In the Oracle Bone Script, it depicts a pile of soil on the ground. Its original meaning is soil. 土 is also a Chinese radical. Chinese characters with the radical 土 have meanings related to land, earth or soil, such as: Dì-地-earth, Chǎng-场-courtyard, Jī-基-base, Tián-填-to fill in.
土是象形字。甲骨文的字形像地面上的一堆土。这个字的本义是土壤。 土也是一个汉字的偏旁部首，土字旁的字通常与土地有关，比如：地、场、基、填。
Link: Chinese characters with the radical 土 (Tǔ)
