Terra preta for the vineyard

Researchers stumbled upon a mystery in the Amazon region at the end of the 19^th century. They discovered a deeply dark but extremely fertile soil that did not at all fit the natural conditions. The soils of the tropical rainforests are anything but rich in nutrients. The researchers found answers among the Indians. Already thousands of years ago, the indigenous people practised shifting cultivation with slash-and-burn methods. To improve the fertility of the soil, they mixed plant residues, composted waste, human faeces and plant charcoal. Through fermentation, this resulted in terra preta, the black earth.

Terra-preta substrates have meanwhile also experienced an upswing. In scientific trials with cultivated plants, the Free University of Berlin demonstrated a predominantly positive effect, provided that the plants tolerate the increased pH value of the soil.

In the Wonnegau region of Rhinehessen, winemaker Andreas Huppert discovered terra preta for his vineyards a few years ago. Together with his son Leonhard, he even produces the black soil himself. The vegetable charcoal is mainly made from the wood of vines and is mixed with green cuttings, straw and horse manure and fermented airtight under a foil with the help of microorganisms.

The Hupperts have already spread their terra preta on more than ten hectares. For Andreas Huppert, however, the focus is not on improving the growing conditions for his vines. Rather, he is concerned with contributing to sustainability. At some point, his winery should become climate-neutral. Terra preta has enormous potential in this respect. Through its worldwide use in agriculture, “biochar” could bind seven per cent of the world's CO₂ emissions annually, or about 2.6 billion tonnes. By comparison, that's more than a third of the emissions generated by road transport (2019: 18%).

Image: Weingut Huppert

In addition, terra preta can contribute to strengthening the resilience of vineyards in times of climate change. In the dry Wonnegau region, which has little rainfall, the vines in the terra preta plants benefit not least from the greater water retention capacity, which is becoming increasingly important for the supply of nutrients in the increasingly hot and dry summers. At the same time, the black soil protects the vineyards from erosion caused by the more frequent heavy rainfall events.

We tasted three wines from the Huppert winery that come from terra preta vineyards.

The Chardonnay was left on the fine lees for a long time, was only weakly sulfured and bottled unfiltered. The yellow-fruity aroma profile reveals the grape variety, but this complex and self-contained stoic from the house of Huppert has absolutely nothing in common with the reductive Chardonnays with forced and striking flinty notes that have become fashionable.

The rosé could not be more idiosyncratic. Not a fresh and slender terrace wine for hot summer days, but an expressive wine full of character with exotic fruit and fine tannins, which are somewhat reminiscent of an orange wine.

Image: Weingut Huppert

The cuvée of Portugieser and Pinot Noir is exciting. In addition to the red wine typical aromas of cherry and dried plum, light-fruity and floral components surprise here, which embed themselves harmoniously. The tannins are of high quality and already show a good polymerisation in the relatively young stage, which is beneficial for the further development.