Handbook for Irrigation of Wine Grapes in South Africa
Chapter 3
90 coarse sand 2.0 - 0.5 mm medium sand 0.5 - 0.25 mm fine + very fine sand 0.25 mm - 0.05 mm 10 A 100
coarse sand 2.0 - 0.5 mm medium sand 0.5 - 0.25 mm fine + very fine sand 0.25 mm - 0.05 mm 10
100
90
20
80
20
80
fine sand
fine sand
30
70
30
70
40
60
40
60
50
0
50
50
60
40
60
medium sand
coarse sand
medium sand
coarse sand
70
70
30
80
80
20
90
10
90
100
100
50 70 60 40 30
10 20
100
90
50 80 70 60 40 30
10 20
% COARSE SAND
% COARSE SAND
B
sand 2.0 - 0.05 mm silt 0.05 - 0.002 mm clay <0.002 mm
100
sand 2.0 silt 0.05 clay
100
10
90
10
90
20
80
20
80
30
70
clay
30
70
40
60
clay
4
60
50
50
silty clay sandy clay loam
sandy clay sandy clay loam
40
60
50
silty clay sandy loa
clay loam
sandy clay sandy clay loam
40
70
30
clay loam
80
20
loam
30
silt loam
sandy loam
10
90
20
loam
sand pure sand
loamy sand
silt
silt l
sandy loam 100
10
sand pure sand
100
90
50 80 70 60 40 30
loamy sand 10 20
% SAND
100
90
50 80 70 60 40 30
FIGURE 3.1. Soil texture triangles used in South Africa to determine (A) the sand grade, as well as (B) the soil textural class (Soil Classification Working Group, 1991). % SAND
IRRIGATION OF WINE GRAPES 55
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