leach
verb [ T ] environment specialized uk/liːtʃ/ us/liːtʃ/
[ I or T ]漂洗，过滤（尤指土壤）
When a chemical substance leaches or is leached from a material, especially soil, it is removed by the action of water passing through the material.
The calcium, potassium, and magnesium ions are leached or washed out of the top soil into lower inaccessible subsoil. 钙、钾和镁离子被滤出表层土壤流入低层土壤却无法被吸收。
[ T ]（指土壤等）被漂洗，被过滤
When soil, etc. has been leached, it has had chemical substances removed from it.
The soil has been so heavily leached through intensive farming that it is no longer fertile. 过度耕作使养分大量流失导致土地贫瘠。