Nutrient composition of fertilisers


Nutrient composition of fertilisers

A wide range of fertilisers – and hence a wide range of nutrient compositions – is available. However, proprietary mixed products may not contain the correct ratio of nutrients for a particular crop type or growth stage.

Understanding the nutrient composition of various fertilisers helps in choosing the most appropriate for a given situation, saving money and time and preventing wastage.

A 'unit' of nutrient equals a kilogram of nutrient, but not a kilogram of fertiliser. The composition of a fertiliser is indicated on the container (bag) or packing slip as percentages or as N:P:K:S. Single superphosphate, for example, contains 0:8.8:0:11, meaning that a 100-kilogram bag would contain no nitrogen, 8.8 kilograms of phosphorus, no potassium and 11 kilograms of sulphur.

For further information refer to the vegetablesWA Good Practice Guide.