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An extended dry period during spring had a negative impact on grass yields grown on the programme farms in 2020.
While growth rates did recover in midsummer, grass did come under pressure this autumn on the back of wet conditions in late September and throughout October.
Based on five of the programme farms consistently measuring grass growth on a weekly basis, yields averaged 9.03t DM/ha, down from 9.87t DM/ha in 2019 as outlined in Table 1.
However, yields are running ahead of the 7.93t DM/ha and 7.41t DM/ha grown during 2018 and 2017 respectively.
Based on the outlined yields, improved soil fertility and grazing infrastructure had led to a 22% increase in grass grown on the farms over the past four years.
To allow for a fair comparison of annual growth rates, yields are only calculated from paddocks which had a minimum of 20 weekly grass measurements from April onwards.
Spring growth
Grass yields on the five farms up to the end of April totaled 0.97t DM/ha, down from 1.4t DM/ha in 2019, or a 44% decrease year on year. Yields over the outlined period in 2018 totaled 0.7t DM/ha.
Yields on the individual farms show a massive variation, reflecting the range in land type. The farms located in the west of the province would have heavier soils which are more suited to retaining soil moisture compared to the programme farms in the east.
On Oliver McKenna’s farm, early spring grass growth yielded 1.47t DM/ha compared to 0.27t DM/ha on Alastair McNeilly’s farm.
While spring growth was strong on Oliver’s farm, grass yield was still below the 1.76t DM/ha grown in 2019.
Summer
The lack of rainfall continued throughout May, which added to the difficulties of limited soil moisture and continued to curtail growth.
Yields recorded from May until the end of August averaged 5t DM/ha across the five farms, down from 7.7t DM/ha in 2019, although last year was an exceptional grass growing year.
Again, the location of the farm and soil type had a significant bearing on grass growth. For instance, the two farms located in Co Tyrone did get more rain than the farms in the east or north of the province and consequently grew more grass.
It is also worth noting that the same two farms have been in the programme since 2013 and will also be benefitting from the long term investments made to grassland and soil fertility.
Oliver McKenna grew 7.8t DM/ha over the summer period with 7.7t DM/ha grown on the farm of Declan Rafferty and Aidan Quinn.
In contrast, Paul Jamison saw summer grass yields crashing from 6.8t DM/ha in 2019 to 4.7t DM/ha this year.
Paul’s land type is among the driest of the nine programme farms and the lack of soil moisture during May and June ultimately curtailed grass growth.
Consistency
In Co Derry, Jonathan Blair did record a higher year on year yield of 6.7t DM/ha from May to August, up from 6.4t DM/ha during the summer months in 2019. Yields have been fairly consistent on farm with 6.7t DM/ha grown during summer 2018.
Late season
Grass yields averaged 1.1t DM/ha from September to the end of the season. Again, this was down on the previous year when the farms averaged 1.3t DM/ha during autumn, and well below the 1.8t DM/ha grown during the mild autumn of 2018.
Across the five farms, Oliver McKenna’s farm yielded 1.8t DM/ha from September onwards, with Paul Jamison’s farm producing the next highest at 1.5t DM/ha.
Stocking rates
As several of the programme farms have been expanding cow numbers in recent years, stocking rates continue to increase.
Back in 2016, which is used as a baseline reference year for the programme farms, stocking rates were around 1.8 CE/ha but have since increase to 2.2CE/ha.
Higher stocking rates are not economically viable, or sustainable, unless the farms can grow greater volumes of grass.
Unless this happens, the farmers would be forced to purchase additional winter fodder and increase concentrate feeding levels, undermining the additional income from increased sales from keeping more stock.
Keeping pace
The outlined stocking rate increase is just over 0.4 CE/ha, or a 22% rise from the outset of the programme.
While weather and soil fertility will determine grass growth year on year, the farms have increased grass yields in line with the increase in stocking rates over the programme.
There is no doubt that the farms have faced difficult periods to match grass growth with livestock demand. Such times do test the resilience of the system and the farmer’s nerve.
But overall, the investment in grassland is paying off on the programme farms as more kilograms of beef are being produced and sold annually while keeping input costs under control.
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