Soil-site characteristics

Unit

Rating

Highly

suitable

S1

Moderately suitable

S2

Marginally suitable

S3

Not suitable

N

Climatic regime

Mean temperature in growing season

˚C

26 - 30

31 - 34

24 - 25

35 - 40

20 - 23

>40

<20

Mean max. temp. in growing season

˚C

31 - 33

33 - 35

>35

-

Mean max. temp. in growing season

˚C

22 - 18

18 - 15

<15

-

Mean RH in growing season

%

50 - 70

50 - 40

<40

-

Total rainfall

mm

650 - 850

>850

650 - 550

450 - 550

<450

Rainfall in growing season

mm

500 - 700

400 - 500

300 - 400

<300

Land quality

Land characteristics

Moisture availability

Length of growing period

Days

120 - 150

120 - 90

<90

-

AWC

mm∙m⁻¹

150 - 200

100 - 150

50 - 100

<50

Oxygen availability to roots

Soil drainage

Class

Well to moderate

Imperfect

Poor/Excessive

Very poor

Water logging in growing season

Days

2 - 3

3 - 4

4 - 5

>5

Nutrient availability

Texture

Class

c, cl, sicl, sc

l, sil, sic

sl, ls

s, fragmental skeletal

pH

1:2.5

6.0 - 8.0

5.5 - 5.9

8.1 - 8.5

<5.5

8.6 - 9.0

>9.0

CEC

cmol (p+)/kg

30 - 20

20 - 10

<10

BS

%

80 - 50

50 - 35

<35

CaCO₃ in root zone

%

5 - 10

10 - 25

>25

OC

%

0.50 - 0.75

0.50 - 0.20

<0.20

Rooting conditions

Effective soil depth

cm

100 - 75

50 - 75

30 - 50

<30

Stoniness

%

5 - 15

15 - 30

30 - 60

>60

Coarse fragments

Vol (%)

5 - 15

15 - 40

40 - 75

>75

Soil toxicity

Salinity (EC saturation extract)

dS∙m⁻¹

2 - 4

4 - 8

8 - 10

>10

Sodicity (ESP)

%

5 - 8

8 - 10

10 - 15

>15

Erosion hazard

Slope

%

2 - 3

3 - 8

8 - 15

>15