Does zinc toxicity exist in soils, or is there an upper limit to zinc use in soils?
Zinc, in common with the other plant micronutrients, can limit growth when it is present both in inadequately low concentrations and also in excessive concentrations, due to deficiency and toxicity, respectively. So, while excess zinc can be toxic to plants, just as in the case of zinc deficiency, plants vary widely in their tolerance to zinc toxicity. Although zinc toxicities are possible, they are not likely to be important for most agricultural land anywhere in the world. Apart from areas polluted by industry and some fields receiving excess zinc – rich sludges or manures, most soils will mainly have either normal (sufficient) or deficient levels of zinc. For a more detailed discussion on zinc toxicity in plants, please refer to Section 2.5 of Professor Brian Alloway’s book in our publications section titled: Zinc in Soils and Crop Nutrition. To view a Table of Contents of this publication, and to download individual chapters, click here.
