Brossard Michel auteur aut IRD Fregonezi G.A.D. auteur aut IRD Guimaraes M.D. auteur aut IRD Medina C.D. auteur aut IRD Pasini A. auteur aut IRD Vilela L. auteur aut IRD Ayarza M.A. auteur aut IRD text journalArticle eng text/pdf reformatted digital access Ferralsols are characterized by poorly-defined horizons, weak macrostructure and strong development of a fine granular structure comprising subangular micro-aggregates. In this study, the morphological and physical modifications caused by earthworm activity in a clayey ferralsol were analysed. After describing soil structures, undisturbed samples were taken for evaluating aggregates and determining clod bulk density and particle density. Soil water retention properties were measured and an inventory of soil invertebrate macrofauna was created. The structural and porous transformations were due to aggregates created by earthworm activity. Changes in bulk density can be associated with pore modifications caused by a change in the proportions of aggregate types, and a notable reduction of total porosity was measured, tending to increase soil volume with dense aggregates. Structural modifications affected the topsoil down to 0.5 m and water retention between -1 and -33 kPa, the principal water compartment of these soils. specialized Oxisol Latossol Soil structure Aggregate Pore space Geophagous earthworm Cerrado Bioma BRESIL 068 344 1 41-49 2012 1631-0713 https://www.documentation.ird.fr/hor/fdi:010055669 10.1016/j.crte.2011.12.001 1631-0713 [F B010055669] https://www.documentation.ird.fr/hor/fdi:010055669 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers18-07/010055669.pdf IRD - Base Horizon / Pleins textes 2012-04-04 2018-08-09 fdi:010055669 fre