But huge rafts of the pest weed are growing out further and further into the Kaipara River which borders their 155ha property.
Where there were just muddy riverbanks there’s now a thick mat of the weed which in places stretches almost right across the river.
“It’s got worse in the last five years,” Scott said.
“It’s growing out further into the river. It’s that bad that it needs to be sprayed but spraying it is just a band-aid approach. We need a long-term plan.”
In September last year their river flats flooded after rainfall of just 70mm following what had been a dry period.
“It was like a 150mm flood,” he said.
“Usually there would be no problem but we were amazed at how much water turned up.
It was colossal.”
He ranks the flood as one of the worst in the last 20 years but said that what previously had been described as a five-year flood often occurred annually. He believes the thick root system of glyceria traps silt which builds up and inhibits the normal flow of the river.
“It smothers everything.”
While the Narbeys have floodgates on their flat land near the river it will be 10 days after a flood before they can get their stock back on the paddocks, then there is silt to clear. The river drains about 62,000ha out to the Kaipara Harbour from the Waitakere Ranges but because of the weed growth it no longer flushes out properly, being only two feet deep in its upper reaches.
‘Because we need to look after our paddocks in winter we have a huge storage pond area above what we need.’
Another big worry with glyceria is nitrate poisoning which can occur if cows eat it at certain times of the year. Despite fencing off the river and having stopbanks, two of their cows crept into the weed last year, ate the weed, and died overnight.
Murray is the third generation of the family to farm the property and Scott the fourth. He is now co-owner and manager of the property with his wife Sue and their young family. The size of the farm was doubled in 1970 with a lot of development work being carried out on races and fencing. Last season they produced 174,000kg milksolids (MS) from 400 cows and are targeting 180,000 this year.
A 95ha sheep and beef farm on sand country, to the north at South Head, was bought 11 years ago to be used as a runoff. Murray and wife Marie live there managing youngstock, and the cows when they are trucked there to winter over. There’s also a leased block of 35ha closer to the home farm which can be used as part of their grazing rotation and for also for wintering.
Spring got off to a great start with three-quarters of their Friesian/Friesian-cross herd calved in the three weeks from the start of calving on July 26. With 326 cows in milk at the beginning of the last week of August, they’d only had five cows with mastitis and a similar number with milk fever.
“We teatsealed the whole herd and the heifers,” Scott said.
“We’ll definitely be doing that again next year.”
They are breeding towards more Friesian-cross influence in the herd, culling on production and mastitis with an average replacement rate of 22-25%. They haven’t induced any cows for the past 12 years, and used CIDRs on 40 last year.
The 100m of river bank where the glyceria has been cleared shows how far it was encroaching into the Kaipara River.
The bull will be pulled out at Christmas with empties carried over to clean up rough pastures, then sold before winter.
About 160 calves are reared by Scott’s wife Sue each year in a calf shed containing 14 pens on sawdust flooring. Murray said building it four years ago was a great investment as for the rest of the year it’s used as an implement shed.
Last year the Narbeys bit the bullet and built a new 44-bail rotary. Their 32-bail herringbone had been extended several times and was updated with meal feeders and automatic cup removers put in five years ago. But despite starting milking at 2.30pm for the past three years, their two full-time staff, Robbie Travers and John Barber, weren’t cleaning up until after 6pm.
There were also some structural issues with the old dairy so the new rotary was built right next door, which includes automated feeding system, automatic cup removers, automatic teat spraying and a Protrack drafting system. Now they’re washing up after just two hours.
The next big move for Scott is to decide on roofing material for a feedpad. It was built in 1974 for self-feeding silage but there was a problem with cows suffering feet problems on the concrete surface.
Since then it’s always been makeshift, Scott said, having been extended a number of times. But they now believe roofing is needed due to the amount of run-off coming off when there’s heavy rain, which puts pressure on their effluent ponds.
“Because we need to look after our paddocks in winter we have a huge storage pond area above what we need,” he said.
Recently Scott and father Murray travelled with their consultant Don Urqhart, looking at different feedpads on some of his other clients’ farms. They’ve received quotes for plastic and iron roofing, with the effect of their farm’s coastal position and the all-important cost still to be weighed up.
The herd is fed 2.5-3kg of grain in the dairy during their lactation. The Narbeys also make 10ha of maize silage a year which they aim to build up to 15ha. Maize grain is grown on the South Head farm as well, along with about 3ha cut for early grass silage.
“If we get a flood we feed the maize out in spring, otherwise in summer,” Scott said.
They have an eight-year pasture renovation programme to control kikuyu which can’t be eradicated from their pastures. Chicory will be used where land too steep for maize cropping. When it comes to annuals and perennials Tama and Feast are their favoured varieties.
Scott platemeters most of the farm every 10 days and aims to puts the cows in to 3000kg drymatter (DM), taking them out at 1500-1700kg DM residuals when weather allows. The cows are generally grazed on the flat at night with Batt latches used to automatically open gates so they can arrive at the dairy on time to be milked.
Key points
Owner: Narbey Farms
Location: Helensville, northwest of Auckland
Area: 155ha (150ha effective)
Herd: 400 Friesian/Friesian-cross, Breeding Worth (BW) 135, Production Worth (PW) 148, recorded ancestry 99%
Production: 2013-14, 174,000kg milksolids (MS), targeting 180,000 this year
Supplement: 2.5-3kg grain fed in the dairy during lactation, maize silage, silage, and hay.
