Influence of soilpH on availability of cadmium, copper, and zinc in three North Dakota soils

The pH of three surface soils were adjusted up and/or down by adding various amounts of dilute hydrochloric acid (HCl) and sodium hydroxide (NaOH) and equilibrated at room temperature (25;Lowering soil pH increased DTPA extractable Cd and Zn. Raising soil pH resulted in either a slight increase or no change in DTPA extractable Cd and Zn. Labile Cd and Zn extracted by 0.01 M calcium chloride (CaCl;The DTPA procedure gave the best overall correlation with Cd and Zn concentrations in oat. Considering the plant data might be influenced by other factors, the chelating ion exchange membrane and dilute CaCl...