Ewen and Diane Mathieson on their farm. Photo / DairyNZ
Ewen and Diane Mathieson on their farm. Photo / DairyNZ
A Southland farmer says careful planning is essential in mitigating the potential risks of grazing livestock on fodder crops during the winter.
Ewen and Diane Mathieson farm approximately 860 cows and replacement stock at Longwood, west of Riverton. Ewen has 40 years of farming experience, including 12 years dairying.
He practised winter grazing, where livestock progressively grazed areas planted with fodder crops.
Successful winter grazing was all about understanding the farm's soils, planning ahead and managing crops well to keep the cows in top shape, Mathieson said.
"Winter grazing is a means of putting weight on the animals at a time of year when we aren't growing a lot of feed. This is done by storing feed through the summer months and using it in the winter to get through."
It was important to have good plans in place to transition on and off the various crops and animals needed more feed to help them through bad weather conditions, Mathieson said.
He shifted most mobs twice a day, which allowed him to monitor the animals closely and see any issues as they arose.
"We also use back fences to keep cows off areas they have grazed. This allows us to give animals access to these areas if conditions mean they cannot find a dry area to rest. We keep water sources with them so they have access to water all the time."
Paddock selection
Successful cropping involved many factors, from selection of suitable paddocks and establishing the crops, to good grazing management.
The Mathiesons carried out soil tests to assess overall nutrient trends.
"Through this practice we have been able to greatly reduce the use of some nutrients as soil levels mean we don't need to use so much."
Mathieson said it paid to choose paddocks away from waterways.
"If you don't need to use paddocks around waterways, don't. If you do use paddocks adjacent to waterways you need a good five metre buffer to minimise any risk."
He suggested creating buffer areas around waterways or any area where there was run-off, to get some filtration.
The Mathiesons were trialling a few different crops for grazing this year. Photo / DairyNZ
Graze paddocks strategically
To minimise soil erosion and run-off into waterways, paddocks should be grazed strategically, Mathieson said.
"The greater the slope, the greater the risk. There should be at least five metre buffer for any slope. Grazing downhill can help slow down soil sediment loss."
If the gradient was too steep for grazing downhill, Mathieson advised leaving a buffer of 10 to 15 metres at the bottom and graze across the slope, and then graze buffer areas when conditions were suitable.
It was important to identify critical source areas and Mathieson said he was fencing these off "more and more" on-farm.
"Critical source areas that have been cropped can be left until the end of winter before they're grazed, when the weather is fine. They should be grazed last."
Grazing plan
The Mathiesons were trialling a few different crops for grazing this year.
"We will be quite strategic about creating as much value as we can out of the animals we have on farm."
This meant the farm could be run with a lighter footprint so there was less impact on the environment, Mathieson said.
"As we move forward, we will have potentially phased out quite a bit of fodder beet and maybe not grow any at all, but that will require quite a bit of change in our system."
As weather events became more adverse with climate change, the Mathiesons had to keep thinking about what the mitigations could be, such as creating standoff pads, (areas where the animals can go and stand).
"The important thing to remember is don't be afraid to seek advice if you have concerns or there are things you don't understand."
Assistance available for farmers
Extra monitoring and a range of practical support was being rolled out to help farmers achieve immediate improvements in intensive winter grazing practices.
DairyNZ consulting officers were also on-hand to review the plans, alongside farmers.
Beef +Lamb New Zealand's new farm plan also included a specific chapter on forage cropping and will be delivering specific workshops on this chapter over the coming months to assist farmers with their planning.
Wintering resources, including the Break Fed Guide, are available at dairynz.co.nz/wintering and Winter grazing/Forage crop grazing information is available at Beef + Lamb New Zealand.
MPI's 2021/2022 Intensive Winter Grazing Module - Protecting freshwater health is available here.
