There are small differences in the way irrigation, and dairy factory effluents are modelled.
First, the N in irrigation is treated as inorganic N whereas dairy factory effluent contains organic N as well as inorganic.
These differences can affect background N leaching, and pasture N concentrations, hence N intake, excreta deposition, and urine N leaching. There are also small differences in the way water is added resulting in slightly different drainage.
Where dairy factory waste is being applied to a farm, this split between organic and inorganic N forms should be considered.
If organic N is present (which it usually will be), the waste water should be entered as a Dairy factory : custom nutrients application: