Morfologische onderzoekingen over de bodemstructuur

Various definitions of soil structure were reviewed and discussed. Soil structure was finally defined as 'the spatial arrangement of the elementary constituents and any aggregates thereof, and of the cavities occurring in the soil'.

The macrostructures, visible to the naked eye or with a lens not exceeding 4 x linear were divided into two large groups: those consisting of structural elements and those without these units.

A more detailed classification of the elements, formed by geological processes, was found necessary. Special attention was paid to the internal porosity of the elements and to the occurrence of various types of coatings and root prints.

The concept of grade of structure was discussed, and a scheme of description modified.

A classification of structures without structural elements was developed in which emphasis was placed on porosity.

Samples of higher sandy soils, underlying forest and heath, were described to demonstrate specific microstructures seen in thin sections.

Brown podsolic soils and podsols were shown to have characteristic differences in the morphology and mechanical behaviour of humus components.