The inland valley soils are low in carbon so little nitrogen is absorbed. Instead, nitrogen bubbles up in groundwater springs and elevates nitrogen levels in the river which is a tributary of one of Southland’s major rivers – the Mataura.
Aaron Wilson milks about 900 cows at a low stocking rate of 2.2 cows/ha but is worried even a low stocking rate will one day not be enough to lessen the farm’s impact on the environment.
Last year he won Environment Southland’s Individual Environment Award, recognising his use of fodder beet for wintering and also for starting the Balfour Water and Land Group in 2013.
It got him thinking and he decided to do a Kellogg Rural Leadership Course to see if he could come up with some way to stop the “nitrogen cascade” through his land and into the waterways.
And he did – a feedpad set-up where the effluent is collected in a holding tank before passing through carbon-filled containers where bacteria convert nitrates anaerobically into nitrogen gas. Solar panels and electricity would power heating tubes to keep the bacteria working even when it’s cold.
In bad weather the holding tank stops too much effluent entering the carbon-filled containers and overwhelming the bacteria, and by keeping the containers sealed off from the air and with a constant flow of effluent passing through them the bacteria produces inert nitrogen gas and not nitrous oxide, which is a greenhouse gas.
The carbon for the bacteria could be woodchips and the containers could be plumbed to use gravity to move the effluent from the holding tanks through them.
Although his idea is only conceptual, it’s got the attention of several scientists also working on the problem of removing nitrogen from waterways.
“I would like to get a lab version working, to see what it could do, and maybe one day on farm as well,” Wilson said.
But with his farm working expenses at about $3.60/kg milksolids and debt servicing another $2 on top of that, the current payout is not going to allow him to get a digger.
And he’s cautious about the benefits of a pad. His initial idea was to stand the cows off on it for half the day, capturing half the nitrogen that would have gone into the groundwater but once a feedpad was built, he could carry all the feed to the pad and not have cows grazing winter crop in the paddock at all.
And then, he might as well put a roof on it.
“We’re the country that invented the jet boat and the electric fence but this generation is growing up looking overseas for answers and I don’t think farming like they do in Europe is the answer for us,” he said.
“If farmers know the problems they will come up with the solutions themselves that will work for them. It took me a few hours on Google and reading books to figure out a feedpad that might work. I haven’t got a university degree, I’m not a scientist. I’m just a farmer.”
That “just a farmer” tag is also something he’s starting to think about.
“The Kellogg course really showed me that farmers can sit around a table with others and hold their own. We’re pretty clued up on things.
“What we need in all this turmoil happening at the moment is to look for opportunities. We will be stronger at the end of it and we could lead the world once more in low-cost dairying. We’ve just got to figure out how.
“Things are broken now but we need to focus on a game plan that will see us through the next 10 to 15 years and we need to forget the negativity and get back on our feet.
“We need to know whether we should be making more milk or less milk or doing something completely different.”
He believes New Zealand’s clean, green image and story is not just important for tourism, but also for milk powder.
“We can’t bring 40 million people to NZ every year, but we can take NZ to 40 million people worldwide.
“And how we do that is our unique story. How we farm the land, how we care for it and how each generation wants to leave it in a better state than the generation before.
“If the world knows that our milk powder is the best milk powder in the world, that it’s made by cows eating grass on farms owned by families that care, then that must add something to its value.”
Wilson knows a bit about family-owned farms. His parents, now retired in Balfour but still directors in the company, first owned the land and two of his three kids want to farm it, even though they’re still at primary school.
“One is dead keen on tractors and the other on stock so it could work out to be a good combination.
“Although whether they want to take it on will be up to them. They have to want to do it.”
The sheep and beef farm was converted in 2007 and now a 54-bail rotary is working to the max to accommodate the 900 cows on the 400ha platform. There’s also a neighbouring 180ha and a 70ha runoff nearby at Lumsden.
It allows the farm to be completely self-contained, making its own hay and balage with the cows wintered on fodder beet.
New cultivar Suga Beet has also been grown for the past few years with Wilson importing a lifter from Holland several years ago.
“We lift it every day in the autumn and spring and feed it to the cows in the paddock. By lifting it every day we don’t lose the leaves.”
The crop is high-energy and lets him have high days in milk with winter only 60 days at the Lumsden runoff.
“It also lets me transition the cows on to the fodder beet before they get to Lumsden without any worries.”
As well, the Suga Beet means they don’t have to buy palm kernel or grain on the spot market.
“With such a low stocking rate we only have to have a good rain in the summer and we’ve got too much grass.
“If we grow 45kg drymatter/day/ha we’re in surplus so if we bought palm kernel on contract to get the lower price we could end up not using it.”
The solution of Suga Beet which can be left in the ground until needed, or stored on a concrete pad, is working so far and making Wilson think about what else he can do to make the farm economic in low payout years as well as how to reduce nitrogen entering the waterways.
“If you have problems you find solutions. That’s part of our pioneering spirit. That’s who we are.”
