Path coefficient analysis of zinc and boron adsorption in soils

Path coefficient analysis, a statistical technique that differentiates betw een correlation and causation, was employed to describe zinc (Zn) and boron (B) adsorption on soils. A path analysis model evaluating the effect of cl ay, free calcium carbonate (CaCO3), organic carbon (OC) and cation exchange capacity (CEC) on Zn and B adsorption as measured by Langmuir adsorption m axima 'b' values in surface (0-25 cm) soils possessing varied physico-chemi cal and mineralogical characteristics was developed. Correlation analysis s howed the dominant role of clay and OC, and clay alone in affecting B and Z n adsorption, respectively, while path analysis described the significant d irect effect of clay and indirect effect of CEC via clay on Zn adsorption a nd the significant direct effect of CEC and OC and indirect effect off clay via CEC on B adsorption. Path analysis model constructed for CEC exhibited the significant direct contribution made by clay towards CEC in both the e xperimental soils, thus, revealing the relationship between CEC and adsorpt ion of Zn and B.