The science of soil sustainability and wine (in South Africa)

By Agatha Pereira

Q&A with Heinrich Schloms, interview by Agatha Pereira

Heinrich Schloms is a soil scientist at the department of agriculture at Western Cape in South Africa.

Agatha recently interviewed him at the Climate Change Leadership conference in Porto, Portugal.

What is your definition of sustainability in the wine industry?

Sustainability is when you give more than you take. If we take the soil, there’s a soil economy going one there. For instance, imagine something like the organic content in soil is like a bank account. If you take money out of your bank account all the time but you don’t put money in, you’re going to run out of money. Natural resources come with big bank accounts, big organic content. If we plough our soils too much and if we manage it wrong, we’re going to burn up all the carbon and that’s unsustainable. We must give more to the soil than we take to make sure.

Can the wine industry afford sustainability, and with so many vineyards not being profitable, what is realistic to expect, do you think?

Heinrich Schloms

The wine industry is going to shrink in South Africa. It’s already shrinking. We shrunk from 100,000 hectares to 85,000 hectares in the last few years. The thing is the amount of hectares couldn’t just climb and climb. Like everything in life, you get peaks and you get troughs. Maybe the drop in the amounts of wineries is actually maybe a good thing. The people that’s left are those people that’s doing it right and it’s those people that’s doing it sustainably, not the chancers. The falling numbers isn’t always a bad thing.
What also happened is our price of wines is going up. It’s price and demand. That is something that we’ve been needing for quite a while because our wine prices were way too cheap so because of the lower supply, our demand is going up. That’s actually helping the people that’s left to be more sustainable because we were going in a unsustainable way. We can’t sell our wine for R20 a bottle because it cost more

Beyond the vineyard, whose responsibility is to drive sustainability, like yourself, do you work in partnership with other companies or the scientist?

Many scientists. If you take the wine industry, there’s so many companies involved in the wine industry. If you take the Western Cape, in the places like Paarl where I stay, it’s almost half the people staying in Paarl is in some way connected to the wine industry. If the wine industry fails, it will have a detrimental shockwave through the whole of the Western Cape. It’s the biggest generator of GDP in the Western Cape, so everybody is responsible, everybody is accountable.

Is there a sense of togetherness in sustainability in South Africa, do you reckon?

Not always but it’s definitely growing. It’s evolving definitely. I can feel that the people are realizing more and more that if we don’t start being sustainable, we’re just going to move backwards. If you see the pesticides limitations are getting worse. We’re not allowed to spray certain chemicals on our crops anymore and all these types of things. If we take the people that buys our product, they’re getting more and more strict on what we allowed to do. If one farmer does it wrong, and the product goes oversees and it gives South Africa a bad name, it’s going to have a massive effect on the rest of us.

We’re starting to realize it’s not just about ourselves, it’s about the whole face of the South African image. The South African farmers doesn’t work well together always but we’re realizing that if we don’t work together in terms of everything, if it’s marketing and just the image of South African wines, it’s not going to work.

I do soil surveys, which is finding the best soils for planting vineyards. That’s my main priority. That’s going to be more and more important is finding the right soils to plant your vineyards, not just planting it there because it’s closest to your house. I think that’s going to be the most important thing for sustainability is actually finding the right places to plant the vineyard, instead of just comfortable places. I do surveys to find the resources to plant a vineyard.

What I normally do is, I go to a farm, and I dig profile pits 1.6 meters deep across the farm, about four profiles per hectare. I survey each and every single one of them. Look at the physical properties like clay content, water-holding capacity, effective depth, all that stuff. I draw soil maps to determine where’s the better soils and the weaker soils.

So that you have a nice soil map so that you know where’s your resources and according to the soil map, you can start planning where to plant what type of vineyards or where to plant first. That’s a first step to sustainability is doing things right, planting the vineyard on right place because if you start off planting the vineyard in a place where it’s not suited or low-potential soil but then it’s not going to be sustainable. The choice where to plant is the most important step because then you can do whatever you want afterwards. Do mulching and irrigation and marketing. Yes, my job is actually the first step of growing a sustainable vineyard.

They need to get it right from the beginning. You can’t pull out a vineyard afterwards and plant it in other spot and you can’t change the soil’s physical properties much.

Yes. There are so many farmers that just blindly plant the vineyards in spots without chemical or physical rectification. They just hope that it will grow and then they want to fix it afterwards. It’s not something you can fix afterwards. You must do it right from the beginning. That’s what my lecture is going to be tomorrow.

There are no shortcuts. If you want to be sustainable, if you want to plant a vineyard that’s going to make money, you must do all the steps right. Not step 5, 6 and 7. You must start at step 1, which is site selection and soil survey. Then the planting, soil preparation, chemical amelioration. All that stuff.

Is there a way of correcting it after the vineyard is planted?

Yes. You can put a plaster on it, and do a little bit but normally, no. Stuff like soil PH. You can’t rectify subsoil that is acidic afterwards. You need to mix in the lime deep. Lime’s not very soluble. It’s not something you can throw in and it dissolves and go deep into the soil. All stuff like that. I guess it’s like going to the doctor when your old legs will be already rotten and the doctor says, “If you’d just came earlier, I could have saved your leg, but now you can come with me to remove this old leg.”

About the author

Agatha Pereira

Agatha Pereira is co-founder of Sustainable Wine and a corporate executive with 15 years management experience. For the past 12 years she has been working with HNW Venture Capitalists operating in 27 countries. During this time, Agatha has also taken a number of Winemaking, Viticulture and WSET courses and has developed an extensive network of wine experts, collectors, producers and distributors.