Response of honelocust (Gleditsia triacanthos L.) to soil solution aluminium

Honeylocust (Gleditsia triacanthos L.) seedlings were grown for 72 days in soil from a BC horizon of a Spodosol altered by adding four levels of AlCl₃. Saturated paste extracts from controls to the highest AlCl₃ treatment contained, respectively, 85 to 831 M Al, 834 to 163 M Ca and 316 to 35 M Mg and had a pH of 4.4 to 4.0 Leaf, stem, and root concentrations of Al and P increased while those of Mg, Ca, and Zn decreased with increasing levels of Al. Growth decreased as Al, Al/Ca, and Al/Mg ratios in the extract increased. Growth was negatively related to tissue concentrations of Al, P, and Zn and positively related to tissue Mg and Ca. Growth was more closely correlated to elemental concentrations in the saturated paste extracts than in the SrCl₂ extracts (1 part 0.01M SrCl₂: 1 part moist soil).The research was supported by EPRI grant RD 2365-01 and by the University of Minesota College of Forestry and Minnesota Agricultural Experiment Station Project 074; listed as Minnesota Agricultural Experiment Station Scientific Series Paper.