Beating the giant buttercup and planting a herbal mix to see them through the summer dry is the recipe for success on a Golden Bay farm. Anne Hardie reports.
Graham Ball’s cows are spoilt for choice when grazing his Golden Bay farm, with paddocks serving up a selection of timothy, cocksfoot, plantain, chicory and clover as well as ryegrass in a mix designed to combat the summer dry without irrigation.
These days, his son-in-law Graeme Crawford oversees the day-to-day management of the farm as a contract milker. It’s his fourth season on the farm, though he knows the area well as he and his wife Lorraine were sharemilkers on a nearby farm more than 20 years ago and won the 1997 Top of the South Sharemilkers of the Year competition.
At some stage he decided it was time for a change and swapped muddy gumboots for salty spray on a local fishing boat. It was a stint that lasted a decade before he returned to the land four years ago in the bush-clad valley just north of Takaka.
It’s a farm undergoing a transformation as in the past three years they have regrassed about 40ha of the 150 effective hectares into a herbal ley and will continue to regrass the remaining paddocks.
‘It does make a big difference spraying twice compared with paddocks we’ve sprayed once. It’s quite disheartening when you spray a paddock for buttercup and three months later it’s just as bad.’
While the summer dry which normally lasts for six to eight weeks is the main drive to develop a herbal ley for the herd, the never-ending battle with giant buttercup is another reason for spraying out paddocks for resowing and then there’s the benefits of the individual species to draw nutrients from the pakihi soil and provide a balanced diet.
The farm meanders up the Te Waikoropupu Valley, close to the famous springs of the same name, stretching more than 4km from one end of the farm to the other beside the no-exit gravel road, sometimes only a paddock width before touching the regenerating bush on the surrounding hills.
Multiple streams and ditches dissect the farm so paddocks vary in size from 0.5ha to 3.5ha and with the dairy in the middle, can mean a 2.5km walk for the 370-cow herd. Though the cows are milked as one herd, Crawford split-grazes the paddocks which means allocation is worked out on metres of pasture per day. He says that may sound simple enough, but it’s quite a challenge.
Because it’s a hike for the cows from the furthest paddocks, milking switches from twice-a-day at the beginning of the season to three milkings in two days about Christmas and then once-a-day for the last six weeks of the season which finishes in mid-May. It’s a flexible regime, depending on the season.
In this part of the world, the annual rainfall reaches about 3.5 metres, so it’s not short on water. But it still gets dry if only for a few weeks which knocks production and Ball says spending hundreds of thousands of dollars on irrigation for such a short time doesn’t stack up. Plus, there’s the other benefits from establishing a herbal ley throughout the farm.
Giant buttercup has been an ongoing battle on many Golden Bay farms and Crawford says its invasive habits will dominate 80% of the pasture if allowed to go unchecked and even with control measures, they still have paddocks with buttercup making up 50% of the pasture. The farm is a trial site for giant buttercup research and the latest trials use repeated topping to thwart the pest, following research with various spraying regimes.
Spray resistance is a problem, so now Crawford tops paddocks five times a year to reduce the dominance of buttercup and the regrassing of paddocks gives them the opportunity to spray twice to hit the buttercup seedlings that follow the first spray. After the initial spray in spring, they sow a chicory crop for summer, then spray that off in late February to sow the herbal ley.
“It does make a big difference spraying twice compared with paddocks we’ve sprayed once. It’s quite disheartening when you spray a paddock for buttercup and three months later it’s just as bad.”
Spraying out paddocks and regrassing 15ha a year is as much as they can take out of the round and they are going to drop that a bit, so it will take a while to complete the entire farm and buttercup will build up again. The reality is, fighting giant buttercup is going to be a life-long battle.
“Taking 15ha out makes our autumn quite testing,” Crawford says. “We only give it a light graze in autumn and it’s not fully back into the rotation until spring, so we’re dropping it back to 10ha next spring.”
For a period at least, the resown paddocks will have a mix of species dominating buttercup and adding a range of benefits into the system. Into the mix they opted for 15kg/ha of Trojan ryegrass as it seems to be more resilient on pakihi soils through summer, 12kg/ha of Greenlea cocksfoot for the summer dry, 3kg/ha of red clover, 4kg/ha of white clover, 2kg/ha of Tonic plantain, 1kg/ha of Puna chicory and 1kg/ha of Timothy. It’s a mix that was chosen for protein through the summer dry, as Crawford explains.
