Characterization of the major cambisols in North Central Portugal

• Main Author: Pereira, Virginia Maria Fatal Gomes
• Published: University of Aberdeen 1984
• Subjects: 551; Soils
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234461

This study provides information about six representative Cambisols in North Central Portugal. The study area is part of the drainage basin of the river Vouga, where Cambisols are most extensive. Their general characterization includes the estimation of pH, loss-on-ignition, organic carbon, total nitrogen, cation exchange capacity, exchangeable cations and percent base saturation, particle-size analysis, "free" Fe, Si and Al, mineralogy of the clay fraction, heavy mineralogy of the fine sand fraction and micromorphology. These preliminary investigations revealed some distinctive features in these soils on which particular attention was focussed, namely their polycyclic character, the unique characteristics of the upper horizons and the presence of gibbsite. Finally, UV autofluorescence was observed in weathering products of aluminosilicates, which were identified as gibbsite by electron-probe microanalysis and scanning electron microscopy and compared to standard minerals. The potential of this technique in soil micromorphological studies was assessed.