Changing South
The dairy boom has seen cows grazing on the Canterbury Plains increase 12-fold since the 1990s. This intensive farming requires large volumes of water and synthetic nitrogen that are poured on the land. Freshwater scientist Mike Joy says the plains were never able to support this level of dairy farming.
The Canterbury Plains make a major contribution to the dairy industry. But, as Mike Joy, a freshwater ecologist and senior researcher at Victoria University of Wellington, Mike Joy explains, this was not always the case.
“It can’t happen without irrigation,” says Joy. “There is more irrigation in Canterbury than the rest of New Zealand combined to make this landscape in a dairy farming situation.”
He explains that around the same time, there was an explosion in the use of synthetic nitrogen fertilizers, which could be used in conjunction with irrigation to grow more grass and feed more cows. Just like the golden rushes of old, when the word came out, everyone wanted in. According to Stats NZ, the number of cows in Canterbury increased from 113,000 in 1990 to 1.2 million in 2019.
But according to Joy, it has come at a cost – intensive dairy farming is polluting our rivers and aquifers, and it’s only getting worse. He says the problem created is now too big for farmers to fix on their own.
“We need to realize we made a big mistake here, and let’s sort it out,” Joy says, explaining that the big problem with water pollution is nitrates. Cows pee – a lot – and this nitrate-rich urine combines with synthetic fertilizers to dump a whole lot of nitrogen into the soil.
“It just goes straight down, very fast past the root zones through those gravel soils and into the low and low aquifers that flow out this way,” Joy says of the Canterbury region. For our rivers and lakes, it causes toxic algae blossoms that can be harmful to plant, marine and human life.
There is no better example than Lake Te Waihora / Ellesmere, the catchment at the end of the Plains. It is, as Liz Brown, chairperson of local Te Taumutu Rūnanga describes it, the basin at the bottom of the drain. “Whatever we do upstream is going to have an impact on what ultimately arrives in Waihora,” Brown says.
Local Kevin Rouse, who lives on the shores of the lake, remembers how he caught 30 bot a day 30 years ago. Now he’s lucky to get one.
There is also increasing concern about the effects of high nitrate levels in drinking water. While New Zealand regulations are 11.3mg / L, a 2018 Danish study found that anything more than 1mg / L could be linked to an increased risk of bowel cancer.
Iain Piper of Leeston tested his own pit out of concern for his family. After testing his first well at about 17mg / L, he had a deeper well drilled, which tested about 11mg / L. Now, $ 17,000 later, the family is using a reverse osmosis machine to filter their water, which is still at about 4mg / L.
Joy tells Canterbury to have safe drinking water will have to reduce farming intensity on the Canterbury plains by 12- to 24-fold. Environment Canterbury councilor Lan Pham is calling for change with the same urgency. She says farmers have been hit by regulations trying to combat nitrate levels, but the changes are a drop in the ocean.
“All that tells me is that we pollute a little less. It does not tell me that we are actually moving the knob in terms of the extent of change needed to truly have a functional environment. ”
Joy wants Canterbury to consider a scheme applied in the North Island to save the Taupo and Rotorua lakes, and one that does not place the onus on farmers to solve the problem. This involves the central government paying farmers to de-intensify or switch from dairy.
“It’s not the farmer’s fault,” says Joy. “They only do what they can to stay in business. The change must be activated. We need to be able to help farmers get out of the trap they are in at the moment. ”
John Sunckel, Leeston Dairy Farmer and Environment Canterbury councilor, agrees that farmers cannot be expected to give up their businesses without some sort of certainty for the future. “What are you asking me to change?” he says. “What will you give up? Will you give up your home, your car, your retirement fund, your super fund, everything you own and strive for, and walk away from it? ”
But with the support of the central government, Sunckel says he will consider the idea more seriously. “If the government or the people of New Zealand believe that this is what they want, then pay me out, and I will walk away. But in the meantime, don’t just tell me I have to cut cows or do something else if I have no way out, ”he says.
Lan also wants action from above. “I would like to see the central government seize the power they possess to move this knob much further and faster.”