Hartenberg has made regenerative agriculture its mission and has also made history in the process.
Hartenberg Family Vineyards recently became only the second wine farm in the world to receive official verification for regenerative practices from the world-renowned Savory Institute. The American-based nonprofit organisation spearheads large-scale regeneration of the world’s grasslands, including grazed vineyards, and the livelihoods of their inhabitants through holistic management.
It developed its Ecological Outcome Verification (EOV) protocol in collaboration with leading soil scientists, ecologists, agronomists and an extensive network of regenerative land managers around the world. Its Land to Market programme sets the standard of regenerative agriculture by working directly with producers and using the EOV protocol that scientifically measures regenerative outcomes on their land. According to the institute, when consumers purchase a brand with a Land to Market label, they can trust that they made an eco-friendly decision that helps address the climate crisis.
The first wine-related verification was awarded in 2021 to Mariah Vineyards in California. In South Africa, Hartenberg has been among the wineries at the cutting edge of regenerative viticulture. The principle draws on the strengths of organic, biodynamic, sustainable philosophies and very little from conventional farming, Hartenberg cellarmaster Carl Schulz says. Its adoption evolved from plans to mitigate the effects of climate change. “Some 18 years ago we engaged a Swiss aquatic engineer to make us more waterwise,” he says. “With that sorted, we started looking at our soils, which is where we are now.”
The initiative is also championed by vineyard manager Wilhelm Joubert, who has been with Hartenberg for over two decades. “You get the adopters and the innovators, and Wilhelm is an innovator,” Carl says. “Our biggest advantage on this journey was the discovery that if you bring ruminants into the vineyards, you can more than double the carbon in the soil. If you have limited water, the only way to protect yourself into the future is to raise the carbon. Our approach is holistic. We can prove that the work Wilhelm has done is easy and cheaper than conventional farming, given all the other benefits.”
Having sheep, cattle and ducks in the vineyards is a cornerstone of Hartenberg’s integrated approach. No herbicides are used. Instead the farm employs biological pest control such as ladybirds and wasps to control outbreaks of mealybugs that are carriers of leafroll virus. Having animals in the vineyards may sound romantic, but there’s more to it, Wilhelm says. “These animals are tools and to get results, they must be managed.”
Hartenberg is situated in the Bottelary Hills region of Stellenbosch and has 90 ha under vineyard. In addition to a small flock of sheep and runner ducks, it has Ankole and Dexter cattle. “We use high-density controlled grazing, which requires moving the animals frequently,” Wilhelm says. There are five herds of eight to 15 animals each to make them easier to manage. They’re used in conjunction with cover crops, planted annually, and some 22 ha of vineyards that have been re-wilded. Soils remain untilled as a way of preserving carbon and avoiding compaction.
Palatable cover crops feed the cattle, providing a steady and fresh supply of natural, wet fertiliser that is in turn immediately beneficial to the soil microbes and improves soil health. Hartenberg uses legumes, brassicas and grains for their specific benefits. Importantly, they have varying root systems, leaf sizes and growing speeds.
“Our aim is to never have bare soil,” Wilhelm says. “In addition to their manure, cattle trample plants into the soil, making them accessible to microbes. Their hooves also create natural pools that help seeds to flourish. We allow the cattle to only take off half the cover crop so the plants can recover quickly.”
The farm has added 12 ha to the 22 ha that have been re-wilded. “Over time, with the cattle integrated and we saw the first trial vineyards flourishing,” Wilhelm says. “We encountered new species and more species.” Important indicator species that returned to the farm include dung beetles. “The system in these vineyards means we can have cattle there from as early as May. Where we use cover crops, grazing can only begin mid-July to October when the vineyards begin to bud. Our goal is to re-wild more vineyards, so we can have earlier and late grazing periods.”
What about the wine?
Hartenberg’s regenerative farming practices may also benefit its wines as a recent experiment proved. In September 2022, the farm split a vineyard block in half. One part was a control where no cattle grazed, while the other was reserved for high-density, controlled grazing. The wine produced from these two halves was analysed and results were compared. The process was replicated in September last year.
The results are:
| Grazed half | Control half | |
| Alc | 14.58% | 15.13% |
| Extract | 27.89 | 28.86 |
| RS | 1.80 | 1.77 |
| pH | 3.52 | 3.56 |
| TA | 6.50 | 6.37 |
| Total tannins | 1649 | 1521 |
| Total anthocyanins | 553 | 525 |
| Polymerised anthocyanins | 34% | 42% |
To explore more articles in our November issue, Movers & Shakers, purchase our digital or print magazine here.
