"It's like cottage cheese, but black," says Peter Barrett of the soil that lies beneath Linnburn Station, his 9300ha beef and sheep station at Paerau in Central Otago.
Above ground, depending on the time of year, sheep may be spotted grazing beneath the gaze of yellow sunflowers, surrounded by a mix of up to 30 other plant species.
Not just a pretty postcard, Linnburn Station is home to 25,000 winter stock units. In fact, this is farming close the limits. Much of the terrain is exposed rocky high country and for the past two years, the already low mean annual rainfall has declined to just 170mm. Temperatures fluctuate from below zero to 40degC.
"We get the extremes here" Barrett says.
Despite these challenges, soil is not tilled, synthetic fertilisers are not used, and just 500ha are under irrigation.
Linnburn's difference is regenerative farming and each year Barrett and staff "experiment" on approximately 1000ha to find ways to improve soil health with diverse pasture species and other regenerative agriculture practices. Which part of the farm they choose, depends on its soil health requirements.
"Every plant sown has a purpose," Barrett says, including to cultivate the soil, store soil carbon, add phosphorus and nitrogen and increase soil life. Barrett has come up with a "matrix" for each species, the functions of which are ranked on a scale of one to 10. Working to each soil test, he creates a unique seed mix to improve it. For example, the deep-rooted sunflowers are grown to cultivate and provide deep passageways in the soil for other species to mine for minerals.
Untreated seeds are sown using a no-till system of a cross-slot seed drill attached to the rear of a tractor. The front end carries roller-crimpers to cut or bend and crush tall pasture plants to form a weed-suppressing mat through which the freshly planted seed can grow.
MPI also believes that soil erosion is probably the number one threat to agricultural productivity in New Zealand. As a geologically young country with steep terrain and high rainfall in places, New Zealand's soils are naturally erosion-prone. Each year 192million tonnes of soil are lost, according to Our Land 2018, a report by the Ministry for the Environment and Stats NZ.
The natural rate of erosion is amplified by agricultural and forestry practices, more than 70% of the total coming off pastureland in some regions of the North Island.
On agricultural land, erosion occurs when tilling loosens and exposes soil to the elements. Any practice that weakens soil structure will also increase erosion, such as overgrazing that shortens plant roots, soil compaction from livestock trampling, and the application of synthetic fertilisers and chemical herbicides that reduce soil biota.
Tilling soil also contributes to climate change. The carbon stored in soils exceeds all other terrestrial environments and the atmosphere combined. Any addition to, or loss of, soil carbon can have huge impacts on atmospheric carbon dioxide. Tilling exposes more of the soil to the air which in turn fuels respiration by oxygen-loving soil microbes to release previously stable soil carbon to the atmosphere in the form of CO2.
The push to avoid tilling is why, in regenerative agriculture, glyphosate is tolerated to suppress weeds so new seeds can establish. At Linnburn, it is applied only in places where there is no suitable pasture to crimp says Barrett, and at only 20% of conventional concentration. Instead they spray bacteria-rich brews that suppress unwanted weeds, as well as biological applications of fish hydrolysate, carbon-rich humate, molasses or yeast that, according to Barrett, feed soil microbes and help different plants to work together.
The profusion of earthworms, bacteria and fungi in the soil are critical, Barrett says.
"You get the engine going, and they [the micro-organisms] build up that carbon and the nutrients and better water retention."
Barrett's experiments are bringing him closer to what regenerative farmers are doing in the US to mimic the natural animal-plant relationship roaming herd animals once brought to the prairies. At Linnburn, "in a perfect situation" stock are brought in for short periods to graze and trample the long pasture. Doing so, "70% gets eaten by the animal and 30% goes back to the ground - and that is regenerative," Barrett says.
The health of Linnburn's animals "are definitely improved but we have a long way to go in that space," he says.
As well as conserving the rain that falls, and reducing the need for synthetic fertilisers made from fossil fuels, this farm of diverse forage benefits biodiversity such as birds and bees.
"All of a sudden you see your whole farm come to life," Barrett says.
Visitors comment they haven't seen anything like it.
Linnburn's regenerative practices have been in place for five years.
Barrett returned from a career in business and finance in the US to manage the farm directly in 2012. Having never practised farming, he followed the conventional farming pathway to "bring it up to speed".
In that first year, trying to grow rye grass and clover as directed, Barrett found himself "sitting in with a fertiliser rep who recommended we put in 2kg of Cropmaster 20 that was supposed to correct everything - and it didn't grow at all!"
The following year the fertiliser company representatives recommended he do exactly the same thing again.
This was Barrett's catalyst for change, "the penny dropped there". In 2014, he spoke to Gabe Brown, a regenerative farmer from the US, and started "experimenting, researching and just trying different things".
Wiser now, Barrett calculates that "the money we could spend to do [prepare, spray, fertilise and drill] 250ha in 2014, we can now do 1000ha with the same money [buying diverse seed] and it's all into growing stuff."
There is still much to be improved in terms of their stock rotations over pasture, Barrett acknowledges.
They also want to get to a stage where they can feed their stock fresh pasture through the winter instead of making silage, and collect and sow all their own seed.
Barrett is one of a growing number of New Zealand farmers reaching out for alternative ways to farm that regenerate rather than deplete their soils and farm environment.