“The research shows that during a dry summer, ryegrass is very low in protein, which means ME (metabolisable energy) drops and crude protein drops. So we had to come up with a plan as we didn’t want to rely on irrigation.”
Chicory offered 12.5-13 megajoules (MJ) ME/kg drymatter (DM) and crude protein of 20-26%, while both chicory and plantain have tap roots that pull up nutrients from the soil through summer.
“That opens up your soil,” Ball says. “With our wet soils we need that oxygen content in the soils because pakihi can seal off very quickly in the wet. By doing all these things and building your carbon on these soils, you end up with very friable soils that are very soft – so you don’t drive on it in winter!”
The other challenge with pakihi soil is that it has a low holding capacity until organic matter is built up, which means it loses sulphur and potassium. To counter that and the high rainfall, fertiliser is applied little and often.
RPR is applied once a year as the main phosphate fertiliser and then four dressings a year include 20kg/ha of soluble phosphate, 25kg/ha of potassium and 30kgs/ha of sulphur. Nitrogen is kept to a minimum for environmental reasons, with just 30-50kg/ha applied, split between two dressings during spring.
Meanwhile, the higher protein for the cows is balanced with small feeds of wheat or barley through the season which are starches that are higher in carbohydrates. This year it was wheat mixed with palm kernel, totalling 100 tonnes fed to the cows in the shed throughout the season.
Ball says they also focus on managing protein so they are not losing too much through urine patches, thus again reducing the environmental impact.
The result of regrassing and managing giant buttercup is a lift from 9.8t DM/ha five years ago to 11.5t which includes the herbal ley and older pastures. Last winter, when the older pastures were growing 4.5kg DM/ha/day, the herbal ley was growing 15kg DM/ha/day.
The impact on milk production from that lift in pasture has been hard to judge because the past two seasons have been far from normal. This season, production will be down about 3% on the previous season, with about 143,000kg milksolids achieved, and that was about 3% down on the season before that which was a perfect year climatically, beginning with a dry spring.
Though while the farm dropped 3% this season, it fared better than many Golden Bay dairy farms which averaged a drop of 6-7%, with some farmers forced to drop to once-a-day milking in spring. After a very wet spring, just 10mm of rain was recorded during November and December and Crawford dropped to 3in2 milking on December 12, just before the climate turned summer on its head and parched ground became sodden. In January and February alone, they recorded 1100mm of rain. It was not a typical Golden Bay season and challenging to say the least.
Through the dry, the herbal ley performed better than other pasture on the farm and ryegrass pastures still have bare patches where it dried off completely.
“The climatic conditions have more influence than the grasses. We can minimise it and that’s what we’ve done, I think. The herbal ley was better than everything else and we’ve still got patches in the ryegrass where it dried out completely. Where we pugged through the wet spring hit the herbal ley hard though because clover hates pugging and it destroyed it in those areas.”
The pakihi soil also dictates herd management. Cows head off the farm for 50 days in winter to two nearby runoffs that total 80ha, returning for an August 1 start of calving. The herd is predominantly smaller Friesian cows and the goal is to get the liveweight down to about 480kg to lessen the impact on wet pakihi soil. On the milking platform they run a stocking rate of 2.4 cows/ha and the overall stocking rate with the runoffs is 2.2.
A lower stocking rate suits the layout of the farm, the pakihi soils, lack of irrigation and lessens any impact on the environment, while the herbal ley also fits in with a philosophy about feeding the cows. Ball says cows simply need a balanced diet and while they love their new herbal mix, it is also a good way for them to get all their trace elements.
Farm owners: Graham and Michelle Ball
Contract milkers: Graeme and Lorraine Crawford
Location: Te Waikoropupu Valley, Golden Bay
Area: 150 effective hectares
Herd: 270 predominantly smaller Friesian
Stocking rate: 2.4 cows/ha on milking platform
Production: 143,000kg MS
Pasture grown: 11.5 tonnes of older pastures and herbal ley
New pasture mix
15kg/ha Trojan ryegrass
12kg/ha Greenlea cocksfoot
4kg/ha white clover
3kg/ha red clover
2kg/ha Tonic plantain
1g/ha Puna chicory
1kg/ha of Timothy
Reasons for herbal ley
Summer dry without irrigation
Higher protein through summer
Regrassing to battle giant buttercup
Balanced diet for cows
Long tap roots to open up pakihi soil.