Leaching Fraction and Runoff Conductivity
Computes the leaching fraction and the no-uptake upper bound on leachate conductivity.
Example
You enter
- Volume applied per event 1
- Volume collected as leachate 0.2
- Feed solution EC (mS/cm) 2
- Measured leachate EC (mS/cm) 3
- Alternative leaching fraction 0.4
- Target leachate EC (mS/cm) 3
You get
- Leaching fraction 0.2
- Leaching fraction 20.0%
- No-uptake upper bound 10
- At the alternative leaching fraction 5
- Implied crop uptake 70
- To hold the target on the bound alone 66.6667
Details, formula, and sources
Computes the leaching fraction and the no-uptake upper bound on leachate conductivity, then derives the crop's salt uptake from the gap to a measurement. The bound is never a target: holding 3.0 mS/cm on it alone would take a 67% leaching fraction nobody irrigates at.
leaching fraction = volume drained / volume applied; the no-uptake upper bound on leachate conductivity = feed EC / leaching fraction; implied uptake is the gap between that bound and a measurement.
A pour-through or saturated-media extract done consistently, and the crop's own published root-zone EC range, govern.
Public arithmetic; root-zone EC ranges are published by extension services.
Estimate. AHJ and licensed professional govern.
Field names used by the API: volume_applied, volume_drained, feed_ec, measured_leachate_ec, alternative_leaching_fraction, target_leachate_ec, leaching_fraction, leaching_fraction_pct, bound_ec, alternative_bound_ec, implied_uptake_pct, required_leaching_fraction_pct
- Steady state a single event is modelled; accumulated salt from prior events is not carriedspec-v1762 scope
- Procedure pour-through and saturated-media extract give different numbers; consistency matters more than whichextension guidance