Deep groundwater in the Kumamoto area affected by nitrate nitrogen with source origin by sterols
Nitrate nitrogen contamination of groundwater is often related to agricultural production and is a common problem in many parts of the world, particularly in regions that depend on groundwater for water supply. Nitrate nitrogen concentrations in groundwater in the Kumamoto area have increased in recent years, and countermeasures are urgently needed. Identifying the causes and sources of contaminat
