Wilcox diagram

Classes/Ranges and quality

Classes

Range

Quality

Conductivity

C1

100 - 200

Excellent

C2

250 - 750

Good

C3

750 - 2250

Doubtful

C4 - C5

>2250

Unsuitable

SAR

S1

<10

Excellent

S2

10 - 18

Good

S3

19 - 26

Doubtful/Fairly

S4 - S5

>26

Unsuitable