REFERENCE SUFFICIENCY RANGES
FIELD CROPS

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Canola

C. O. Plank and M. R. Tucker

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• Critical Values
  
  

  Critical values at 90% relative yield
  N	P	K	Ca	Mg	S	Mn	Fe	B	Cu	Zn
  3.60%	0.37%	2.15%	1.60%	0.10%	0.47%	20 ppm	82 ppm	20 ppm	4 ppm	28 ppm

• Sampling Procedures

  Sample the uppermost recently mature leaf blades prior to flowering.

• Sufficiency Ranges
  
  

  Macronutrients
  N	P	K	Ca	Mg	S
  4.00–6.40%	0.42–0.69%	3.50–5.10%	2.10–3.00%	0.15–0.62%	0.65–0.90%

  
  

  Micronutrients
  Fe	Mn	Zn	Cu	B
  100+ ppm	30–250 ppm	33–49 ppm	5–25 ppm	25–54 ppm

  
  

  Important Ratios

  The calculated N:S ratio should not exceed 16–17 to 1.

• DRIS Norms

  DRIS norms have not been reported at this time.

• Remarks

  The critical values given were calculated from the paper by Haneklaus and Schnug (1991) and based on 90% relative yield. The critical levels were established using the boundary line approach of Walworth and others (1986).

  The lower end of the sufficiency range was calculated at 100% relative yield using the data of Haneklaus and Schnug (1991) and the upper end of the range was established using the data reported by Reuter in Reuter and Robinson (1986).

• References

  Haneklaus S, Schnug E. 1991. Evaluation of the nutritional status of oilseed rape plants by leaf analysis. In: Proceedings of the 8th international rapeseed congress; Saskatoon, Saskatchewan, Canada. p 536–41.

  Reuter DJ. 1986. Temperate and sub-tropical crops. In: Reuter DJ, Robinson JB, editors. Plant analysis: an interpretation manual. Melbourne (Australia): Inkata. p 63–4.

  Walworth JL, Letzsch WS, Sumner ME. 1986. Use of boundary lines in establishing diagnostic norms. Soil Sci Soc Am J 50:123–8.

Electronic Document Prepared by:
Catherine Stokes, Communication Specialist
Agronomic Division of the N.C. Department of Agriculture and Consumer Services. July 2000.