Fig. 1From: Subsoils—a sink for excess fertilizer P but a minor contribution to P plant nutrition: evidence from long-term fertilization trials Stock of labile (Resin-P, NaHCO3–Pi,o), moderately labile (NaOH–Pi,o), and stable (H2SO4–Pt and Residual-Pt) P fractions. Samples were obtained from the long-term experimental sites Dahlem, Freising Dürnast, and Bad Lauchstädt at different soil depths. Error bars represent standard deviations of the mean (n = 3)Back to article page