Technical Yearbook 2023

Pearl millet

Barsweet sorghum

Chicory

Dolichos beans

Weeping lovegrass

Vetiver grass

Fodder radish

Eragostris teff

FIGURE 2 . Photos of the catch crops used on the open land and in the vineyard.

research farm where 10 different fodder producing catch crops were compared to a control where no catch crop was cultivated. In the vineyard, combinations of three different fodder producing summer catch crops and two winter cover crop treatments were compared to a control. Catch crops were not cultivated in the control treatment during the summer, but there were still two winter cover crop treatments. The diluted winery wastewater applied to the open land and vineyard contained high levels of K which could supply more than adequate K if grape yield amounts to 10 t/ha. Substantial amounts of K, Ca and Na were also applied via the irrigation with diluted winery wastewater. Catch crop, soil and grapevine responses, as well as wine quality, will be presented in subsequent articles. Acknowledgements • The project was funded by Winetech and the Agricultural Research Council (ARC). • ARC for infrastructure and resources. • Staff of the Soil and Water Science division at ARC Infruitec-Nietvoorbij for technical support.  References https://www.wineland.co.za/winery-wastewater-for irrigation-part-1/

Cow peas

FIGURE 1. Catch crops used on the open land and in the vineyard.

Abstract Globally, medium to large wineries generate more than 1.5 million litres of wastewater annually, whereas small wineries generate less than 1.5 million litres annually. Irrigation with winery wastewater needs to be optimised to minimise leaching, whilst maximising nutrient removal by means of a catch crop is a necessity. The objective of the project was therefore to identify fodder producing crops that would intercept sufficient K (and Na) applied via irrigation with diluted winery wastewater on loamy sand to sandy clay loam soils in both open land and a vineyard. Diluted winery wastewater was applied to open land on the Nietvoorbij

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

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TECHNICAL YEARBOOK 2023