ABSTRACT
This chapter discusses the field test and soil description procedures that can be done visually or with simple field equipment. A number of soil physical parameters such as coarse fragments, mottled colors, pores, roots, lateral features, and mineral concentrations require area measurements on the ground surface or the wall of a pit for conversion to volume or weight percentages. Laboratory analysis is required for accurate determination of soil porosity, but field description of soil pores can provide useful qualitative data for estimating permeability and characterization of soil variability at a site. Soil texture, the relative proportions of silt-, sand-, and clay-sized particles is an important property from which many other soil parameters can be estimated or inferred. A restrictive layer is a nearly continuous layer that has one or more physical or chemical properties which significantly reduces soil water and air permeability or increases excavation difficulty.
