Can I grow more grass by spreading water on my paddocks?

Ireland is currently gripped by a drought that is seriously affecting most farming enterprises. Many livestock farmers have started to feed grass silage and alternative feeds in order to stretch rotations.

Soil moisture deficits are extremely high, with many places not witnessing rainfall for a number of weeks. Due to these conditions, many farmers may have asked the question: “Would irrigating my paddocks encourage grass growth?”

Speaking at a recent fodder event – organised by Teagasc – on John and Shirley Watchorn’s farm in Co. Wexford, Teagasc’s Fergus Bogue answered this question.

“Our soil moisture deficit at the moment is 3-4in of rain. 27,000 gallons of water per acre would be the same as 1in of rain,” he said.

“Therefore, it would be very expensive. Getting out 27,000 gallons of water per acre would only be scratching the surface of the problem.

“Spreading this amount of water will not rectify the situation; evaporation will also happen everyday. Therefore, you might not even get the full value of the inch of water; it is not practical and too expensive,” he added.

Soil moisture deficits

Yesterday (July 10), the Status Yellow weather advisory warning for Ireland – which has been in place since Saturday, June 30 – was extended until later this week by the Met Eireann.

The warning will remain in place until 12:00pm on Friday, July 13. A further review of the situation will take place as the current warning expires.

It is expected that there may be some alleviation in drought conditions in places this week.

However, there will be little initial reduction in soil moisture deficits as evapotranspiration rates (the loss of water from the soil both by evaporation and by transpiration from plants) will remain high, Met Eireann added.

At the moment, soil moisture deficits are ranging between 55mm and 65mm in west Ulster and west Connacht. Elsewhere, values are running at approximately 70mm to 90mm; the east and south of Leinster have been worst hit.