(E_H) the potential that is generated between an oxidation or reduction half-reaction and the standard hydrogen electrode (0.0v at pH = 0) —note in soils it is the potential created by oxidation-reduction reactions that take place on the surface of a platinum electrode measured against a reference electrode minus the E_H of the reference electrode; this is a measure of the oxidation-reduction potential of electrode reactive components in the soil —see plinthite, soil reactionThis definition last updated 12/09/2008