Broad nutrition resources are outlined in the Agronomists Toolkit. Specific nutrient categories are listed below:



Constraint – Manganese 

Plant use

  • Manganese is a micronutrient

  • Manganese is a catalyst in plant-growth processes, is essential for rapid germination, and plays a role in enzyme systems

  • As canola has an extensive network of fine feeder roots that can secrete organic acids that enhance nutrient uptake, deficiency is not common


  • The whole plant becomes paler
  • Younger leaves develop interveinal paleness to yellowing, but veins remain green
  • Heavy lime applications can induce deficiency in the year of application


  • Yield penalty is very rare


There is no reliable soil test for manganese. Soil test manganese is generally poorly related to grain yield increase so that critical concentrations can't be determined. Application of magnesium sulphate and maintenance of soil pH below 7 will act to increase the available manganese in the soil.


Links and Resources

AOF - Canola nutrition. Manganese

Page 6 of 8. Information on manganese deficiency.

CSIRO - Acid soils- A ticking time bomb. Manganese

2 page PDF. Lost production, farming and acidity, toxic metals, improved plants, manganese tolerance, and future prospects. Published 2005.

DAFWA - Diagnosing manganese deficiency in canola

Introduction, what to look for in plant and paddock, where does it occur, and how can it be monitored. page last updated 2014.

DEPI VIC - What nutrients do plants require? Manganese

Section 6.4.4. Manganese use by plants, deficiency symptoms, toxicity symptoms, effects on animal health, and control options. Page last updated 2013.

DPI NSW - Soil acidity and liming. Manganese

Impacts of soil acidity, recognising soil acidity, causes, reduction in production, reducing the impact, management, estimating rates of soil acidification, and further information. Specific information on manganese on pages 11-14 of 24.

GRDC - Best Practice Management Guide. Manganese

Page 39 of 92. Brief information on manganese toxicity.

GRDC - Micronutrients and trace elements. Manganese

4 page PDF. Key points, general introduction, crop demand and uptake, tissue testing, soil testing, visual symptoms, soilmapp, effects of soil type, and treatment. Page 2 has specific information on manganese. Published 2013.

IPNI - Canola 4R Guide. Manganese

Page 20 of 21. Description, impact, contributing factors, and management for both deficiency and toxicity. Published 2013.