Residual Effect of Copper and Zinc from Fertilizers on Plant Concentration, Phytotoxicity, and Crop Yield Response

Abstract

To avoid toxicity resulting in reduced crop yields and/or phytotoxic symptoms on the foliage, information on the residual effect of micronutrient fertilization after periods of application is desirable. This article includes discussion on the micronutrients copper (Cu) and zinc (Zn), because they are essential and are of concern from plant and animal standpoints. In general, no detrimental effects in yield reduction or phytotoxicity were noted from Cu applications of up to 50 kg Cu ha⁻¹ to barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.). Barley was an exception where 50 kg Cu ha⁻¹ decreased yield by about 12% in the first‐year crop. The Cu levels in plants did not exceed 9 mg kg⁻¹. Studies showed that Zn applications of 50 kg ha⁻¹ for 2 years in succession and the resulting crop tissue Zn levels as high as 105 mg kg⁻¹ did not cause any phytotoxicity in cereals. The results of this study suggest that cereals can tolerate high levels of Cu and Zn.

Keywords:

• Cereals
• eastern Canada
• Podzol soils
• soil Cu and Zn