Analysis of Soil Fertility and Heavy Metals Contamination on Post- Mining Laterite Nickel Southeast Sulawesi, Indonesia

The aim of this study was to assess soil fertility and heavy metal contamination in soil on reclaimed land in two sample areas. Area R1, trees are difficult to grow and R2, trees can grow. This investigation was conducted to reveal the level of soil fertility, concentration and enrichment of various heavy metals in contaminated soil. Twenty-two samples, twelve sampling positions in R1 and ten sampling positions in R2. Inductive study combined ICP-MS (Inductively Coupled Plasma Mass Spectrometry) and ICP-OES (Inductively Coupled Plasma-Optically Emission Spectrometry) methodologies to determine the concentration levels of Cu, Pb, Zn, Ni, Co, Mn, As, Cd and Cr. A total of four R1 soil samples and four R2 soil samples were measured by XRD to determine the mineralogy and study the flame emission photometry method, extraction and Walkley-Black to determine the soil physicochemistry: texture, pH, K + , Na + , Ca, Mg, Available Phospor, K, organic carbon, base saturation and cation exchange capacity (CEC). Correlation coefficient analysis and cluster analysis, coupled with principal component analysis, were used to analyze the data and to identify possible sources of these heavy metals. Overall, the levels of heavy metal enrichment are arranged in the following EF order: Cr R1 < Cr R2 ; Mn R1 > Mn R2; Zn R1= Zn R2. Heavy metals Mn, Cr, Co, Ni generally exceed moderate pollution and even strong pollution (2 < Igeo < 3; 3 < Igeo < 4; 5 < Igeo), and Zn, Cu low to moderate pollution levels (0 < Igeo < 1; 1 < Igeo < 2), but Pb, Cd, As low pollution levels (0 < Igeo). The results showed that the difficulty of tree growth in all places in R1 was indicated by the physicochemical properties of soil texture and CEC which were in line with mineralogy in influencing soil fertility and even distribution of heavy metals. Compared to R2, the presence of tree growth was related to a positive correlation between soil texture and organic carbon which played an important role in fertilizing the soil and mineralogy support to control the uneven distribution of heavy metals.