Dairy effluent is rich in critical nutrients, including nitrogen (N), phosphorus (P), and potassium (K). However, because nutrient concentrations can vary significantly between farms, an effluent test is strongly recommended as the best method to determine the precise and most appropriate application rate. Applying the correct amount is vital, as excessive application increases the risk of negative outcomes such as nitrate poisoning, mineral imbalances in grazing cattle, and detrimental environmental losses.

Farmers must adhere to strict guidelines on application rates to ensure both safety and efficacy. For liquid effluent, the maximum recommended application should be no more than 60-80 kg of nitrogen per hectare per application. For potassium, the total applied should not exceed 60 kg per hectare per application, with an annual limit of 120 kg per hectare. If a chemical analysis is unavailable, a practical rule of thumb for liquid effluent is to apply 1 megalitre per 4 hectares to targeted, low-nutrient areas where the risk of runoff is eliminated.

A critical component of this strategy is the mandatory 21-day withholding period for grazing after liquid effluent application. This restriction is necessary to prevent significant issues like palatability or fouling of the pasture, and to mitigate the risk of pathogen transmission to the grazing herd. This waiting time also provides sufficient duration for the plants to fully respond to the applied nutrients, maximizing the agronomic benefits for the farmer.