soil management on changes in pore volume. This method coupled with micromorphological andmicromorphometric determinations in soil thin sections allows the characterization and quantification of importantsoil features included pore types. The aim of this work was to examine the potential of shrinkage analysis todescribe soil physical degradation under the most common management (continuous cropping-CC), an alternativemanagement (integrated crop/livestock-ICL), related to quasi-pristine (QP); in two soils of northern of the Pampeanregion of Argentina (Typic Hapludoll and Typic Argiudoll). We focused on the changes of soil structural porosityin both methods (ShC and micromorphological analyses) in silty soils with low shrinkage-swelling capacity. TheQP had a higher volume (or lower bulk density) in both soils. The slope of the structural phase was QP50 μm = QP(20.0%)>ICL(17.7%)>CC(16.0%)). CC and ICL were characterized bythe development of platy peds and horizontally oriented planes, whereas ICL presented more biological activity.ShC and micromorphology analyses improved the understanding of soil functioning in these non-expansive soils,allowing the comparison between cattle trampling and continuous cropping in different soil types.