Dual-scale micro-CT assessment of soil structure in a long-term fertilization experiment

In this study we used X-ray microtomography (micro-CT) to evaluate the 3D pore size distribution and morphology of both undisturbed soil cores (5. cm diameter, 6. cm length) and aggregates (sieved at 5-6. mm). Samples were collected in a long-term fertilization experiment, established in 1962 in northeastern Italy, which considers organic (farmyard and liquid manure) and mineral treatments. The aim of the work was to assess the dual-scale effect of soil organic carbon (SOC) to influence the pore network in the range 6.25-2000. μm and to test the sensitivity of morphological features (connectivity, degree of anisotropy, fractal dimension) as indices of soil quality to management practices. Results on pore morphology suggested that connectivity was a sensitive index to differentiate the effects of management practices. Soil structure was multifractal and did not highlight any difference between treatments. Pore size distribution was affected by SOC as it increased the pores >. 560. μm of...