The majority of Green-Keepers and Groundsmen are keen to monitor exactly how much NPK nutrient they are actually feeding their grass when applying fertilisers. Calculations to ascertain these input figures are detailed below.

 

Granular fertiliser:

In order to calculate the total kg application of nutrient/ha. take the application rate in g/m² X the % of nutrient content ÷ 10.

Example:

An application of Amtech 12-3-9 + Fe + Te 25% Nutralene @ 30g/m²

 

30 X 12 ÷ 10 = 36kg Nitrogen (N)/ha.

30 X 3 ÷ 10 = 9kg Phosphate (P)/ha.

30 X 9 ÷ 10 = 26kg Potassium (K).ha.

 

Soluble fertilisers:

In order to calculate the total kg application of nutrient/ha. take the application rate in kg/ha. X the % of nutrient content ÷ 100.

Example:

An application of Fertech KN 12-0-44 @ 20kg/ha.

20 X 12 ÷ 100 = 2.4kg Nitrogen (N)/ha.

20 X 44 ÷ 100 = 8.8kg Potassium (K)/ha.

 

Liquid fertilisers:

The Amtech liquid range is labelled as W/V which enables the use of the same calculation as soluble fertilisers.

Example: An application of Amtech liquid 16-3-10 @ 50L/ha.

50 X 16 ÷ 100 = 8.0kg Nitrogen (N)/ha.

50 X 3 ÷ 100 = 1.5kg Phosphate (P)/ha.

50 X 10 ÷ 100 = 5kg Potassium (K)/ha.