Get the balances right with your fertiliser usage
Step 5 – Make sure the fertilisers used are properly balanced
A balanced plant nutrient supply is very important during the growing season. It is especially important for productive ryegrass swards that soil reserves can supply sufficient nutrients to meet the peak demands at particular stages during the growing season.
Soil analysis plays a key role here as it gives a measure of the soil's ability to supply both major and minor nutrients. Fertiliser applications can then be tailored to supply the correct nutrient balance.
The type of fertiliser selected will depend on the soil nutrient status, the crop demands and the rate of organic manure application.
For example, the nutrient requirements for a grazed sward will be quite different to that of a grass silage sward.
A grazed sward will often require a fertiliser to deliver a P:K ratio of between a 1:2 to 1:4 and fertilisers such as 18-6-12 or 24-2.5-10 supply P:K within this range.
However, a silage sward will require a P:K ratio of 1:6 and fertilisers such as 15-3-20 or 10-5-25 supply P:K within this range.
Fertilisers with appropriate N-P-K ratios need to be used for these different grass crops to ensure the correct delivery of N, P and K to meet early and seasonal crop nutrient requirements to maximise grass growth.