An argument can be made that the term terroir has evolved over recent years, but however you define it, soil remains an integral part of what makes a vineyard’s terroir. Wine is a true expression of where it comes from – a reflection of all the environmental factors affecting the final product. Undoubtedly, one of the most important factors here is the soil type.
Soil science is a relatively niche – and complex – part of the agricultural spectrum. Delving deeper into this discipline will acquaint you with terms like ‘pedology’ (“a discipline within soil science which focuses on understanding and characterizing soil formation, evolution, and the theoretical frameworks for modelling soil bodies, often in the context of the natural environment) and ‘edaphology’ (the study of the influence of soils on living things – particularly plants).
For the more casual wine enthusiast, it is more than sufficient to understand that different soil types have a significant impact on the vineyards planted in them. Different winemaking regions are often characterized by the prevalence of specific soil types, e.g. Bordeaux’s Medoc region has sandy soil, and Cabernet Sauvignon grows well there.
Determining the correct soil type for a particular cultivar can be tricky. The soil must be suitable for both the rootstock, as well as the cultivar grafted onto it. To better understand the soils on a particular site, soil analysis is essential. This involves the digging of profile holes, which allows the soil scientist and viticulturist to evaluate the soil in terms of the factors that help determine the quality and suitability – including texture, colour, organic composition, pH and drainage.
The composition and quality of the soil helps determine not only which rootstock and vine clones would be more suitable to establish, but it can also determine how much irrigation a site will need, which implements will be required for the soil preparation and even how far the plantings will need to be spaced.
At Oldenburg Vineyards, our soils are so integral to the terroir that it is one of our 8 Elements; from the alluvial soils (sandy, rich in organic matter) close to the river, up to the weathered granite and sandstone driven soils on Rondekop itself.
