The Measurement and Characterisation of Voids in Soil Thin Sections by Image Analysis. Part Ii. Applications

Abstract

WITH TWO PLATES SummaryImage analysis was used to measure and characterise the voids in two sets of soil samples; (i) a surface water gley soil of the Deighton series and (ii) soils from a compaction experiment. The results show that the Deighton soil contains two impervious horizons separated by a much more porous horizon. In all the horizons most of the pore space is due to pores >180 pm diam. In the case of the soils from the compaction experiment compaction was shown to change the shape, orientation and size distribution of the pores considerably. The range of measurements demonstrates that image analysis is applicable to several areas of soil research.

Micromorphology and image analysis of a hardsetting Ultisol (Argissolo) in the state of Ceará (Brazil)

“…, where the numerator is the larger value (Murphy et al, 1977). Orientation was calculated only for elongate pores.…”

“…5d) horizons ( P N 0.10). Based on this information, and given that the elongate pores are influenced by natural soil compaction (Murphy et al, 1977), this pore type has been used to establish preferential orientation in the less dense areas and more dense areas of the hardsetting (Fig. 6a,c) and non-hardsetting (Fig.…”

“…This technique allows a quantitative evaluation of soil features that are usually established in the field using the naked eye (Murphy et al, 1977;Protz et al, 1987). The use of image analysis techniques may help to better understand the particular behavior exhibit by hardsetting horizons during the process of drying and wetting.…”

Software for micromorphometric characterization of soil pores obtained from 2-D image analysis

“…The first refers to the image void space (assumed to be pores) and includes the area, number of objects, and for each object, its perimeter, horizontal and vertical Feret diameters, as well as its horizontal and vertical projections. The derived variables are a combination of two or more basic variables which allow for a complete characterization of the soil pores (Murphy et al, 1977a). These variables are then used to classify the void spaces, according to a combination of shapes and sizes.…”

“…In the literature, there are studies addressing soil compaction (Murphy et al, 1977a;Curmi et al, 1994;Clemente et al, 2005;Bagheri et al, 2012), cultivation and management systems (Pagliai et al,1983;Pagliai et al, 1984;Pagliai et al, 2003;Soares et al, 2005;Juhász et al, 2007;Rasa et al, 2012), effect of wetting and drying cycles on the structure of tropical soil (Pires et al, 2008), soil structure regeneration with and without selfmulching Collis-George, 1990a and1990b), application of fertilizers, manures, and organic materials (Pulleman et al, 2005;Zanuzzi et al, 2009), surface crusting (Castilho et al, 2015) and soil fauna activity (Castellanos-Navarrete et al, 2012;Piron et al, 2012).…”