Farmer devises DIY sustainability
At a time when New Zealand’s farming practices are increasingly placed under the floodlight, a South Waikato farmer has developed an integrated operation to reduce his nitrate footprint while increasing productivity from the same land mass.
The farmer is large animal vet Ian Scott and the farm is Scott Holdings.
Located at Okoroire, just a few minutes drive from Tirau between Cambridge and Putaruru, the farm is a high-input, highstocking, high-production operation.
The system Ian has developed to achieve sustainable-intensive farming resembles a virtuous circle, encompassing year-round milking, a largescale wintering barn, a maize/ryegrass growing platform, and the exporting/recycling of nutrients.
A 40-hectare deer farm, home to 400 red and wapiti deer, adds to the system with each element feeding into the other, culminating in a high productivity/low N footprint.
He says that it’s unlikely farmers can keep doing what they have always done in New Zealand; turning more farmland into dairy farming.
To remain viable and competitive internationally, farmers must find ways of incorporating new technology into smarter farming systems.
“I get really frustrated with all the hooha about intensive dairying. I can produce milk through my system at twice the N efficiency as your average, low-stocked, grass-only dairy farm.
“I take only half the amount of nitrogen to produce a kilo of milksolids as some other people. My N footprint was only 57 at the last overseer review.”
From a milking platform of 58ha, he peakmilks 350 friesian and kiwicross cows through a 40-a-side shed with an increasing Fonterra wintermilk contract.
With year-round milking, Scott Holdings produced 195,000 kilograms of milksolids last season – 3362kgMS per hectare.
“The shed’s now bigger than the cow numbers we’ve got, but it’s big enough so that if I decided to exit deer or retire, the whole farm could be turned into a big dairy platform milking 500 cows.”
Running a split herd, about a quarter of the cows will calve in autumn, but Ian is gradually increasing this to maximise the winter-milk premium.
By moving his heifers forward to calving on June 20 and milking all cows for 320 days a year, he has achieved a long lactation period for each cow and increased their efficiency.
Fifty hectares of maize followed by Italian ryegrass is grown from a 66ha support block that is also home to some replacement cows and young stock.
“We grow about 1200 tonnes of maize silage depending on the season,” says Ian.
“It’s mostly used for our own purposes, but the deer go through a fair bit of it. We’re probably at the stage where my cows are getting four-plus tonnes of input or more per cow.
We also use palm kernel, tapioca and soy. Nothing is conserved on either the dairy unit or the deer platform, with all material coming from the support block.
Ian’s sustainable system revolves around the export of nutrients that have been collected in his wintering barn and recycled on the maize-growing platform.
This system has allowed for an increase in soil organic matter to between nine and 10 per cent in a constantly cropped area.
“Once you have high stocking rates and high input, the only way to minimise your nitrogen loss and environmental footprint is to capture surplus nutrients coming onto the farm and passing through the cow, then exporting them back off the farm. So my system is basically a nutrient recycling system.”
The floor of the wintering barn is covered in 1000 cubic metres of wood chips, which collect and absorb the nutrients.
Twice a year, up to 400 cubes of woodchips are collected and exported to the support block where they are cultivated and become a big part of the nutrient requirement to grow the following year’s maize crop. Last season 700 cubes were exported to the maize-growing platform.
This year’s exceptionally wet Waikato weather has necessitated a further partial woodchip clearance.
During winter milking, and in the autumn once you start losing nitrogen, cows spend more time in the barn so that the amount of nitrogen going back into the grass environment from urine is decreased.
“If the weather is bad, they might go out in the paddock for only four hours a day over a couple of days, and because they’re not getting a lot of grass, it doesn’t take them long to eat it. So, I can control the number of cows that are on the home platform during the peak leaching months.”
After they have dried off for their 45 days of rest, the cows move off to the support block and are on the ryegrass that is grown after the maize silage has been harvested.
In the next season the maize will gather up any nutrients that pass into the slightly deeper layers of the soil profile because their roots go down a metre and a half.
The maize is then harvested and comes back to the dairy platform as energy. And what is the deer’s role in this virtuous farming circle.
“The deer provide a valuable role in the grazing ecosystem—a tool for pasture management.
“They clean up grass that the cows were too fussy to eat, ensuring the quality remains high for when the cows return.
In recent years, this was conflicted when the deer were earning more than cows.”