highly significantp < 0.001
In comparison, there were highly significant and positive correlations between total P and MgCl 2 -P (r = 0.92, p < 0.001, Fig. 3a ) and HCl-P (r = 0.91, p < 0.001, Fig. 3d ) at high P levels (total P > 3.5 mg g −1 ).
In comparison, there were highly significant and positive correlations between total P and MgCl 2 -P (r = 0.92, p < 0.001, Fig. 3a ) and HCl-P (r = 0.91, p < 0.001, Fig. 3d ) at high P levels (total P > 3.5 mg g −1 ).