Technical Yearbook 2024

FIGURE 4. Variation in (A) N, (B) P and (C) K in the grapevine roots sampled from the 0 - 30 cm, 30 - 60 cm and 60 - 90 cm soil depth layers at LOR1.

FIGURE 5. Variation in (A) Na and (B) Cl in the grapevine roots sampled from the 0 - 30 cm, 30 - 60 cm and 60 - 90 cm soil depth layers at LOR1.

Conclusion Results showed that there was a substantial accumulation of salts in the soil at the LOR2 experimental plot after only two years of the in-field fractional use (augmentation) of winery wastewater with raw water for vineyard irrigation. Furthermore, the accumulation of elements, particularly Na and Cl, in the permanent structure of the grapevines at the LOR2 shallow sand experimental plot could explain the poor response of the grapevines to the winery wastewater irrigation. Under the prevailing conditions, the wastewater irrigation had to be terminated, and this particular soil/ climate combination should be considered unsuitable for the long-term application of winery wastewater. Results showed that the high levels of Na and Cl in the permanent parts could decline if the grapevines were irrigated with raw water. On the deep sand LOR1 experimental plot, no detrimental effects of the in-field fractional use (augmentation) of winery wastewater with raw water for vineyard irrigation were observed. 

References https://www.wineland.co.za/in-field-fractional-use-of-winery-wastewater-with-raw-water-part-5/

For more information, contact Carolyn Howell at howellc@arc.agric.za.

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TECHNICAL YEARBOOK 2024