The effect of wetting and drying cycles on soil chemical composition and their impact on bulk density evaluation: An analysis by using XCOM data and gamma-ray computed tomography (original) (raw)

The soil elemental (oxides) composition variation of three Brazilian soils submitted to the application of wetting and drying (W-D) cycles was measured in order to evaluate the possible changes in the calculated soil mass attenuation coefficient (μ) as a function of the cycles. Measurements of μ by using radioactive sources of 241 Am and 137 Cs were also performed. Gamma-ray computed tomography (CT) was used as a tool to evaluate the impact of changes in μ induced by the cycles in determinations of soil bulk density (d s). The measured and calculated values of μ presented good agreement. Significant modifications were not observed in the total elemental composition of the soils after the application of W-D cycles. As a consequence only slight changes in μ were observed. However, the use of CT allowed concluding that even small changes in μ can cause some change in d s .