With little or no rain forecast for the next 10 days in Munster and Leinster, some farmers are beginning to get edgy about the prospects for grass growth.

This may seem strange given that soils were waterlogged less than two weeks ago and continue to be wet on heavy soils, particularly in the west and north.

However, evapotranspiration rates were very high during the heatwave last week and there is more hot weather to come next week.

For most of the country, soil moisture deficits are running at 20mm to 30mm, which is normal for the time of year and not in any way restrictive to growth rates.

However, parts of Leinster around Carlow and Kilkenny are higher, with deficits hitting 50mm. Again, I would say that these aren’t restrictive to growth rates, but they are getting close.

Soil moisture deficits

In another week or 10 days, I would expect to see grass growth rates decline due to a lack of moisture where soil moisture deficits go above 60mm or 70mm.

Again, there are only small parts of the country where these will be a factor, and not for another week or 10 days.

This of course also presumes that it won’t rain in the next 10 days either, which is not guaranteed.

However, it is important to acknowledge that in the absence of rain, soil moisture deficits will continue to increase in areas that don’t currently have a soil moisture deficit problem.

It’s also important to acknowledge that if it rains heavily next week there will be no such problems.

So what should farmers do?

I think the first thing to do is to be aware of it and maybe think about things to do in the event of a slow-down in grass growth.

Average farm cover

For me, that involves holding on to grass for a bit longer such as, perhaps, pushing average farm cover up to 200kg/cow rather than the usual 160kg to 180kg/cow level most aim for at this time of year.

If there are surplus paddocks identified for short-term silage, if they are not gone beyond the quality for grazing, should they be grazed now instead of cut for bales?

Ultimately, I don’t think farmers need to take any radical action, but at the same time, farmers need to plan for the likelihood that growth rates could dip in the coming weeks to 50kg/ha/day or below.

For many, this will be below the herd demand so having a bit more grass in the system will help to ride this period out.

Not topping paddocks after grazing is also important as topping reduces growth rates – not topping will help to ensure a quick recovery after grazing.