To what extent does soil health contribute towards what’s in the glass? That’s the question a new study on the effect of soil health on viticulture has answered by proving that it is critical to plant and animal life, as well as the quality of wine.
The method — once condemned at agricultural schools because of the belief that grazing animals spread weeds, and cause compaction in the soil and other damage — defies old thinking by introducing ruminants in a controlled manner to the vineyard. Cattle, sheep and other ruminants not only keep the weeds under control, but they add organic matter, thereby helping sequestrate carbon in the soil.
Regenerative viticulture aims to restore soil health by mimicking natural processes. As soil life improves, so does its ability to absorb carbon dioxide from the atmosphere, making it a valuable tool in combating global warming. Accumulating organic carbon in vineyard soils improves their health, resilience to erosion, and drought resistance due to enhanced water retention.
Conducted by Stellenbosch University and Hartenberg, the study has revealed that a single parcel of vineyard and vintage can produce two different wines, which are poles apart in terms of the aroma, chemistry and flavour, proven by differing levels of alcohol, residual sugar, tannin, pH, total acidity, anthocyanins (pigment) and extract.
Hartenberg, founded in 1692, was acquired in 1986 by the Mackenzie family, who introduced cattle to the property in 2017 to graze fallow lands and areas that required manual maintenance. They discovered that the ruminants significantly impact soil health. Through further research, their viticulturist, Wilhelm Joubert, discovered that grazing animals could also have a positive impact on plant and soil health within the vineyards if they were managed effectively.
In 2010, Joubert — deemed to be the regenerative viticulture pioneer in South Africa — first introduced cover crops to capture nitrogen from the air and improve soil structure and biomass.
Joubert, who had an epiphany after reading Allan Savory’s book Holistic Management, says once they introduced high-density grazing, they started to see nature responding in a way that was hard to believe. They realised that if it works in the fallow lands and pastures, it must work in the vineyards if they apply the same principles of regenerative viticulture.
Early tests conducted after introducing animals to the vineyards demonstrated positive results already within the first season, as the combined effects of the cattle’s treading hooves, grazing habits, saliva, manure, and urine improved soil health.
That discovery set the farm on a course to regenerative agriculture, which has proven to improve the general health and well-being of the property.
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