Relationships between trace element contents and other soil variables in some Papua New Guinea soils as shown by regression analysis

Abstract

Multiple linear regression has been used to examine the relationships between total trace element contents and a number of other soil variables in horizons of six texture-contrast soils from Papua-New Guinea. The results indicate that the trace elements can be divided into three groups on the basis of both regression analyses and profile distribution: namely copper, zinc, and nickel; cobalt and manganese; and chromium. With the copper concentration in the soil as the dependent variable a regression equation having an index of determination (R2) of 0.89 was obtained containing as major independent variables copper concentration in the parent material and percentage clay of the soil horizon. Zinc and nickel showed a similar relationship to percentage clay as copper but the major variability of these elements remains unexplained. Manganese and cobalt were found to be mainly related to the presence of a fluctuating water table occurring in three of the six profiles (R2 = 0.59), while chromium was principally related to the percentages of the 50-75, 150-210, and 420-1200 µ sand fractions (R2 = 0.84).