WINETECH Technical Yearbook 2021

REFERENCES International Society of Precision Agriculture (ISPA) , 2018. “Precision agricul ture definition”: https://www.ispag.org/about/ definition. Rüsch, P., 2001. “Precision farming in South Africa”, University of Pretoria, Pretoria.

were limed 30 years ago according to the old average arrow application. As seen above, the programmes that are currently available interpolate the lime application across block boundaries. We do however manipulate the recommendation so only the representative block is optimally limed. The advantage of this approach is that each block can be evaluated based on its own chemical data and surrounding blocks will thus have no effect on applications. These chemical investigations are performed post harvest, and repeated every three years. In the winter months the imbalances are addressed by using a variety of spreaders which apply the corrections according to the distribution patterns on the specific areas. Thereafter a unique irrigation programme is

compiled per block, taking into account the possible imbalances and new corrections. As the chemical balances start to stabilise and the availability of nutrients and root development improve, the productivity, vigours and balance of the vines will also show a positive upward curve. The nitrogen arrows should then be adjusted every year to ensure that the ideal vigours are maintained. Vigour determinations and evaluations are usually performed by a viticulturist in conjunction with the farm manager or winemaker who takes the specific cultivar characteristics and wine objectives into account. The development of unique and accurate maintenance liming and fertilisation

programmes for the wine industry is a scientific art through which only selected soil scientists can apply their knowledge of soil, terrain and chemistry. The success and implementation of these programmes are dependent on the producer’s willingness to precisely follow the programmes and recommendations, and to apply the necessary actions within the time-specific instructions. This has a direct impact on the productivity, profitability and lifespan of the vineyards. Johan de Jager is a soil science consultant for Vinpro, who special ises in soi l classification, chemical corrections and the development of long-term fertilisation programmes.

Contact Vinpro for independent, precision advice to evaluate your soil health, fertilisation programme, cover crops and viticultural practices.

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