Thread by @WardHydro

New research dropped from @MollyRCain on #water & #nitrogen dynamics in agricultural systems.

Multiple, interacting thresholds control water, N losses in tile drained landscapes

@pkumar3691 @IMLCZO #CriticalZone #CZO @IUONeillSchool @IUImpact
doi.org/10.1029/2021WR…

@MollyRCain @pkumar3691 @IMLCZO @IUONeillSchool @IUImpact FAVORITE FIGURE IN THE PAPER:
Interacting 'top down' (antecedent soil moisture) and 'bottom up' (GW level) control the sources, ages, and N loads in water mobilized from tile-drained landscapes.

@MollyRCain @pkumar3691 @IMLCZO @IUONeillSchool @IUImpact What controls C-Q dynamics in tile drains? Event size and antecedent conditions (in this case, if the groundwater table was high enough to have the tile flowing with pre-event water when the storm hit)

One more. Event runoff (Y-axis) is a function of
precip,
ASI (the soil moisture that must be 'filled' to activate runoff generation from the soil column), &
groundwater deficit (the height the groundwater table must be raised to activate tile drainage of groundwater).

For systems we engineered, tile drained hillslopes are way more complex that we expected.

Which water comes out of tile drains? A mix of event water (macropore flow), pre-event soil water (displaced by event water), and groundwater (activates as regional water table rises).