WINETECH Technical Yearbook 2021

PRACTICAL IN THE VINEYARD | JANUARY/FEBRUARY 2021

Understand soil groups to farm better JOHAN DE JAGER: Vinpro, Paarl KEYWORDS: Soil groups, soil forms, soil classification, vineyard block establishment.

THE ESTABLISHMENT OF NEW vineyard blocks is probably one of the wine producer’s biggest financial investments. Soil classification is the starting point for this process and because it is such a complex and technical field, the concept of soil groups can help you to better understand your soils and the origin thereof. Given the current economic climate – not only in South Africa, but specifically in the South African wine industry – it is now more important than ever to make financial decisions that are based on scientific principles and available data in order to protect the producer against risks. The establishment of new vineyard blocks begins with soil classification, which pro - vides you with information about the phys- ical limitations of the soil types and ac- companying factors that will influence the

vineyard blocks, such as structure, texture, increase in clay, stone percentage, depth at which signs of wetness occur (which will influence effective rooting depth), drainage requirements, soil preparation actions and subsequent implement choices, and so forth. The more physical limitations occur in the soil, the lower the vegetative potential of the specific soil form will be, which will also necessitate additional actions to manage the soil effectively. This information is then shared with the viticulturist who uses it to make rootstock and cultivar choices, determine the correct row direction, suggest specific management actions etcetera, which will all be aligned with the eventual wine objective. South African soils are extremely diverse and the soil classification process therefore complicated – we have five topsoils and

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