Fig. 1. Dependence of log concentration of Zn in plant tissue on the log of (a) effective Zn concentration, C_E, before growth, (b) effective Zn concentration, C_E, after growth, (c) soil solution Zn, before growth, (d) soil solution Zn, after growth, (e) free Zn²⁺ activity, (f) CaCl₂–extracted Zn, (g) Zn E value, and (h) total soil Zn. The quadratic regression equations and regression coefficients are shown.