Soil Science deals with the understanding and modelling of the phenomena occurring in soils, mainly those related to the non-saturated zone. Since understanding most of those phenomena requires determination of parameters in scales allowing the incorporation of pore and aggregate variability to the models, a microscopic scale X-ray tomograph was built at Embrapa Agriculture Instrumentation. The aim was to generate non-destructive images of soil samples, within at least 100 ∝m spatial resolution. It was possible to design and construct a low cost equipment as compared to commercially available scanners, whose prices are prohibitive to soil studies. Tomographs of disturbed soils showing 212 to 250 ∝m aggregates were obtained. Pores with 100 μm size or less were observed. Pores with the same size could be detected in tomographs of samples containing 1 mm sand grains and capillaries with internal diameter of 100, 200 and 300 ∝m. Tomographs of undisturbed soil samples are also shown with pores ranging from 200 to 800 ∝m and high density particles.
tomography; microtomography; soil; X-ray; agriculture; porous media