~ ~ ~ PURPOSE ~ ~ ~ this subroutine calculates degradation of pesticide in the soil and on the plants
~ ~ ~ INCOMING VARIABLES ~ ~ ~ name |units |definition ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ decay_f(:) |none |exponential of the rate constant for |degradation of the pesticide on foliage decay_s(:) |none |exponential of the rate constant for |degradation of the pesticide in soil ihru |none |HRU number
calculate degradation in soil add decay to daughter pesticides calculate degradation on plant foliage adjust foliar pesticide for wash off add decay to daughter pesticides