ADAPTING farming practices in response to extreme weather events is now very much part of every farmer’s job description, according to the farmer-funded research and innovation body AgriSearch.
“Recent Met Office data has shown long-term trends towards warmer and more extreme weather events in the UK, with annual average temperatures rising since the 1980s. The 2018 grazing season was a tale of two halves for Northern Irish farmers, with the late wet spring and summer drought conditions impacting on forage availability, yields and quality of crops and milk production,” said Jason Rankin, General Manager of AgriSearch who organised GrassCheck dairy walks on two farms this summer.
The walks on Henry Stewart’s farm at Stewartstown and Andrew Dale’s farm in Limavady demonstrated just how different the 2018 grazing season was on farms across the Province due to the impact of the weather.
This year Henry’s farm was in drought conditions for most of June and July while Andrew’s farm had one of its best summers in 20 years. Initial GrassCheck on-farm data for 2018 shows a two to three tonne variation in total dry matter yield between eastern and western farms, with the summer drought having a big impact on total annual grass yields in the east. In addition, grass growth recorded on plots at Hillsborough and Greenmount was approximately 20 per cent lower than the 10-year average.
Henry milks 220 Holstein/Friesian cows in an autumn and spring block calving system producing on average 8,200 litres per cow. Henry places a strong emphasis on good grassland management across the 280-acre farm. At grass, cows are strip grazed in two groups. Henry has unique cow roadways which are covered in artificial grass mats. The grass has numerous advantages on his farm in reduced lameness, long durability and improve cow speed on walkways.
“Weather dictates our entire farming policy,” he said.
“We are not in County Cork or the south of England. So, going down the road of calving the cows exclusively in the spring months was never going to be an option. However, we have always known that making better use of grazed grass had to be a priority for the business.”
Henry continued: “From a grazing point of view that meant establishing a realistic paddock network on the grazing block. We are also committed to making good quality silage.”
Before committing to GrassCheck Henry was measuring grass dry matters by physically harvesting grass within quadrants. Each was half a metre by half a metre in size. “Now I use a plate meter,” he said.
“I measure all the paddocks on a Friday and Saturday and record information on AgriNet (online decision support tool.) The most striking impact from my involvement in the GrassCheck project has been the distinct improvement in milk from forage yields.
“I have also managed to reduce our reliance on concentrates, without any reduction in yields and make better use of grazed grass throughout the growing season. An excellent example of this has been our ability to graze a proportion of the herd until the end of November this year,” he explained.
“Normally all the cows would be housed much earlier in the autumn.”
Henry concluded: “Our involvement in GrassCheck also confirms that it is possible to use grazed grass as a valuable feed source for both autumn and spring calving cows.”
Andrew milks 110 Fleckvieh cows, with the herd currently calving from October to April. The 12-month rolling average milk yield for the herd is 6,635 litres/cow. He has taken a very proactive approach to grassland management, which is important in order to maximise the grazing potential from a limited grazing block of just 15 hectares.
In doing so, Andrew has split seven fields into 12 with temporary wires and strip grazes out paddocks. The installation of an underpass has also helped improve access to paddocks and allowed Andrew to restructure his grazing. During the main grazing season Andrew feeds zero-grazed grass twice daily to cows at milking time, with the cows grazing full time.
“GrassCheck has allowed me to accurately measure the grass growth achieved on the farm and how this can vary on a day-to-day basis,” he said.
“Maximising the quality of the grass available to the cows at all times is crucial. This is the only way to achieve optimal levels of performance from the herd. I will regularly take out paddocks that have become too strong for grazing out of the rotation system during the height of the growing season. There is a mower on the farm and a local contractor will do the baling and wrapping for me.”
According to Andrew, he is currently achieving grass dry matter yields of between 10t and 12t per hectare across the farm. “Some of the paddocks are producing up to 14t per hectare,” he added.
Looking to the future, Andrew wants to improve dry matter output across the farm. “It is still early days,” he added.
“I have only been involved with GrassCheck project for the past two years. Above all else, it has allowed me to assess the performance of each paddock. The next step is to regularly soil test the entire farm with an emphasis on those poorer performing paddocks. This will allow me to spread lime, re-seed, drain and fertilise accordingly. The objective is to maximise the grassland potential of the farm. It’s an approach that makes total economic sense, given that grass is the cheapest feed that farmers can offer their cows.”