Measuring Physical Properties of Soil

A variety of soil physical measurements can be used to evaluate the effectiveness of soil conditioners. These measurements include infiltration rate, air permeability, porosity, aggregate stability, penetration resistance, or bulk density. Reliable standardized procedures are needed to compare and/or evaluate the effect of soil conditioners on soil physical properties. For example, many companies rely on penetrometer measurements to evaluate their product, but do not standardize their measurements with respect to moisture content or bulk density. Such non-standardized observations may easily lead to erroneous claims about the product. Also, be cautious of studies relying on measurements that are not easily quantified such as soil tilth, stickiness, tightness, or hardness. 

Porosity Porosity is a measure of the fraction of the volume of voids over the total volume in a material. 

Permeability A measure of the ability of a material to transmit fluids. 

Bulk density It is defined as the mass of many particles of the material divided by the total volume they occupy. 

Infiltration rate Infiltration rate in soil science is a measure of the rate at which soil is able to absorb rainfall or irrigation. 

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