Technical Yearbook 2023

Soil pH (KCl) Soil pH (KCl)

K (cmol (+) /kg) K (cmol (+) /kg)

0.0 0.0

2.0 2.0

4.0 4.0

6.0 6.0

8.0 8.0

0.0 0.0

0.2 0.2

0.4 0.4

0.6 0.6

0.8 0.8

1.0 1.0

-80 -70 -60 -50 -40 -30 -20 -10 0 -80 -70 -60 -50 -40 -30 -20 -10 0 -80 -70 -60 -50 -40 -30 -20 -10 0 -80 -70 -60 -50 -40 -30 -20 -10 0 -80 -70 -60 -50 -40 -30 -20 -10 0 -80 -70 -60 -50 -40 -30 -20 -10 0 -80 -70 -60 -50 -40 -30 -20 -10 0 -80 -70 -60 -50 -40 -30 -20 -10 0 -80 -70 -60 -50 -40 -30 -20 -10 0

-80 -70 -60 -50 -40 -30 -20 -10 0 -80 -70 -60 -50 -40 -30 -20 -10 0 -80 -70 -60 -50 -40 -30 -20 -10 0

Soil pH (KCl)

K (cmol (+) /kg)

0.0

2.0

4.0

6.0

8.0

0.0

0.2

0.4

0.6

0.8

1.0

Soil depth (cm) Soil depth (cm)

Soil depth (cm) Soil depth (cm)

Pre-treatment Raw water Diluted winery wastewater Pre-treatment Raw water Diluted winery wastewater Pre-treatment Raw water Diluted winery wastewater

Pre-treatment Raw water Diluted winery wastewater Pre-treatment Raw water Diluted winery wastewater Pre-treatment Raw water Diluted winery wastewater

Soil depth (cm)

Soil depth (cm)

Ca (cmol (+) /kg) Ca (cmol (+) /kg)

Mg (cmol (+) /kg) Mg (cmol (+) /kg)

0.0 0.0

1.0 1.0

2.0 2.0

3.0 3.0

-80 -70 -60 -50 -40 -30 -20 -10 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Soil depth (cm) Pre-treatment Raw water Diluted winery wastewater -80 -70 -60 -50 -40 -30 -20 -10 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Soil depth (cm) Pre-treatment Raw water Diluted winery wastewater -80 -70 -60 -50 -40 -30 -20 -10 0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Soil depth (cm) Pre-treatment Raw water Diluted winery wastewater Mg (cmol (+) /kg)

Ca (cmol (+) /kg)

0.0

1.0

2.0

3.0

Soil depth (cm) Soil depth (cm)

Pre-treatment Raw water Diluted winery wastewater Pre-treatment Raw water Diluted winery wastewater Pre-treatment Raw water Diluted winery wastewater

Soil depth (cm)

Na (cmol (+) /kg) Na (cmol (+) /kg)

0.0 0.0

0.1 0.1

0.2 0.2

0.3 0.3

0.4 0.4

0.5 0.5

Na (cmol (+) /kg)

0.0

0.1

0.2

0.3

0.4

0.5

Soil depth (cm) Soil depth (cm)

FIGURE 2. The average soil contents of the vineyard determined pre-treatment and after three years at the end of the trial in May 2020.

Pre-treatment Raw water Diluted winery wastewater Pre-treatment Raw water Diluted winery wastewater Pre-treatment Raw water Diluted winery wastewater

Soil depth (cm)

was expected given the large amounts of salts added via the irrigation 4 and the inability of the catch crops to take up these salts. 5 Irrespective of catch crops, the application of diluted winery wastewater (T1 - T6) rather than raw water (T7 & T8) in the vineyard tended to increase soil K, particularly in the 0 - 150 cm soil layer (table 2). This was to be expected given that winery wastewater contains high levels of K and substantial amounts of K were applied via irrigation. 4 Furthermore, the catch

crops absorbed only a small amount of the elements applied via the irrigation. 6 Similar findings with respect to soil K have been reported previously where diluted winery wastewater was used for vineyard irrigation 2 or where the in-field fractional use (augmentation) of winery wastewater with raw water for vineyard irrigation was used. 3 The ExPP increased for treatments in the current study where diluted winery wastewater was used for irrigation rather than where raw water was used for irrigation (data not shown). Similar responses

56

TECHNICAL YEARBOOK 2023