Water quality: Acid test for water testing

ENVIRONMENT WATER QUALITY

A Winton farm has conducted tests on water leaving the farm as part of a slew of environmental initiatives on a farm surrounding a lime quarry. Story and photos by Karen Trebilcock.

When Steve Smith, general manager of AB Lime near Winton in Southland, makes a mistake on the company’s dairy farm he wants to tell everyone about it.

“Someone has to try things and it might as well be me. When it goes wrong, I have to suck it up, but I also want other farmers to know so they don’t do it too.”

With catchment groups, dairy discussion groups and schools visiting the farm he gets to show the good and the bad.

“We’ve been testing the water leaving the farm ever since we started dairying eight years ago and all it’s done for us is show the results of Environment Southland’s water testing is correct.

“It’s cost us $60,000 so far to do it.

“Farmers tell me they’re thinking about water testing and I say don’t bother, spend the money on something else, something that will actually improve water quality.”

He became general manager of the lime works in 2008 and, with lifestyle blocks beginning to encroach on the quarry, the company started buying land.

Then there was the $8-plus payout year and by August, in five months, Steve had an 80-bale rotary up and running with 930 crossbred cows milking on 374 hectares.

“We never got the $8.65 payout. We got the $4.30 payout.”

For the first two years they had a lower order sharemilker then Jaime McCrostie came onboard and won the Southland-Otago Dairy Industry Farm Manager award in 2018 on the farm. Mitchell Smith is now manager with five other staff running the 950 peakcows.

Steve never set out to be a dairy farmer and is still to put a set of cups on. From a sheep and beef farm at Waikaka in Southland, he graduated from the University of Otago with an accounting degree and started work at Ravensdown in both IT and accountancy.

From there he worked in project management, implementing computer ‘We’ve got State Highway 96 running right through the centre of the farm and I’ll get random texts from people driving past saying the farm is looking good or not so good. We’re in a real fishbowl here.’

Above: AB Lime’s crossbred herd keeping their feet dry on the feed pad by the dairy. Right: AB Lime general manager Steve Smith.

systems here and across the Tasman but got sick of the travel.

“I was on a plane back home one day and I opened up my passport and counted 40 stamps – it was the days when they still stamped your passport. The job at AB Lime came up and I applied.

“I don’t like to say they got a two-forone deal but my wife Fiona had been lecturing at Lincoln University and she got the job here as health, safety and environment manager. She’s now chair of Environment Southland’s Regional Forum on freshwater too.”

As well as the lime works and the dairy farm, Steve also runs the landfill in the old quarry. A Class 1 landfill, it takes all of Southland’s household waste as well as specialised industrial waste.

It’s engineered with impermeable layers making sure any leachate is collected and taken to the Invercargill wastewater plant for treatment. Methane is captured and used in the lime kilns, reducing the lime works’ need for coal by 20%.

Although excellent environmental practices for a lime works and landfill are well known and researched throughout the world, how to dairy farm on wet, clay Southland soils is not and Steve is trying whatever he can think of to leave as small a footprint as possible.

“We’ve got State Highway 96 running right through the centre of the farm and I’ll get random texts from people driving past saying the farm is looking good or not so good. We’re in a real fishbowl here.

“I come to work every day to protect the environment.”

One of his projects this past winter has been a composting wintering barn. In possibly one of the best examples of upcycling onfarm, where limestone rock was once kept after it was quarried, 115

cows were wintered for 10 weeks on metre-deep wood shavings and fed silage.

On three sides of the pad are the walls of the former quarry and the roof came from the Clyde Dam project decades ago.

“Our cows go to Tarras in Central Otago on grass and silage for the winter which costs us $40 each way per cow just for transport. That’s a lot of low hanging fruit.

“We were thinking about putting a roof on our feed pad by the dairy so I was doing lots of research about barns and started reading about composting ones. We decided on 115 cows because in Southland you need a consent to house 120 cows or more.”

The shavings were raked using an aerator on the back of a tractor every day during the winter, a 15-minute job, and the heat coming off the composting action kept the cows warm.

“They really loved it, were really happy on it. As long as you keep it aerated it’s aerobic, so there is very little methane or ammonia. There’s no smell at all.”

Now the cows are off it, aeration is done every second day and Steve reckons the shavings will still be good for next winter.

Wintering cows on crop on the farm he considers not an option. With heavy clay soils and rolling hill country, the potential losses of nutrients and sediment are too great.

“We’re okay with nitrogen but sediment, phosphorus and E.coli in high rainfall events are something we need to keep an eye on.”

They’ve identified 25ha of steep pasture to plant in native bush as well as riparian buffer zones. At the top of the farm, 63ha of native bush which has limestone outcrops has been fenced off and a 10year, $1 million-management plan has been underway for three years.

“We ecosource the seeds and grow the plants at our own nursery. Just doing the pest control in the bush has had amazing results. The neighbours have got on board as well and we’re going to develop walkways for the public through it.”

A sediment trap at a natural pinch point has also been built, reducing sediment losses by 60% and phosphorus losses by 40%.

“We’re at the head of two catchments. The Tussock Creek and an arm of the Winton Stream catchments and we’re involved in the Mid-Oreti Catchment Group so we’re doing everything we can to look after it.”

Planned start of calving is August 1 for the cows and a day earlier for the heifers. Cows are crossbred, with their smaller stature suiting the hill climbs but inseminations were with Friesian straws last season to get the black and white genetics back up.

“You can’t get a F12 herd of cows and keep it,” he said.

With no irrigation and only 110kg N/ha used, the stocking rate is 2.5/ha but last season wasn’t the best with production at only 430kg MS/cow.

Left: The first of this year’s calves. Above: AB Lime have their own native plant nursery using ecosourced seed.

Ready for another winter – the composting barn.

“On the first of December we had so much grass I decided to stop all supplement going through the in-shed feeders. Production dropped 13% overnight and we never made it back up. I lost my nerve in February and started putting concentrates back in but it was just too late.

“We were using palm kernel, corn gluten and DDG and I was just trying to reduce our costs and footprint by stopping it. I’d read that feeding concentrates gave you more milk but didn’t make you any more money.

“I’ve now realised that cows can only eat 18kg drymatter of grass a day, even if you give them more, but they can eat another 2kg of concentrates and that’s what keeps production up.

“Now I want to see where we can get to and then pull back on the concentrates somehow but still try to maintain production.

“We’ve got milk meters in the dairy so we know the best cows and the worst cows. In February, our top 50 cows had done season-to-date 25,000kg our bottom 50 had done 11,000kg MS.

“If we could get rid of that bottom 50 cows and replace them with 25 cows the same as our top ones, then that is 25 less cows we need to have.”

Being a lime supplier, although the farm still has to pay for it, soil pH is up at 6.2, higher than fertiliser companies recommend but Steve thinks it works.

“We soil test every two years and put on what’s needed. We’ve got our effluent going on 137ha through a pulse system with k-lines. Last year we didn’t need to apply any super on a large part of the farm.”

A DairyNZ climate change ambassador, he’s urging all farmers to know their greenhouse gas emissions.

“Know your number and have a plan in place to reduce it. It’s not about reducing milk production, it’s about being more efficient in how you get it, and reducing your environmental footprint.”