Climate change: Waikato farmers trial diverse pasture as feed growth set to slow

Kerrie and Anthony Pollock have sewn diverse species on their farm. Photo / Alison Smith

By Alison Smith

Waikato businesses can expect to lose between a quarter and 60 per cent of farm profits by the end of the century unless they adapt to climate change, as ryegrass growth rates slow, according to a new study.

The decrease in summer pasture growth is expected to be more pronounced and extend further into late summer-autumn as the century progresses, the study found.

DairyNZ partnered with Lincoln University and Tatua Dairy Co-operative to assess how prepared dairy farmers in northeastern Waikato are for climate change adaptation.

Specifically focused on ryegrass persistence, pasture growth rates, farm profitability and heat stress for cows, it used a case study farm in Matamata-Piako which was scaled up to assess impacts across the district.

DairyNZ says it has run events showcasing farmers’ use of multi-species crops as a way of coping with the summer dry.

The organisation hosted an event at the farm of Anthony and Kerrie Pollock, who have sewn diverse species on their farm and say they have seen the benefits, guided by an independent advisor.

DairyNZ’s Kent Weston-Arnold told farmers gathered from the district on the Pollocks’ farm that alternative pasture species were more drought-resistant.

Tall fescue, and summer crops such as chicory, turnips or multi-species crops had the potential to mitigate the adverse effects of summer-autumn feed deficits.

Farmers using multi-species pasture

Farm engagement lead for Rere ki uta rere ki tai Nick Collins (left) and Waikato dairy farmer Matt Rout. Photo / Alison Smith

Many farmers in the area are already adopting this diverse regime.

As his dairy herd lazes in a nearby paddock at his Waikato farm, Matt Rout wades through the head-high diverse pasture to reflect on how much his attitude to farming has changed for the better.

With a goal to reduce nitrogen usage, but no idea how to achieve this, he signed up for the Rere ki Uta, Rere ki Tai project, facilitated by AgriSea and funded by Our Land and Water.

As one of 10 farmers in the project, he was guided on how to enhance pasture diversity and build the resilience of soil through approaches that included the use of diversity, biostimulants and Māori science.

The initiative has reshaped Rout’s farming practices and his outlook on the industry.

“Gone are the days where we graze through the spring and we put on nitrogen, we graze, we put on nitrogen. We have weeds come up and we spray the weeds.

“Now it’s more like nitrogen is a tool and we use it when we need to use it.

“It’s more of a relaxed view, not a ‘kill this, kill that’. It makes farming a bit more fun rather than just the same thing every day.”

Rout’s nitrogen usage has plummeted significantly since joining the Rere ki Uta, Rere ki Tai project, from 130 units to 55 units without compromising his animal feed requirements.

Rather than a messy paddock, he sees a flourishing ecosystem that shows him what’s going on underground, and where cows graze on what he would have once considered weeds.

Anthony and Kerrie Pollock's Matamata Piako farm was used as a case study for alternative pasture species. Photo / Alison Smith

“We had a wet winter and I’ve learnt that dock is a sign of compaction - and this place was covered in it.

“But with the use of biostimulants and foliar N at a lot lower rate than I was putting on versus solid rates, the cows eat the dock.

“That means I’m not in the tractor spraying the farm every year. I’m not in the tractor putting on nitrogen every three days to keep up, and I have time to do other things.”

It took his herd a while to get used to grazing in head-high species of different plant families. But after one year his cows now exhibit a preference for the biodiverse paddocks.

“Last year they weren’t so sure. But now, the cows - they love it.”

Embracing soil regeneration was a profound paradigm shift for Rout.

“There was so much stuff in the media about the negative impact of agriculture, and when we were looking to buy the farm I thought I might not be in dairy in 10 years, with everyone saying cows are bad.

“Now that I’ve learned about the nitrogen cycle, the carbon cycle, the water cycle, and how everything links together, I know we need cows.”

Nick Collins, the farm engagement lead for Rere ki Uta, Rere ki Tai, has walked farmers through the use of multi-species crops and alternatives to reliance on agri-chemicals.

He explained how the right combination of plant families worked together to build deeper root systems and assisted with soil aggregation, fostering microbial activity and enhancing soil structure.

This synergy between plants, microbes, and the environment is the future of agriculture, Collins believed.

At the DairyNZ on-farm day, Collins talked farmers through how to assess their soil using “the best tools you have – your eyes and a spade”. - Supplied content