When the soil is healthy, the land’s imprint on the wine is unmistakable. A true expression of place.
We’ve been on a journey of listening, learning, experimenting, and refining the methods that best nurture the soil in our vineyards.
Through this journey, we find consensus between business objectives, fruit purity, and our deeper responsibility to this whenua as tiaki.
A guiding voice in that kōrero is soil consultant and industry legend, Lachy Hynd, who has a lifetime of experience in horticulture.
As told to our writer, Lachy shares his perspectives on soil health and a more pragmatic form of organic viticulture.
Where are you from?
Blenheim. I’m semi-retired now and spent my whole life working in this area, so it’s home.
What led you to your mahi as a soil consultant?
I have a science degree, but didn’t want to work in a lab so went practical working in the orchards.
After selling up my orchard business in 2002, I went into the wine industry which was taking off at the time. I’ve since watched it take up all the land in the province.
I’ve been in many roles, but in the last 5-6 years I’ve been concentrating on soil health and helping vineyards like those at Tohu Wines.
What happened to your orchard business?
In the late 90s, after consolidating from many fruit varieties into just apples and pears, we decided to go organic.
We went down that path along with 8 other orchards but, unfortunately, we all reached full organic certification in the same year. The overseas market at the time was small, and we flooded it.
All of us exited a few years later. We’d all spent our last dollar getting to organic certification, only for returns that were no better than conventional while demanding so much more work!
How do you feel looking back on it now?
Honestly, I don’t regret it in the slightest. It was a huge learning experience and I’ve taken it with me.
It means I understand the pitfalls and the difficulty of organic growing, and how limiting it can be in terms of the tools you have to work with.
When wine growers come to you for guidance on organic methods, what are the biggest challenges they face?
Regardless of whether they want to be organic certified or simply incorporate more organic methods, the main challenge vineyards face is undervine competition.
Because most vineyards don’t create a canopy for shade through summer, they’re constantly battling the growth of grasses and so-called weeds under the vines.
Organic means absolutely no herbicides. The only tools available are cultivating, which disturbs the soil, roots, and irrigations. Or mowing, which selects for grass dominance.
In your view, what’s a better solution for undervine management?
Let’s say you’ve sown clover undervine. You’re going to get grass germination, but organic methods restrict you to options like cultivation or mowing that can take out the whole sward.
With mowing you also end up selecting for grasses first because they’re the fastest to regrow, which further complicates things.
Alternatively, you can use a selective grass killer every couple of years to take out the stuff you don’t want while maintaining the undervine ecosystem. That’s the ideal scenario!
From your perspective, what’s the key to organic viticulture?
The holy grail is finding the living sward.
Sward: an area of land covered with grass or the surface layer of ground containing grass and its roots.
— From Old English 'sweard' meaning 'skin'.
It’s about having a carpet of plant species occupying that space under the vine, that are minimally competitive, but also prevent other “weeds” from growing that would otherwise be competitive.
Growers need to find species that will live in that space effectively, figure out how to plant them there, and then maintain them.
What’s it been like working with Tohu Wines?
What struck me about Tohu’s Whenua Awa vineyard was the immediate difference from conventional vineyards nearby where the grass is mown within an inch of its life through summer.
Anthony and the team at Whenua Awa have tried a few different interrow species and at different heights. It’s been a valuable learning exercise, and as a result of that journey they’ve had excellent soil health for a few years now.
My job is to support them with maintaining it. Sure, there’s more we could do to improve soil health, but once you’ve improved the soil to a point where it’s functional, it’s just about keeping it that way.
How have you been tracking progress with soil health at Whenua Awa?
We’re using the Visual Soil Assessment (VSA) method developed by Graeme Shepherd. You choose your site, dig a square block out of the ground, look at the colour of the soil, the texture, the porosity, the rooting depth, the worm count, etc.
I score all of those categories, come up with a total score, then compare it to 2-3 years ago and to other parts of the vineyard.
We’ve been doing this visual soil assessment every few years using a sample from the same place in the vineyard.
The thing is, a true picture of soil health is a far more complex equation. You can’t just identify a score going up and say “look how well we’ve done!”. So we’ve been looking at more accurate ways to learn about the microbial activity of the soil.
What else can we do to measure soil health?
One test we’re looking at is Hot Water Extractable Carbon (HWEC) testing, which is a lab test that gives us a reasonable proxy for microbial activity at a modest cost.
Why is Hot Water Extractable Carbon (HWEC) testing helpful for a vineyard?
Because it measures the most critical form of carbon in the soil of a productive system: labile carbon.
You’ve got three types of carbon in the soil: labile, reserve, and resistant.
Labile carbon is the most immediate source of energy and nutrition for the soil. Reserve carbon is a more slow-release food source for microbes. Resistant carbon provides a framework for microbial health through aeration and the drainage and storage of water.
In a vineyard, you want to make sure that the ecosystem is working and giving your vines what they need. That’s what you’re looking at with a hot water carbon test.
We haven’t started these tests yet, but I’d advise doing it in springtime, when the soil is responding to some warmth. Then do it again every year, from the same spot.
How has the understanding of soil health in viticulture evolved in recent years?
Awareness of the importance of soil health is much more mainstream now. Just visually, I’ve noticed the change from classic close-mown interrows to many more vineyards putting in green crops or mixed species of swards between the vines.
Growers are less anal about mowing! That’s the understanding creeping in. We don’t have to mow these grass swards. They can add far more value through growing taller, growing roots, and deepening the soil profile.
There’s more understanding of that aspect of soil health coming through the wine industry and I see a lot more awareness. It just takes time.
What do you think is influencing this shift?
Well, just purely from a financial and economic perspective, the cost of diesel is causing growers to reconsider the number of times they get the tractor out. They’re thinking, if I don’t make that pass today, we’ve saved money – and they’ve made the soil better too.
The price of fertiliser is only going to increase with what’s happening overseas. One of the things with developing soil health is that you can back off the fert and use it only when absolutely necessary, which saves you an awful lot of money.
Farmers are astute, they know what’ll affect their bottom line, and fertiliser is traditionally the first thing that gets culled when times are hard. Growers will naturally look at ways to reduce the fertiliser they need, and investing in soil health is a way you can do that.
What’s the ideal balance between conventional and organic methods, in your view?
I think the perfect scenario would be to use a predominantly organic approach, with the option of using something that isn’t certified but serves a useful purpose and gets you down the track of where you want to be.
I’ve experienced this first hand, where you’re stuck and thinking to yourself if only I can use just one selective herbicide every third year, it would save me so much time and money and improve so many things for me. But you’re tied to the box and if you cave you’ve lost your certification.
I call it pecking the eyes out of both to get the best outcome!
Are you still passionate about organic growing?
Yes, absolutely.
Organics have done us a tremendous service by demonstrating that synthetic products aren’t the only way to grow and farm. In fact, there’s a much more positive way to grow that supports the wider environment.
The only drawback with the organics movement is that certification puts a box around a grower in terms of the tools they can use when times are tough.
Ka nui te mihi ki a Lachy for your guidance and generosity to our team on our Whenua Ora journey. For support on your vineyard, orchard, or farm, you can find Lachy and the rest of the Agrownomics team of independent soil health experts here.