Quantifying physical and structural soil properties using X-ray microtomography

Abstract

One of the current challenges in the study of recovering soil architecture is physically evaluating the internal soil structure in unconventional ways. The elaboration of consistent methods and physical parameters has become necessary for soil structural analysis. The aim of this study is to analyze the soil structures of two groups of recovering tropical soils and to simulate three-dimensional water movement pathways using unconventional methods and physical soil parameters. The following results were obtained from the analysis: 1) the S index was used as an indicator to effectively quantify the degree of management; 2) Qualisolo software was used to obtain the soil water retention curve (SWRC) of each management type; 3) the degree of anisotropy of the solid structure reflected the soil network; 4) the Euler-Poincaré number reflected the connectivity of the soil pores for each management type; 5) the Shannon entropy indicated the degree of randomness of the soil; and 6) the results of the Arya and Paris model and the simulations of water movement pathways are similar. In conclusion, the obtained results reflect the internal soil structures and their corresponding characteristics. Thus, the results can be used to predict the influence of soil architecture on the movement of water in the soil.

X-ray Microtomography to Quantify Morphological Sandstones Properties

“…There were significant negative correlations between FD and DA, DA and SA and DA and Ma. For the sandstones studied, more complex pore structures are related to more homogeneous distribution (isotropic) of pores (FD × DA), which was expected considering Ma and NP results (Figures 2a and 2b) [33,34]. The same result was observed in terms of SA.…”

Hydrological trade-offs due to different land covers and land uses in the Brazilian Cerrado

“…This variation in the wooded Cerrado was less than 1 m yr −1 due to the water deficit periods during the dry season. In addition, a similar study in a Cerrado area (Villalobos-Vega et al, 2014) verified that the groundwater table fluctuation tend to be lower where the unsaturated zone is thicker. In the well located in the pasture, the water table fluctuated negatively in 2014 and 2015 due to the drought that happened in 2014 (Getirana, 2015).…”

“…Consequently, the water uptake by the plants became unfeasible, as the roots were more shallow (see Table 2) than in the wooded Cerrado. Furthermore, the aquifer recharge decreases as the vegetation density increases in undisturbed Cerrado areas , following the principle that the increased canopy cover of the wooded Cerrado found in the study area may occur due to the deep groundwater level (Leite et al, 2018;Villalobos-Vega et al, 2014). However, the water balance analysis performed here focused on hillslope hydrology, and the monitoring well depths reflect the aquifer behavior in a broader area covered by pasture and wooded Cerrado in comparison with the 100 m 2 plots where we monitored the surface water partitioning.…”

Hydrological trade-offs due to different land covers and land uses in the Brazilian Cerrado

“…Consequently, the water uptake by the plants became unfeasible, as the roots were more shallow (see Table 2) than in the wooded Cerrado. Furthermore, the aquifer recharge decreases as the vegetation density increases in undisturbed Cerrado areas (Oliveira et al, 2017), following the principle that the increased canopy cover of the wooded Cerrado found in the study area may occur due to the deep groundwater level (Leite et al, 2018;Villalobos-Vega et al, 2014). However, the water balance analysis performed here focused on hillslope hydrology, and the monitoring well depths reflect the aquifer behavior in a broader area covered by pasture and wooded Cerrado in comparison with the 100 m 2 plots where we monitored the surface water partitioning.…”