Soils with high C.O.L.E. values can cave in basements, displace walls, and break gas or water pipes. Knowing which soils have high C.O.L.E. values is an important step in selecting sites for construction activities. Under field conditions, pore spaces are occupied at all times by air and water. Porosity, when expressed as a percent, is the same thing as percent pore space. Soil particles have irregular shapes, and thus the spaces or pores between them vary irregularly in size, shape and direction.
Sandy soils have large continuous pores, while clays have small pores which transmit water slowly.
Clays, however, contain more pore space than sandy soils, because of the pores inside of the soil peds. See the pore space and texture diagram. To growing plants, pore sizes are of more importance than total pore space. We will be discussing this more in the unit on soil water. In the laboratory you will determine porosity and particle density for the sandy soil used previously.