With restrictions on applying slurry and fertiliser now lifted, it is worthwhile getting soils tested before heading out with the first application of nitrogen (N).

Soil testing will indicate if soils are low in phosphate (P) or potash (K), as well as indicating if soils need lime if pH levels are too low.

Correct index

Grazing and silage fields should ideally be at index 2 to index 3 for P and K to get the best possible grass growth.

Slurry and a combination of straight N and compound fertilisers will maintain fertility levels in these fields.

Acidic soil reduces the amount of fertiliser available and locks up nutrients in soils

For fields that are low in P and K, then compound fertilisers will be required to build fertility levels, as straight N products will limit growth.

Acidic soil reduces the amount of fertiliser available and locks up nutrients in soils.

For grassland, grass growth is maximised when soil pH levels are at 6.0 to 6.5.

Top tips for soil sampling this spring

When to sample

Only sample fields that have not received any fertiliser, or been grazed, for at least 10 to 12 weeks prior to taking samples to get an accurate.

For the majority of Irish farms, early February is generally a good time to get soils tested, before the rush to get slurry and fertiliser applied, to kick-start grass growth as ground conditions improve.

Target less-productive fields

Select fields that have poor growth every year. If a soil test shows the field is fine for lime, P and K, you need to check for soil compaction, drainage problems or sward quality. The field may just need reseeding due to low levels of perennial ryegrass in the sward.

Take a representative sample

Soil types can vary within a field, so the more cores you take the better. Take at least 20 cores per field, walking in a zig-zag direction and put all cores in a bucket and mix. From this combined sample, fill a sample bag and submit for testing.

You only need to take a sample from the top 4in to 6in of soil using a soil corer, or simply use a spade. You will need no more than a handful of soil from each sample point.

Areas to avoid

Avoid taking a core sample where ring feeders or meal troughs have been placed, as you will get a false reading from your soil samples. Cattle will pass greater quantities of dung and urine in these areas.

For the same reason, avoid sampling areas close to dung pats. Avoid the area around water troughs, field headlands and boundaries also.

Limit sample areas to 10 acres max

Ideally, one sample should be taken from each field, but this is not always practical.

Smaller grazing fields of 1 acre to 2 acres can be grouped together as one sample, if they usually get the same fertiliser applied.

Limit the sample area to a maximum of 10 acres. For fields over 10 acres in size, you should take two or more samples.

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