Diagnosing salinity in narrow-leafed lupins

Salinity affects plant growth by reducing the root's ability to extract water from the soil. Salinity damage varies from season to season due to variations in the soil salt concentration. Waterlogging increases salinity damage.

Reduced emergence and smaller plants that die earlier near saline areas
Wilted patch
Older leaves shrivel and die
Roots may look normal before death

Primary salinity

  • Primary salinity refers to soils and landscapes that were saline in their undisturbed state, before agricultural development.
  • Most common are alkaline aeolian morrell-blackbutt loams on the edge of major wheatbelt valleys.

Secondary salinity

  • Secondary salinity refers to soils and landscapes that have become saline since being developed for agriculture.
  • Secondary salinity is caused by salt accumulation in the soil from shallow saline watertables that have developed after land clearing when shallow-rooted crops and pastures replaced deep-rooted perennials.
  • Soils vary but are frequently duplex or heavy textured.
  • Salinity is frequently accompanied by waterlogging in winter, which greatly increases plant damage.

What to look for


  • Symptoms vary with soil salt concentration and severity of waterlogging.
  • Poor crop and weed germination (except salt tolerant species).
  • Patches of apparently water-stressed or prematurely dead plants in areas subject to salinity in spring.
  • Dry topsoils may be crusty possibly with salt crystals on the surface .


  • Seeds swell but don't germinate or emerge, or seedlings die after emergence, particularly in drying soil.
  • Wilted and dying plants in spring.
  • Roots may appear to be normal, but may be shallow and rot quickly after plant death.

What else could it be

Condition Similarities Differences
Diagnosing spring drought in narrow-leafed lupins Reduced yield, early death. More general distribution.
Diagnosing hostile subsoil in narrow-leafed lupins Reduced yield, early death. Soil type specific but sot saline.

Management strategies

  • Avoid growing narrow-leafed lupins on these soils.

How can it be monitored?

  • The salinity status of a soil can be assessed from indicator plants, measuring the salt concentration in soil samples or with electromagnetic-induction instruments or by measuring the depth to a saline watertable.
Page last updated: Thursday, 5 February 2015 - 3:12pm