Growth Watch: Building Bank of Autumn Grass Starts Now

James Fitzgerald and Séan Cummins, Teagasc GreenAcres Advisors, give advice on using the break in weather to boost on growth in August and build grass reserves on your farm. They also get updates from farmers Ciaran Bartley, Co. Limerick, and Peter Byrne, Co. Kildare.
The Advice
With pockets of the country experiencing drought like conditions up to the start of this week, it seem a bit premature to be talking about building up a bank of grass for the autumn. However with the entire country due to receive rain this week, the reduced growth rates due to moisture deficit should be a thing of the past going forward.
Use this break in the weather wisely to apply nitrogen where needs be. This will help to boost growth throughout August and build the reserves of grass on your farm. Nitrogen is better used at this time of year as opposed to September when growth rates are naturally on a downward trajectory.
The aim is to have your rotation length stretched out to a 30 day rotation by the 1st September and to have an average farm cover of 1000-1100kg DM/ha.
On calf to beef farms with early maturing stock, autumn born stock or forward Friesian steers there is the option to start finishing now at grass with 3-4kg of meal. This will help to achieve a good level of finish off grass before slaughter later in the autumn as well as helping to reduce the demand for grass on farm, which will help to build a bank of grass.
August check list:
- Applying Nitrogen now as opposed to later to capitalise on August growth rates.
- Rotation length should be extended to reach 30 days by 1st September.
- Make all land available for grazing to extend the rotation – once fodder requirements for the winter have been met.
- Continue to graze down to 4-4.5cm to stimulate growth and to avoid carrying over dead material into next spring.
- Apply lime where needed if not done so far this year. This can easily be done as ground conditions allow, rainfall levels are increasing and rotation length is increasing.
Ciaran Bartley, Boher, Co. Limerick
Growth: 38kg DM/ha/day
- Demand: 43kg DM/ha/day
- Farm cover: 880kg DM/ha
- Stocking rate: 3.43LU/ha
Growth has slowed somewhat over the past week or two, even though the farm here has received sufficient volumes of rain and has been topped up with protected urea.
A growth rate of just 38kg DM/ha/day was recorded over the past 7 days and, with last week’s demand running at 62kg DM/ha/day, corrective action had to be taken.
The farm cover here is still relatively in a healthy state at 880kg DM/ha, but I decided to start 40 of the heaviest 2020-born steers on concentrates to help reduce the demand.
This animals will be slaughtered in late October / early November. The move to start these steers on concentrates has helped reduce the demand, while moving some of the steers to a block of after grass has also contributed to bringing demand back to 38kg DM/ha/day.
If similar growth rates are witnessed to this time last year, this will mean I will be in a strong position to build covers throughout the month of August.
Peter Byrne, Castledermot, Co. Kildare
Growth: 60 kgDM/ha/day
- Demand: 47 kgDM/ha/day
- Average farm cover: 613 KgDM/ha
- Stocking rate: 3.05 Lu/ha
Going off the results of my last grass measure on Monday, the demand for grass is 13kgDM/ha/day less than the growth rate for the last week (47kgDM/ha/day vs 60kgDM/ha/day). This is the scenario I want to be in at this time of year as it is time to start building up a bank of grass on the farm that I can graze in the back end of the year when growth has stopped.
I am aiming for an average farm cover of 1000-1100kgDM/ha by the middle of next month and so to achieve this I will need the grass growth rate to stay 10kgDM/ha/day ahead of demand between now and then.
Meal will be introduce to the heifers born in the spring of 2020, the bullocks born in the autumn 2019 and some of the better bullocks born in the spring of 2020. This will help to lower the demand for grass and help the average farm cover build. It will also ensure that a good finish is got on these cattle that will be for slaughter off grass later in the autumn.
The Teagasc GreenAcres Programme Advisors have regular contributions here on Teagasc Daily. Find out more about the Teagasc GreenAcres Calf to Beef Programme here.