Characterisation of pore space in soil
The pore space of soil contains the liquid and gas phases of soil, i.e., everything but the solid phase that contains mainly minerals of varying sizes as well as organic compounds.
In order to understand porosity better a series of equations have been used to express the quantitative interactions between the three phases of soil.
Macropores or fractures play a major role in infiltration rates in many soils as well as preferential flow patterns, hydraulic conductivity and evapotranspiration. Cracks are also very influential in gas exchange, influencing respiration within soils. Modeling cracks therefore helps understand how these processes work and what the effects of changes in soil cracking such as compaction, can have on these processes.
The bulk density of soil depends greatly on the mineral make up of soil and the degree of compaction. The density of quartz is around 2.65 g/cm3 but the bulk density of a soil may be less than half that density.
Most soils have a bulk density between 1.0 and 1.6 g/cm3 but organic soil and some friable clay may have a bulk density well below 1 g/cm3
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