Close attention to grass and pasture utilisation will be needed for the rest of the year – despite cooler weather following the hottest start to summer on record.
An average June temperature of 15.8°C eclipsed the previous record for the month by 0.9°C and was 2.5°C warmer than usual. The UK also had just 68% of its average June rainfall with only 52.5mm falling during the same period.
“Thankfully these record temperatures were not matched by record dryness,” said Janet Montgomery of grass seed breeder Barenbrug. “But rainfall was in short supply for much of June, creating drier than average conditions.”
Sunlight hours
The dry spell came at a time when long hours of sunlight and high temperatures mean grass growth is at its highest. “This could really catch people out because pastures haven’t been pumping out the amounts of grass that we’d normally expect.”
That said, pastures are probably in a better position than last year because of rain during July.
But Ms Montgomery says the earlier hot weather will still have an impact on the amount of biomass produced per unit area of pasture.
Her advice to growers depends on what system they’re using. On a set-stocking system, this will necessitate a decrease in the stocking rate, while rotational grazers will need to go for a bigger allocation each time.
“That’s especially important for dairy farmers to observe, because both milk quality and output will be affected if steps aren’t taken to manage that drop-off in biomass.”
Sward damage
Dry grassland should be managed to avoid lasting damage to pasture. “This means not grazing too short; allowing sufficient time between grazing and re-grazing; and, overall, trying to prevent too much damage to the sward.”
While topping might seem counterintuitive in the face of less biomass, it will make pastures more palatable by removing stemmy material. It will also help divert plant energy into vegetative growth, rather than the intensive demands of reproductive growth.
“Keep a track of soil moisture levels, too,” advises Ms Montgomery. “With consistent periods of dry, you’ll need a decision-support process to help you introduce supplementary feeds at the right time.”
With last year’s dry period still fresh in many farmers’ minds, many dairy producers will be wondering how they can make pastures and swards more resilient in the face of a changing climate.
Root biomass
“Changing species can be an effective strategy for areas with consistent summer dry. Unless fields are of an age when they wouldd benefit from a full reseed, autumn overseeding can prove cost-effective to mitigate the effects of future dry periods.
“Consider species that are a little higher in root biomass, such as tall fescue, which will help preserve pastures during dry periods.”
Although cocksfoot and tall fescue have a reputation for being clumpy, coarse and unpalatable, Ms Montgomery says modern varieties are deep-rooting, giving better access to moisture lower down in the soil.
And she adds: “While pasture health is at greater risk the longer the dry period continues – the grass isn’t able to refill its carbohydrate reserves in time to prevent damage – with time and correct management, it will come back.
“It’s easier to allow plants to recover than to put animals’ welfare at risk,” says Ms Montgomery.
