Over the coming days and weeks, fertiliser programmes will be starting on many intensive grassland farms.

The exact timing will depend on a number of factors such as location, soil conditions and temperatures.

However, when conditions are right, it is important to be ready to spread.

With that, we take a look at what type of fertiliser you should be spreading and how much of it you need to order this spring.

Type

Urea, at 46% nitrogen (N) (€0.75/kg N), is a cheaper source of N compared with CAN at 27% N (€1.00/kg N).

However, urea must be used in optimum conditions to make the most of this price differential.

Urea works best in low temperature conditions and when rainfall is present (<15mm), meaning it is ideal for spring applications.

But thinking slightly further down the line, where straight N is applied in the first application, consider 18:6:12, (18% N) or 10:10:20 (10% N) to supply phosphorus (P) and potassium (K) in the second round of fertiliser applications four to six weeks later.

The N quantities of each fertiliser type are important to remember as we move on to quantities.

Quantity

Table 1 give a breakdown of the recommended quantities (kg/ha) of N that should be spread in the first three applications of the year, based on the farm's stocking rate (kg/ha organic N).

Notice that the recommended application rates are given both as kg/ha N or as units/acre – farmers vary between preferred calculation methods.

To convert the stocking rate given in kg/ha of organic N into animals per hectare, use the figures provided in Table 2.

For example, two suckler cows and two calves per hectare would give a stocking rate of 178kg/ha organic N (2.6LU/ha).

Summary

Briefly summarising Table 1, moderately stocked farms (2 to 2.5 LU/ha), should be spreading 23 N units/acre (28kg/ha N) in the first application.

This will more than likely be urea and will thus equate to half a bag per acre (61kg/ha).

In the second rotation, at some stage in March, most farms will be putting out between 35 and 40 N units/acre (43 to 49kg/ha N).

This will equate to approximately three-quarters of a bag per acre (91kg/ha) of urea or, alternatively, if a compound is used (for example 18:6:12), application will be 2.2 bags per acre (271kg/ha).

It is working off this basis that you can easily work out your total spring requirement.

Start off with how much will be applied per acre and multiply by the area that needs to be covered.