Nutrients from Effluent and Sludge Calculator

This calculator will help you target an appropriate application rate for your dairy farm effluent and/or sludge.

If you have sampled your effluent or sludge and have had a lab provide an analysis, you can now use the calculator to determine how much should be applied (both in mm and ML/ha).

Alternatively, if you haven’t sampled in recent years, you can adopt some published, typical nutrient concentrations. A caution before doing so – nutrient concentrations vary significantly from farm to farm because of differences in systems, management, and climate and it is always preferable to sample and use your own data.

The calculator will estimate how much N, P & K would be applied at the target application rate. And if you enter comparative local prices for a number of fertiliser products, it will also calculate the nutrient value of each ML of effluent or sludge spread.

Download the calculator here. You will require a PC running Excel version 2007 or later.