Handbook for Irrigation of Wine Grapes in South Africa

Chapter 7

Figure 7.35 Figure 7.35

A

B

FIGURE 7.35. Examples of vigorously growing (A) Triticale and (B) Oats winter cover crops in vineyards.

6 kPa = Field capacity

280

240 220 200 180 160 140 120 100 80 260 Soil water content (mm/120 cm)

Irr.

Irr.

Irr.

Rain = 23.9 mm

Bare soil Growing cover crop Single mulch layer Double mulch layer

Permanent wilting point

8

6 29

27

3

24 1

29 5

10 1 25

Sep

Oct

Nov

Dec

Jan

Feb

Date

FIGURE 7.36. The effect of a growing Rye grass ( Lolium multiflorum ) cover crop on soil water depletion in a flood irrigated Colombar vineyard near Oudtshoorn (redrawn from Van Huyssteen et al ., 1984).

IRRIGATION OF WINE GRAPES 223