Information on leaching intensity among calcareous soils which are extended in arid, semiarid and Mediterranean regions is important for various environmental and agricultural applications. Referring to the chemical basis of parker, ([(Na)a/0.35]+[(Mg)a/0.9]+[(K)a/0.25]+[(Ca)a/0.7])×100, and CaO/ZrO2 indexes each of them is most useful to investigate a different stage of elemental movement and hence leaching intensity throughout calcareous soils profile. In an attempt to take advantage of the two indexes together; a two dimensional coordination system where axes were CaO/ZrO2 and Parker indexes was applied to two groups of calcareous soils having physico-chemical and morphological evidences of being developed under different leaching intensities from western Iran. From the relationship between the two indexes for the soils of Group1 (α=0.911, n=16) and Group2 (α=0.985, n=15) both significant at α=0.001; distribution pattern of the samples at the coordinate system approved reliability of contribution of the two indexes to differentiate between leaching intensities among calcareous soils. Moreover, relationship between soil color and the two indexes was investigated among the same soil samples. The results approved reliability of L*, a parameter of lightness in CIE color standard system, to estimate Parker and CaO/ZrO2 indexes for the studied calcareous soils.
