Soil Salinity Calculator
Soil salinity class and crop guidance from ECe.
What it does
Salt shadows every irrigated field: invisible in the bag, brutal in the root zone as water leaves and salts stay. ECe grades the load into classes with matching crop advice.
The tool above takes saturated extract EC in dS/m. It returns the salinity class, crop guidance, and leaching need.
The default 6.5 reads moderately saline for tolerant crops only with leaching. The 1.2 case reads non saline for most crops, and 20 reads very strongly saline.
Salinity laboratory classification draws the bands at 2, 4, 8, and 16 with crop tolerance falling each step. FAO soils guidance repeats the same classes for global surveys.
Leach deliberately or not at all: extra water past field capacity drains salts only where drainage exists. Sodic ground needs gypsum plus drainage beyond this page.
How to use
- Type ECe in dS/m.
- Read the class first.
- Read crop guidance beside it.
- Read leaching need last.
- Confirm odd readings by lab.
- Match crops to the class.
Formula
- ECe
- Saturated extract EC in dS/m.
- class
- Salinity class name.
USDA Salinity Laboratory classification bands soils by saturated extract EC with the same 2/4/8/16 breaks. FAO soils guidance mirrors the classes with matching crop tolerance notes. Leaching guidance follows: extra water below the root zone only where classes demand it.
Worked example
Example: 6.5 dS/m sample
Default: ECe 6.5 dS/m.
- Sample: ECe 6.5 dS/m.
- Bands: under 2, 4, 8, 16 split classes.
- Class: 4 to 8 reads moderately saline.
- Crops: tolerant crops only past 4.
- Leach: extra water required.
- Tool shows Moderately saline, Tolerant crops only, Leach with extra water.
Reference table
| ECe | Class | Crops |
|---|---|---|
| Under 2 | Non saline | Most crops fine |
| 2 to 4 | Slightly saline | Sensitive crops suffer |
| 4 to 8 | Moderately saline | Tolerant crops only |
| 8 to 16 | Strongly saline | Halophytes or reclaim |
| Over 16 | Very strongly saline | Reclaim first |
Limits
- EC screening, not full analysis.
- Sodium structure unread here.
- Drainage assumed for leaching.
- Lab confirms odd readings.
Common mistakes
- Reading EC without ECe method.
- Leaching undrained ground.
- Planting sensitive crops blind.
- Confusing saline with sodic.
- One sample for whole farms.
Try it yourself
Quick checks. Answers sit tucked under each question.
ECe 1.2?
Non saline, most crops fine, no leaching needed.
ECe 20?
Very strongly saline: halophytes or reclaim, leach with extra water.
ECe minus 1?
Negative salt is unphysical: enter ECe from 0 up.
Questions
Class bands?
Under 2 non, 2 to 4 slight, 4 to 8 moderate, 8 to 16 strong, over 16 very strong saline.
Crop tolerance?
Beans and carrots fade early; wheat, cotton, and beets tolerate more. Halophytes own the top.
Leaching?
Extra low salt water past field capacity, draining salts below roots. Test after.
ECe meaning?
Saturated paste extract of a soil sample. Field meters estimate; labs confirm.
Saline or sodic?
Yes, sodium wrecks structure while salinity stresses water uptake. Gypsum plus drainage treats sodic ground.
Irrigation effects?
Drip and mulch cut surface buildup; flood and sprinkler swing wider.