In the heart of the Stellenbosch winelands, lies a 170-ha swathe of land where a team’s dedication to cultivating soil and environmental health has led not only to the revival of exquisite biodiversity but also to the crafting of exceptional wines.
Decades before ‘regenerative agriculture’ became the buzzword it is today, the people of Hartenberg Family Vineyards were already fully committed to the cause of building a healthy environment from the soil up.
Leaving the land in a much-improved state than in which they received it is, after all, the philosophy with which the Mackenzie family acquired the property in 1986 and continues to underpin every aspect of life and work at Hartenberg.
“Even if we did not realize it at the time, our regenerative agriculture efforts stretch back decades,” says long–standing cellarmaster and production director Carl Schultz. “It’s in our DNA and the golden thread that runs through everything we do as a team – from vineyard to cellar to tasting room to restaurant and beyond.”
What is regenerative agriculture?
While Regenerative Agriculture has no single agreed-upon definition, the core idea revolves around working with nature, instead of against it, to increase land productivity and biodiversity. A key factor in achieving this is the restoration of soil health and fertility through increasing soil organic matter and closing the carbon cycle by farming in harmony with nature.
Of course, this is by no means a new concept, but rather one that has formed part of indigenous knowledge systems for millennia. In recent decades, it has re-emerged as a holistic alternative to the degenerative effects of mechanised modern agriculture on ecosystems.
Hartenberg’s approach
At Hartenberg, regeneration efforts come in a wide variety of forms. In 1995, a decade-long process was launched to remove alien vegetation from the property’s 65-ha wetland area. This has led to the return of a wealth of indigenous flora and fauna, including 130 different bird species, small antelope such as duiker and steenbuck, as well as caracal, Cape fox and black-backed jackals. It has also resulted in increased soil water levels and longer run-offs after rain.
Since the early 2000s, Hartenberg has also been pesticide-free, pioneering the use of historically indigenous insects to control pest insect populations instead. Along with Vergelegen Estate, and the guidance of Dr Gerhard Pietersen, a leafroll virus protocol and standard operating procedure was developed. This charmingly includes the use of ladybirds to help control outbreaks by preying on mealybugs, which transmit the disease. Two indigenous wasp species, Anagyrus and Perminutus, also have an appetite for mealybugs and are released in big numbers. The end result of this is that all vineyards of eighteen years and younger are (still) virus free. This in itself is a remarkable achievement when measured against industry standards.
During this time, Carl also ended the use of rodent bait stations (which often lead to unintentional secondary poisoning) around all buildings, opting instead to place fifteen nesting boxes on the south eve of the estate’s buildings. These currently house twelve breeding pairs of Barn Owls. A healthy population of free-ranging Eagle Owls also help to balance the fauna population.
The sowing and annual changing of multiple cover crops ensures increased soil microbe diversity and avoidance of the negative effects of monoculture. Along with this, controlled grazing of cattle in the vineyards is proving to have a positive effect on plant and soil health. Hartenberg is pioneering this technique and is currently in the process of measuring soil microbiology as well as the effects on the resultant wines made from these test patches to compare to the norm.
Natural stands of indigenous vegetation have been established in a learnt attempt to create natural barriers between young and old vineyards on the property.
Finally, all the food waste from Hartenberg’s restaurant and residences on the property is composted using the Swedish Jora system. The compost finds a home in the extensive gardens of the estate. In the summer, around 200 kg of compost is produced per week and 50 to 100 kg in the winter. The compost is applied as mulch and nurtures the health of the soil.
On a bigger scale, all garden refuse, annual grape harvest skins and stalks are all mixed and composted. A year later the resultant compost finds its way back to the vineyards.
Much of this work has been done under the leadership of Carl and viticulturist, Wilhelm Joubert.
Regenerative agriculture, the way of the future
“Ultimately,” says Wilhelm, “when we change and improve the microclimate, plant and soil health through these practices, it must also have a positive effect on the wine.”
“It is our responsibility, goal and a privilege, to participate in the restoration of creation, by farming regeneratively,” he concludes.
“Climate change is the slow poison of our time,” says Carl. “We will be expected to produce the same amount of agricultural product, with less water, in a warmer climate. Due to its positive impact on the environment, regenerative agriculture is truly the only antidote.”
More information about regenerative agriculture interventions at Hartenberg
- Reducing pesticides
Since the early 2000s, Hartenberg has been pesticide-free, opting for biological control instead. This includes controlling Leafroll Virus, which is carried in the saliva of female mealybugs, by using ladybirds who prey on mealybug pupae.
- Cover cropping
In 2010, Joubert, started experimenting with nitrogen-binding cover crops like Medics to improve soil structure and biomass, as well as White Mustard, which is also a natural bio-fumigant, to suppress nematodes. By 2019, this evolved into making use of more purpose-specific multi-species cover crops as a tool to achieve a specific goal. Now, the emphasis is more on biodiversity, soil health and cover crops that can be eaten by animals.
- Holistic planned grazing
Hartenberg first acquired cattle in 2017 to graze fallow lands and areas that otherwise had to be kept tidy with implements. Upon further research, Joubert soon discovered that grazing animals could actually have a positive effect on plant and soil health in the vineyards too, provided they are managed correctly.
The combination of the treading effect from the cattle’s hooves, the pulling effect from the way they graze, as well as their saliva, manure, and urine all improve soil health and tests already showed a positive result in the first season since animals were brought into the vineyards.
