JEQ -- Calhoun et al. 31 (1): 38 Figure IG5

Click on image to view larger version.

Fig. 5. Changes over time for (a) the original concentration of Bray-1 phosphorus in the Ap horizon (P_or) and the difference between means of the current concentration of Bray-1 phosphorus in the Ap horizon (P_cu) and P_o; (b) relative change in P_or compared with fertilizer P sales.