The implications of lag times between nitrate leaching losses and riverine loads for water quality policy.

ABSTRACT: Understanding the lag time between land management and impacts on riverine nitrate-nitrogen (N) loads is critical to understand when action to mitigate nitrate-N leaching losses from the soil profile may start improving water quality. These lags occur due to leaching of nitrate-N through the subsurface (soil and groundwater). Actions to mitigate nitrate-N losses have been mandated in New Zealand policy to start showing improvements in water quality within five years. We estimated annual rates of nitrate-N leaching and annual nitrate-N loads for 77 river catchments from 1990 to 2018. Lag times between these losses and riverine loads were determined for 34 catchments but could not be determined in other catchments because they exhibited little change in nitrate-N leaching losses or loads. La

SUBMITTER: McDowell RW 

PROVIDER: S-EPMC8360963 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature