Farmers in counties with the exception of Donegal, Leitrim, Cavan and Monaghan can now spread slurry following the closed period.

Teagasc has reminded farmers that weather and ground conditions have a significant impact on nutrients being lost to water.

Spreading slurry on fields that are frozen or snow covered, waterlogged, flooded or likely to flood is prohibited by the regulations.

Adding slurry to fields under these conditions, Noel Meehan of Teagasc added, increases the chance of nutrients from slurry being lost to water - either by overland flow in the case of saturated soils or by leaching to ground water.

Soil temperature

A consistent soil temperature of 6°C and preferably rising will mean that grass is growing and has the potential to take up the nutrients applied.

Another essential factor is the soil moisture content. Is the soil saturated or can tractor work occur without causing structural damage to the soil?

Soil that is close to or at saturation point will lead to surface water runoff if there is additional rainfall. Checking the soil moisture content of the field and the weather forecast is important prior to applying organic fertilisers, Meehan said.

Location

The fields where slurry is being spread should have a requirement for P and K and with a good pH, according to Meehan.

They should also be the drier fields on the farm, ideally with no drainage system in place and away from streams and rivers.

Rates

The rate of application is especially important in the early spring period where growth rates are at their lowest.

Applying slurry at rates greater than crop demand means that nutrient is available to be washed away into the drainage network or leached to groundwater. Lower application rates of organic fertilisers are recommended in early spring.