"Clay soil" refers to a type of soil that is made up of very fine particles that stick together. It is sticky and hard when wet, but becomes very hard and compact when it dries. Full definition
In the case of eating soil, this is particularly evident in breeds which have known natural iron deficiencies, and this demonstrates how they may be seeking extra dietary iron in clay soils. (petpeoplesplace.com)
The red clay soil is used widely in prayer ceremonies and used as offerings. (greatrail.com)
«Significant relationships were found and the accuracy of root detection was higher in wet clay soils than in dry sandy soils,» he said. (today.agrilife.org)