Translation guide
The layer of soil beneath the topsoil, often relevant in agriculture, construction, and geology. Japanese distinguishes between the natural subsoil layer and the act or process of deep cultivation that breaks it up.
Referring to the natural layer of earth below the surface soil, typically harder and less fertile.
Standard term for subsoil in agriculture and soil science. Refers to the layer beneath the topsoil (表土).
If the subsoil is hard, roots cannot grow deep.
Literally 'lower layer soil'. Used in geology, civil engineering, and soil classification.
The subsoil in this area is clayey.
Literally 'bottom soil'. Sometimes used in gardening or construction, but less technical.
The subsoil affects drainage.
Referring to the agricultural practice of breaking up compacted subsoil without inverting it, to improve drainage and root penetration.
心土 (しんど) is the subsoil, while 表土 (ひょうど) is the topsoil. In agriculture, 表土 is the fertile upper layer, and 心土 is the layer beneath it that may need breaking up.
The topsoil is fertile, but the subsoil is hard and compacted.
The katakana word サブソイル is not commonly used in Japanese. Stick with 心土 or 下層土 for natural expression.
This field needs deep plowing to soften the subsoil.