DESCRIPTION OF SOME SOIL AGROCHEMICAL CHARACTERISTICS THROUGH PCA ANALYSIS

Abstract

The study evaluated how certain agrochemical indices, used in soil characterization, were classified. The study area, where the soil samples came from, was in the "Padurea Cenad" Protected Area, Timis County, Romania. The considered agrochemical indices resulted from soil analysis for agricultural land and forest land. The agrochemical indices were represented by soil reaction (pH), the content of some macroelements (Nt, P, K, Ca, Mg), microelements (Fe, Mn, Cu, Zn), and heavy metals (Cr, Ni, Pb). The soil reaction was considered with each group of elements in the analysis. According to the PCA analysis, in the case of macroelements, pH, Nt, K, Ca were grouped in PC1, and P and Mg were grouped in PC2. In the case of microelements, pH, Mn, Zn were grouped in PC1, and Cu and Fe were grouped in PC2. In the case of heavy metals, all elements were grouped in PC1. The soil reaction (pH) showed negative action in relation to macroelements (r = -0.999), and in relation to heavy metals (r = -0.972), and positive action in relation to microelements (r = 0.847). Negative action was also recorded in the case of Ca (r = -0.970). In the case of macroelements, Mg showed a strong action (r = 0.770), and the other elements showed a very strong action (r > 0.900). In the case of microelements, pH and Fe showed a strong action (r = 0.847; r = 0.877), and the other elements showed a very strong action (r > 0.900). In the case of heavy metals, Cr showed a weak action (r = 0.576), and the other elements showed a very strong action (r > 0.900). In all three analyzed groups, the results showed statistical certainty (p < 0.001).