The effect of pH on acute copper toxicity to barely (Hordeum vulgare)

Soil pH is one of the important influencing factors of copper (Cu) speciation and toxicity. The Cu acute toxicity to barley (Hordeum vulgare) of different pH values were investigated to provide the basis for soil quality criteria and a risk assessment. The results showed that a significant nonlinear correlation between total Cu concentration or dissolved Cu concentration and the percentages of barley root elongation with respect to controls (RE) in the range of pH 4.54-8.03. Increases in pH, EC50 expressed as total Cu linearly increased, but EC50 expressed as dissolved Cu did not significantly change, indicating that the dissolved Cu may be batter than total Cu to evaluation Cu toxicity to terrestrial plants.