Selection of Grass and Broadleaf Crops as Catch Crops where Winery Wastewater is Used for Irrigation: A Review

Winery wastewater contains high levels of elements such as sodium, phosphorus, potassium, as well aschemical oxygen demand, sodium adsorption ratio and pH. This may raise concerns regarding the pollutionof the surrounding environment. Environmentally friendly methods such as recycling, i.e. treatment andre-use, where treated or partially treated and diluted wastewater is used for irrigation of agricultural crops,are essential. Irrigation with winery wastewater, which is rich in nutrients, can be beneficial to overall soilfertility as an alternative to conventional fertilizers. However, long-term applications of wastewater mayhave a negative effect on soil physicochemical properties. A selection of crops with nutrient interceptionabilities, preferably for salts, may be ideal for the removal of excess elements from the soil whilst reducingleaching and excess run off. The use of perennial grasses, annual winter growing grains and winter growingbroadleaf nitrogen-fixing annuals as winter cover crops in the South African wine industry has beenextensively documented but their use as summer catch crops intercepting elements applied via wastewaterirrigation has not yet been well researched.