Effect of aluminum on plant chemical concentrations in some temperate grasses grown in solution culture at low ionic strength

Abstract

The effects of aluminum (Al) on plant chemical concentrations were determined in 28 cultivars from 11 species of temperate grasses. For each cultivar and nutrient (N, P, S, Mg, Ca, K, Mn, Zn, Cu, Fe, B, Al), the relationships between Al activity in the nutrient solution and plant nutrient concentration were determined using polynomial exponential splines. Estimates were made of the nutrient concentration at 0 μM Al and the Al activity (μM) at which relative yield was reduced by 50% (Al_ry50). At A1_ry50 the ^most consistent effect of Al was to decrease Ca and Mg concentrations in the tops by 46% and 27% on average, and to increase B concentrations in the tops by 13% on average. Phosphorus (P) concentrations increased in the roots (except for one experiment) by 39% in response to increasing solution Al. In the Lolium cultivars, Zn and Cu root concentrations increased by 250% and 180% at Al_RY50. Concentrations of Mg and S were higher in the roots of some of the more Al tolerant species tested. High concentrations of Al accumulated on the roots (mean increase from 370 to 3850 μg g^‐1 Al) but not in the tops (mean increase from 38 to 104 μg g^‐1 Al).