The Secret is in Our Soil
The core idea of regenerative viticulture 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.
Whilst vines are hardy plants, we understand that it is important to sow cover crops to prevent the negative effects of monoculture plantings. We annually change and sow multiple different species of cover crops, each adding specific nutrients to the soil. These nutrients are like a diverse buffet for the microorganisms living in our soil, enriching its health and fertility.
Our Viticulturalist, Wilhelm Joubert, started playing with this idea in 2010. He began planting cover crops like Medics, which can capture nitrogen from the air and improve soil structure and biomass, and White Mustard, which is a natural bio-fumigant, to combat nematodes. By 2019 our approach evolved to what it is today: prioritizing purpose-specific, multi-species cover crops that increase biodiversity, soil health, and that can serve as nourishment for our animals.
A key question we ask ourselves regularly is “what waste are we generating?” and then we look for solutions. As a business we generate waste in our restaurant and cellar. When you visit our restaurant, we ensure that all the food waste is composted using the Swedish Jora system, where it transforms into nutrient-rich, dark compost. The compost finds a home in the extensive gardens on the farm. In the summer, we produce around 200 kg of compost 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, and annual grape harvest skins and stalks are all mixed and composted. A year later the resultant compost finds its way back to the vineyards.
High-Density, Controlled Grazing
In 2017, we introduced cattle to our farm, not just as roaming lawnmowers, but as collaborators in a groundbreaking approach to vineyard management. We discovered that, when managed correctly, grazing animals can significantly enhance plant and soil health within our vineyards. The cattle’s impact is multifaceted: their hooves gently aerate the soil, the pulling effect from the way they graze stimulates plant growth, and even their saliva, manure, and urine contribute to soil rejuvenation.
We stand at the forefront of this innovative technique, diligently measuring soil microbiology and its impact on the wines crafted from these experimental patches, comparing them to the traditional norm.
Back to Nature
Rewilding our Wetlands
Nestled within our 170-hectare estate lies a sprawling 65-hectare wetland, once choked by invasive plants. Now standing as a symbol of our commitment to rewilding the land, it is a vibrant ecosystem teeming with native flora, including bullrushes known for their fibrous root systems that are natural water filters.
Starting in 1995 and spanning a decade, we embarked on an ambitious mission to reclaim our wetlands from invasive alien trees like Syringa, Black Wattle, Blue Gum, Pine, Port Jackson, and Sesbania. This extensive restoration effort has yielded remarkable results, with increased soil water levels and longer run-offs after rain, fostering the ideal conditions for the indigenous plants to flourish.
But the true magic of our wetland lies in its role as a haven for wildlife. Here, amidst this protected sanctuary, more than 85 different bird species find refuge, alongside a variety of animals such as bucks, wild cats, and caracals. Notably, our wetland is also home to two of the best indicators of pristine ecological health and an absence of pollution: frogs and Cape Francolin. Their presence underscores our commitment to farming in harmony with nature.
Biological pest control
At Hartenberg, we’ve embraced a holistic approach to pest control, fostering a harmonious relationship between our vineyards and the indigenous insects that protect them, creating healthier vines and ensuring winemaking for generations to come.
Since the early 2000s, Hartenberg has been pesticide-free, pioneering the use of historically indigenous insects to control pest insect populations instead. This charmingly includes the use of ladybirds to help control outbreaks by preying on mealybugs, notorious carriers of the leafroll virus. We also release two indigenous wasp species, Anagyrus and Perminutus, to prey on mealybugs. The end result of this is that all vineyards younger than twenty years continue to be virus free.
Integrated Production Of Wine (IPW)
At Hartenberg we farm organically and adhere to the IPW (Integrated Production of Wine) scheme codes of conduct which focuses on sustainable wine production. The Integrity & Sustainability seal, which can be found affixed to the neck of all our wines, is not just a mark; it’s a promise. It assures consumers and buyers alike that our wines have been meticulously crafted through environmentally conscious and sustainable methods. Compliance with the IPW guidelines is assessed annually and audited independently.
Hartenberg is blessed with water from 5 springs that flow from the top of the Bottelary Hills. Careful management and investment in protecting this resource means we have never, in over 300 years, needed to connect to mains water. The spring water is of a very high quality and flows through a network of pipes around the estate to where it is needed.
Almost 2 decades ago, Dr Eric Smollgruber, an Austrian aquatic engineer, advised Carl on how to improve our wastewater management to ensure that every drop is reused. We recycle all the wastewater from the cellar, tasting room, restaurant, and houses on the estate. Hartenberg’s water has been a closed system for 20 years; the water reused over and over again.
Another way in which we are pioneering the conservation of water is through investing in sub-soil irrigation. This super-effective method comprises irrigation pipes that are buried in the ground so that water is drip fed directly to the roots of the vines. This eliminates the water wastage typically associated with above-ground irrigation, where evaporation can take its toll. Hartenberg has also switched from daytime to nighttime irrigation. This simple shift in timing has profound results, reducing evaporation by 10-20%.
Pressure Bomb Reading
Hartenberg purchased the first Pressure Bomb Reading kit in South Africa in the late 1990’s. This test allows a high level of accuracy in determining the water needs of a plant and is the only instrument of its kind to measure levels of water in the plant as opposed to soil moisture levels.
The implement measures the amount of pressure needed to push sap out of a leaf’s stem. This pressure is the same as the pressure the plant needs to exert to extract water from the soil. From this reading a viticulturist can judge what amount of water stress the vine is experiencing and consequently the need to irrigate or not.