Gilgai soil is a term used to describe soil that is characterized by mounds and depressions formed from the seasonal contracting and expanding of soil particles. There are several other synonyms for Gilgai soil depending on the geographical location and the local terminology. For example, in Australia, this type of soil is also known as "crabhole soil," "melon-holed soil," or "pippy grass soil." In the United States, some of the commonly used synonyms include "mima mound soil," "hogwallow soil," or "washboard soil." Regardless of the name, this type of soil can play a crucial role in agriculture, as the depressions can provide micro-environments for water storage and nutrient retention.