Diagnosing nitrogen deficiency in wheat

Nitrogen deficiency is the most common nutrient deficiency in wheat especially during cold, wet conditions and in well-drained soils in high rainfall areas.

Deficient plants are smaller with yellow leaves and fewer tillers
Reddened stems occur on some varieties
Nitrogen deficiency on unburnt header row

What to look for


  • Light green to yellow plants particularly on sandy soils or unburnt header or swathe rows.
  • Double sown areas have less symptoms if nitrogen fertiliser was applied at seeding.


  • Plants are pale green with reduced bulkand fewer tillers.
  • Symptoms first occur on oldest leaf, which becomes paler than the others with marked yellowing starting at the tip and gradually merging into light green.
  • Other leaves start to yellow and oldest leaves change from yellow to almost white.
  • Leaves may not die for some time.
  • Stems may be pale pink.
  • Nitrogen deficient plants develop more slowly than healthy plants, but maturity is not greatly delayed.
  • Reduced grain yield and protein levels.

What else could it be

Condition Similarities Differences
Diagnosing waterlogging in cereals Pale plants with oldest leaves most affected Root browning or lack of feeder roots and wet soil
Diagnosing potassium deficiency in wheat Pale plants with oldest leaves most affected Differences include more marked leaf tip death and contrast between yellow and green sections of potassium deficient plants. Tillering is less affected.
Diagnosing molybdenum deficiency in cereals Pale poorly tillered plants Molybdenum deficiency affects the middle leaves first and cause white heads, shrivelled grain and delayed maturity

Where does it occur?

Soil type
Soil type
Wet conditions
Wet conditions
  • Nitrogen deficiency can occur on most WA soils but is most common in the following situations.
  • In cold, wet conditions that slow nitrogen mineralisation and the uptake of nitrogen.
  • Soils with very low organic matter.
  • High rainfall on well-drained soils and soils with sandplain traffic pans can result in nitrogen leaching.

Management strategies

Spraying foliar
Spraying foliar
Soil application
Soil application
  • Nitrogen fertiliser or foliar spray.
  • There is a risk of volatilisation loss from urea or (ammonium sources of nitrogen on alkaline soils) when topdressesd on dry soils in dewy conditions. Losses rarely exceed 3% per day

How can it be monitored?

Tissue test
Tissue test
Soil test
Soil test
  • Use whole-top plant test to diagnose suspected nitrogen deficiency and compare paired good/poor plant samples where possible. Critical N concentration decreases as the plant ages/matures. Critical N value for whole shoots is about 5% at tillering decreasing to 1.5% at the boot stage.
  • Nitrogen soil testing is of limited value for most soils unless used in conjunction with other rotational, soil type and rainfall information.
  • Tools such as the Select Your Nitrogen calculator that combines 0 -10 centimetres soil test organic carbon, soil type and legume history are valuable for calculating nitrogen fertiliser requirement.

Where to go for expert help

Craig Scanlan
+61 (0)8 9690 2174
DDLS Seed Testing and Certification
+61 (0)8 9368 3721
Page last updated: Monday, 27 February 2017 - 12:35pm