subsoil
n. 底土，下层土
v. 深挖，深耕；掘起……的底土
例句
Rock fragments from the subsoil can end up concentrated on the surface.
来自底土的岩石碎片最终可能集中在地表。
Nitrate and water-soluble organic nitrogen were migrated with deionised water migrating and increased subsoil fertility.
硝酸盐和水溶性有机氮随着去离子水的迁移而迁移，并增加了土壤的肥力。
He embedded the pilings deep into the subsoil.
他把桩深深打进地基下的土中。
