OverseerFM caters for different effluent types by assuming that inorganic N in organic material (effluents, composts, etc.) behaves similarly to fertiliser N and that the organic N component is slowly released over several months, depending on the N content of the material.
Fertiliser and N supplied by effluent (inorganic and slow released from inorganic) are then included in the crop N model or the background pasture model. The interactions between various sources of N (soil, fertiliser, effluent, irrigation, etc) and losses (uptake, denitrification, leaching) are included in the estimation of N leaching.