Grass growth: Feeling the squeeze
Grass growth rates have taken a dip this week, for some, due to the slower regrowth rates experienced on farms.
Last week, average grass growth rates were running around 70kg DM/ha – across the country.
This week, PastureBase Ireland figures show average grass growth rates of 60kg DM/ha in Ulster, 63kg DM/ha in Leinster, 62kg DM/ha in Munster and 60kg DM/ha in Connacht.
Typically, grass growth takes a dip at this time of year; as farmers try to maintain grass quality through topping, pre-mowing or making bales – slowing the regrowth rate of paddocks.
In addition, the high growth rates these past few weeks have resulted in pre-grazing yields being above target on some farms.
Through the grazing of these heavy covers, there is more stemmy material at the base of the sward, which means that recovery and regrowth is much slower.
When grass growth falls demand will have to be reduced to match growth rates – to avoid pre-grazing yields or cover per cow falling into dangerous territory.
Dangerous territory would be a pre-grazing yield of less than 1,200kg DM/ha and a cover/cow of less than 140kg DM/LU.
Walk the farm regularly so as the deficit in your wedge is identified early and a plan can be put in place to deal with it.
Continue to spread fertiliser – a good guide is a unit of nitrogen (N) per day during the mid-grazing season.
Once grass growth falls your demand will have to be reduced to match the grass growth rate. To do this, concentrates may have to be introduced until growth rates improve and then decreased once they do.
Another option is to bring a paddock which was intended for silage back into the rotation. However, this paddock may need to be pre-mowed, topped or earmarked for bales in the next rotation in order to maintain grass quality.
Finally, good-quality silage could be introduced to reduce your demand.