A biotic ligand model predicting acute copper toxicity for barley (Hordeum vulgare): Influence of calcium, magnesium, sodium, potassium and pH

► We examine the effects of some cations and pH on the toxicity of Cu to barley. ► Increasing activity of Mg2+ and Ca2+ will decrease Cu toxicity. ► The increase of Cu toxicity with increasing pH is due to change of Cu species. ► We model Cu toxicity based on the biotic ligand model (BLM) concept. ► The developed BLM demonstrate good performances in predicting Cu toxicity.