NPK Nutrient Input Calculations - Granular
To plan accurate granular turf fertiliser input it is important to know how much actual nutrient is being applied in any given treatment and over the course of a season.
This can be calculated in the following ways. Fertiliser analyses and inputs are expressed in elemental form for Nitrogen (N), but in oxide form (P2O5 and K2O) for phosphorus and potassium.
To calculate actual elemental input:
To calculate P2O5 to elemental P - Multiply by 0.44
To calculate K2O to elemental K - Multiply by 0.83
This can be useful when considering other constituents of fertilisers. For example, many granular fertilisers contain high levels of sulphur (S) expressed in the oxide form (SO3). To convert SO3 to elemental S - Multiply by 0.4.
To calculate the Kg of nutrient applied per hectare use: Application rate (in g/m2) x nutrient /10
An application of Multigreen 30.5.14 (6 to 7 month release) applied at 40 g/m2.
- 40 x 30 /10 = 120 Kg of N per hectare
- 40 x 5 /10 = 20 Kg of P2O5 per hectare
- 40 x 14 /10 = 156 Kg of K2O per hectare
Nutrient Input Calculator
Enter the product NPK figures and your intended application rate to calculate your NPK input in kg/Ha.