Quantification of soil macroporosity and its relationship with soil properties.

摘要

Image analysis was used to estimate macroporosity (pores >= 0.54 mm in diameter) of undisturbed soil columns obtained from a field under no-tillage for 5 years in Ontario (Luvisol). A high resolution X-ray Image Intensifier (XRII)-based CT scanner was used to investigate soil macroporosity at different depths in the soil column. Total macroporosity in the A and B horizons averaged 3.70 and 1.94%, respectively, and was consistently lower in the B horizon. The relative contributions of macroporosity to the total porosity in the A and B horizons were 7.76 and 4.92%, respectively. There was a statistically significant decreasing trend of macroporosity through the combined A and B horizon depth (0-400 mm) and in the A horizon (depth 0-200 mm), but not in the B horizon (depth 200-400 mm). Saturated hydraulic conductivity correlated significantly with the total macroporosity of the A and the B horizons. Within the A horizon, bulk density also significantly correlated with total macroporosity.