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Soda saline-alkali: alkali and salt are not the same thing

Slick, hard, high pH is sodium. White powder is salt.

Salty-alkali land
Speed
  1. Soil feels soapy and sticky, pH often above 8.5, structure gone, poor emergence.
  2. A thick frost is not required.
  3. Salty soil is high EC, pH not always very high; alkali soil is high pH and high sodium.
  4. Lime is for acid; lime on alkali soil makes it more alkali.
  5. Don’t gypsum a chloride salt soil by default; don’t gypsum an acid soil.
  6. Agricultural gypsum: Follow a soil test. Commonly tens to a hundred-plus kg per mu. Must be tested; pair it with washing salt
  7. Name what you see before you feed.
  8. If leaves, roots and the surface disagree, stop.

What you see in the field

Soil feels soapy and sticky, pH often above 8.5, structure gone, poor emergence. A thick frost is not required.Squat on the whitest, worst strip and scrape the crust. Compare with a neighbour that is still green. White crust plus scorched margins count; wilt without a crust may just be drought. Note whether the ditch actually runs.

A sketch. Do not fertilise from the picture alone.

Tap to enlarge. The caption says what to photograph. Missing field photos are marked as to-be-added.

Why it looks like this

The field looks like this because the root cannot take water or nutrients the usual way. Fix the soil condition first — drainage, salt, acidity, compaction or a salt of fertiliser — then a thin feed. Rates live in the range on this page; confirm with a local station and the label.

Easy to mix up

  • Looks like “Ordinary salty soil”

    Salty soil is high EC, pH not always very high; alkali soil is high pH and high sodium.

  • Looks like “Acid soil”

    Lime is for acid; lime on alkali soil makes it more alkali.

Do this / don’t do that

  1. 1Soil feels soapy and sticky, pH often above 8.5, structure gone, poor emergence. A thick frost is not required.
  2. 2Confirm sodicity, then gypsum, with drainage, organic matter and tolerant crops. Small patch.
  3. 3Don’t gypsum a chloride salt soil by default. Use the range on this page only as a range. Confirm with a local station and the product label.

Don’t do this first

  • Don’t gypsum a chloride salt soil by default; don’t gypsum an acid soil.

Rate range

Agricultural gypsum

Follow a soil test. Commonly tens to a hundred-plus kg per mu

Must be tested; pair it with washing salt.

Drainage

Sodium only washes if there is an outlet

No drain, no large rate.

These are ranges. Confirm with your local extension station and the product label.

pH

Alkali or not

Sodic alkali soil often above 8.5.

ESP / sodium

Whether structure is broken

Only when it is high do you think about gypsum.

When you see Soil feels soapy and sticky, test. Write the field and the date on the bag.

Lesson video

2026-03-15 · Li Zeyu · For learning. Serious damage: local agronomist or a soil test.

For learning only. Fertiliser and pesticide decisions need a local agronomist and a soil test.

Not sure? Photograph the field to identify the problem