As to whether effluent is a waste or a benefit, depends entirely on how you, the farmer, use it.
A supply of nutrients and minerals to soils which is greater than the amount needed to maintain soil health and fertility actually endangers the soil and can negatively impact on surface and ground water sources.
Many nutrients are wasted on dairy farms due to oversupply through inputs from fertilizers and feeds. A great deal of nutrients, and therefore money, can be saved by recording and monitoring what nutrients are removed from the farm and what nutrients are brought onto the farm.
Two of the prominent aspects of sustainability are long-term profitability and environmental protection. Limiting chemical nitrogen fertiliser use to only what is very necessary contributes to both of these aspects.
Excessive use of chemical nitrogen fertiliser has a negative effect on soil life and soil structure. Yet there still seems to be a trend of farmers wanting, or feeling the need, to apply excessive chemical nitrogen fertiliser to pastures.
Here is an example of how improved soil life and good soil structure can unlock unavailable nitrogen into a form that is readily available for pasture uptake. You can possibly reduce your nitrogen fertiliser costs.