According to Met Eireann, soil moisture deficits are ranging from around 25-80mm across the country, with the driest conditions across the south and east.

Heavy rain this week may be enough to improve growth rates in some places.

The drought conditions can only be considered to be broken when there has been enough rain to take the soil back to within about 15% of field capacity. This generally means more than 50mm of rainfall is required for most places.

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How soon can we expect growth to recover? Looking back at 2018, after the drought broke in August, PastureBase data showed that recovery varied substantially across the country.

In locations that had been less affected, growth recovered to normal levels within a week.

In contrast, heavily burnt areas required substantial and repeated rainfall events over the following three weeks before there was any substantial recovery in growth.

When rain arrives after a drought, up to half of the grass available will die and decay quickly. Consequently, where large parts of farms have burnt yellow grass, cows will continue to require the major part of their intake from supplement over the next two weeks (100-160kg DM per cow).

The DM content of new green growth will be low (below 15%) and root reserves will also need time to recover, so it is important to maintain rotation length at 25 days for the next two weeks.

In the short term, pre-grazing covers on many farms are low (500-700kg DM/ha) and it is essential that cows have adequate access time and space to high-quality silage and other supplements to maintain an overall intake of 18-19kg DM.

As rainfall levels return to more normal levels, continue to walk the farm weekly and keep an eye out for the variation in regrowth between paddocks. There may be areas of the farm with heavier soils, which are still growing better.

Such areas will benefit from being grazed sooner, outside of the normal rotation, and may also respond to soiled water application.

Previous dry summers have shown us that when dry soils are rewet, a pulse of background N is released. Farmers should hold off on fertiliser application for the next two weeks to avail of this mineralised N.

Swardwatch

  • Continue to walk the farm weekly and keep an eye on regrowth between paddocks.
  • Heavier parts of farms with green cover could respond to small amounts of rainfall quickly and should therefore be grazed sooner.
  • Even where substantial rainfall occurs, nitrogen applications should be delayed as the soil will have good N reserves after the dry period.

    • Dairy farmers

    Paidi Kelly – Croom, Co Limerick

    We are feeding 4kg each of good-quality silage and straights. We are keeping rotation length at 30 days.

    We got 20ml of rain on Monday and expect to get a further 10ml this week. Pre-grazing yields are low at 900kg, but grass quality is good. Our newer grass clover swards are green and should recover quickly.

    We stopped spreading fertiliser at the start of July and will wait for grass to recover over the next 10 days before applying more.

    Our milking platform stocking rate is 2.8LU/ha, so we hope we can recover normal growing conditions quickly. We still plan to do some reseeding during August.

    Stocking rate (LU/ha) 2.8

    Growth (kg/ha) 17

    Average farm cover (kg/ha) 283

    Yield (l/cow) 19.5

    Fat (%) 4.62

    Protein (%) 3.62

    Milk solids (kg/cow) 1.7

    Concentrates (kg/cow) 4

    Seamus Wims – Celbridge, Co Kildare

    We are on a dry farm and typically carry a lot of grass into July. The farm is very dry right now and grass quality is only average.

    We have been grazing to 4cm, so we have wasted no grass and quality will be good when we get rain. We only got 4ml in the last few days so we don’t expect any real change to growth.

    Pre-grazing yields have dropped to 650kg and we are on a 30-day rotation. We’ve been feeding 3.5kg of a barley, maize and distillers’ mixed ration, and 8kg of good-quality silage for two weeks. We’ve spread no fertiliser since the start of June, so we will blanket spread 20kg when we hopefully get rain at the end of this week.

    Stocking rate (LU/ha) 3.5

    Growth (kg/ha) 10

    Average farm cover (kg/ha) 306

    Yield (l/cow) 15.5

    Fat (%) 5.00

    Protein (%) 3.67

    Milk solids (kg/cow) 1.4

    Concentrates (kg/cow) 3.5

    Aidan Lawless – Johnstown Castle, Co Wexford

    We start calving the autumn herd on 20 September. Half of the herd is currently dry, which has reduced demand. Both the dry cows and the milkers are at grass full time.

    The farm is green and grass is good. We got 15ml of rainfall earlier this week, which will let us keep growing – but we need more rain for autumn grass.

    We took our second cut of silage on 15 July and that area has grown well. We are on a 30-day rotation and can house dry cows if needed. Pre-grazing yields are 950kg DM but will fall to 700kg by the end of the week.

    With no fertiliser spread since 3 July, we intend to blanket spread the farm with 10kg N/ha next week.

    Stocking rate (LU/ha) 3.1

    Growth (kg/ha) 27

    Average farm cover (kg/ha) 625

    Yield (l/cow) 19.0

    Fat (%) 4.61

    Protein (%) 3.85

    Milk solids (kg/cow) 1.7

    Concentrates (kg/cow) 6