soil moisture; soil water
Technical term used in agriculture, environmental science, and engineering to refer to the water content in soil.
We measured the soil moisture level in the field with a soil moisture sensor.
When drought continues, soil moisture becomes insufficient and affects crop growth.
水分 means moisture or water content in general, while 土壌水分 specifically refers to moisture in soil.
土壌 means soil as a medium; 土壌水分 is the moisture within that soil.
Compound of 土壌 (soil) and 水分 (moisture). The exact historical derivation is straightforward; the term is a modern technical compound.