Grass growth: Onwards and upwards from here

Last week, farmers looked out in despair at their grazed paddocks which showed very slow signs of grass growth.

This was largely due to the low day-time temperatures and cold nights which resulted in a dip in grass-growth rates.

Previously, grass growth had been running ahead of growth rates for 2018 and the five-year average.

Despite this week’s high temperatures, PastureBase Ireland figures show that grass-growth rates for last week were running at 67kg DM/ha on average, while this week they are running below this at 61kg DM/ha on average.

However, rain is forecasted for tomorrow, Friday, May 17, so it is expected that grass growth will be hitting between 80-100kg DM/ha this weekend and into next week.

This will be greatly appreciated by some farmers in the midlands, who are currently experiencing a water deficit.

According to Met Éireann, the soil moisture deficits (SMDs) in well and moderately-drained soils are ranging from 10mm to 23mm and in poorly drained soils from 4mm to 24mm.

With these high-growth rates in mind, farmers need to be keeping a close eye on their average farm cover and on pre-grazing yields to ensure grass is kept under control and grass-quality is maintained.

Maintaining grass quality

We are coming into the time of year when grass begins to enter the reproductive phase – when grass quality begins to decline.

Mid-season management is critical for maintaining grass quality and in turn high-milk production.

Grazing advice mid-season:
  • Maintain a target post-grazing residual of 4cm;
  • Maintain a target pre-grazing yield of 1,400kg DM/ha;
  • Maintain a rotation length of 18-21 days;
  • Cut surplus bales from the poorer-quality paddocks;
  • Walk the farm twice weekly or more to monitor grass supply and grass-growth rates.

Where paddocks are cut for silage, you must remember what comes off must go back – particularly potassium (K).

Slurry is a cheap and very useful fertiliser to replace off-takes – after cutting paddocks for silage – so should be used wisely.