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19
Recommended EC Value (mS/cm)
SME
a
1 to 2
b
Pour thru
Poinsettia during
weeks 2
-
12.
2.0
-
3.0
0.85
-
1.25
2.8
-
4.1
Pansies during
active growth.
0.25
-
1.5
0.1
-
0.6
0.35
-
2.1
Geraniumus during
active growth.
1.6
-
2.4
0.65
-
1.0
2.2
-
3.3
Comparison of substrate tests for various EC sam-
pling methods. (Calvins, Whipker, and Fonteno,
North Carolina State University).
a
saturated media extract
b
1 part soil to 2 parts water
Appendix 2
Classification of
Irrigation Water
Excellent
EC < 0.25 mS/cm
Good
0.25 mS/cm < EC < 0.75 mS/cm
Permissible
0.75 mS/cm < EC < 2.0 mS/cm
Doubtful
2.0 mS/cm < EC < 3.0 mS/cm
Unsuitable
EC > 3.0 mS/cm
Categories of irrigation water quality based on elec-
trical conductivity. [Wilcox L.V. (1948) The Quality of
Water for Irrigation Use, USDA Technical Bulletin
962]