Although regenerative farmers share many of the same techniques, regenerative agriculture is "defined by its outcomes, rather than by its practices", according to Dr Gwen Grelet, a research biologist with Manaaki Whenua - Landcare Research. It has largely been "developed from the bottom up".
For the past 18 months, Dr Grelet has been working with farmers to investigate the environmental, economic and social benefits of regenerative agriculture to New Zealand.
Already, Dr Grelet has more than 200 farmers on the books to be part of her study.
"All I can say is that the interest is rising fast," she says. "At least 7 to 10% of all New Zealand farmers have attended events or reached out to educators or consultants in regenerative agriculture."
While regenerative farming seeks to improve planetary health, will the food it grows also improve our health?
"All of the circumstantial evidence gathered so far points towards improved nutritional quality of food produced regeneratively," Grelet says. But "we need more research to quantify this along with the environmental benefits for New Zealand".
What we grow is as important as how we grow it.
Closely associated with that, is the question of whether we are growing and eating the right food to restore the planet and live healthy lives. That's the question the EAT-Lancet Commission on healthy diets and sustainable food systems sought to answer, motivated by the view that "food is the single strongest lever to optimise human health and environmental sustainability on Earth". According to Dr Sudhvir Singh, director of policy at EAT, the commission's report is the first of its kind to comprehensively address the question of how we can by mid century feed 10billion people a healthy and sustainable diet.
Led by Prof Walter Willett, of Harvard University, and Prof Johan Rockstrom, of Potsdam Climate Institute and the Stockholm Institute, the report took three years to complete, involved the contributions of 37 internationally respected experts and drew on an extensive number of peer-reviewed articles.
"How we get around our cities and towns, and what we eat, have a major bearing on how healthy we are but also the health of our climate and environment as well," he says.
Nearly 11% of the world's population are chronically undernourished while the majority in the Western world are overweight. According to WHO, 80% of premature heart disease, stroke and type 2 diabetes, and 40% of cancer could be prevented by a healthy diet, regular physical activity and avoiding tobacco products. In New Zealand alone, more half of adults over 30 years are overweight or obese.
"We know that from a health point of view, that unhealthy eating is the biggest cause of disease globally in all countries and getting worse," explains Dr Singh. He is also concerned by the shift of the world's growing population to a more Western diet high in animal products.
"That means those challenges are set to compound in the future."
The good news from the EAT-Lancet report - Food in the Anthropocene - is that we are capable of feeding 10billion people a healthy diet that also allows the planet to operate within safe environmental boundaries.
But it won't be easy. According to Prof Willett, its lead author, to achieve this by 2050 "global consumption of fruits, vegetables, nuts and legumes will have to double, and consumption of foods such as red meat and sugar will have to be reduced by more than 50%".
The report calls for a "great food transformation" that involves; a shift towards healthy diets, reorienting agricultural priorities towards healthy food, sustainably intensifying food production to high quality outputs, good governance of land and oceans, and cutting food waste.
So what does this report mean for New Zealand, a nation that prides itself on exporting food to feed the world?
"I think we need to separate out global scientific assessments for a global population and what food is being produced everywhere. That needs to be contextualised when you apply it to any country," Dr Singh says.
For New Zealand, "we must carefully assess our unique food production context".
Questions we need to ask ourselves include addressing the local and environmental impacts of an industry geared to feeding large numbers of people overseas, what kind of nutrition we want that food to provide, and how we can offset some the environmental effects of food production, he says.
Dr Singh sees new opportunities for New Zealand farmers, especially in diversifying their production to grow high quality healthier foods.
"In terms of diseases resulting from food consumption, it's this lack of diversity and lack of sufficient intake of these healthy or protective foods, like fruits, vegetables, nuts and wholegrains, that is a major problem. There is an opportunity to substitute food that is being over-consumed in some countries through growing healthy foods that are lacking in all diets."
In addition, although most New Zealanders, along with the rest of the Western world, eat too much meat and dairy, "there are some parts of South Asia that actually need to increase their per-capita intake of animal protein," Dr Singh says.
"That means there is certainly a role for animal protein in the global food economy. It just needs to be distributed in a more fair fashion, and certainly reduced in Western countries."
So while we need to reduce the overall production of animal protein globally, is there a place for beef and sheep farmers like Peter Barrett, producing meat in ways that enhance biodiversity, conserve water and sequester carbon?
That's definitely preferable to some of the alternatives, Dr Singh says.
"It's not as if we can produce all types of foods optimally everywhere. One of the things about our sheep and beef farms is that they are not as industrially set up as they are say in the US, where there is a lot of grain that's imported and there is a huge number of animals on a small amount of land, generating a lot of waste."
According to Dr Singh, an important question is: Can we improve the environmental outcomes even further?
Through regenerative farming practices, Peter Barrett is confident he is on the right track to do this.
"You have two alternatives," Barrett says. "You either graze it down to one inch and then use synthetic fertilisers and everything to try to grow more product quickly, and decrease your carbon in the ground, and then things leach off and eventually you get to a position where you are not going to be able to keep on bouncing back. Whereas, [regenerative farming] is about understanding that you have to feed your livestock above and below the ground - the worms, the bacteria and fungi.
"We want to create healthy soils, where they create healthy animals and therefore healthy people," he says.
