Kendala sifat-sifat kimia dan fisik tanah terhadap pertumbuhan revegetasi di lahan bekas tambang nikel

The chemical and physical properties of top soil as a planting medium in ex-mining land reclamation areas play an important role in supporting successful revegetation. This study aims to study the physical and chemical properties of top soil in the reclamation area of a former nickel mine which is thought to be a factor inhibiting plant growth. Undisturbed and disturbed soil samples were taken at depths of 0-30 cm and 30-60 cm in the reclamation area and in the natural environment. Soil sample analysis includes: pH (H2O and KCl 1N extract), organic-C, total-N, available-P and total-P potential, cation exchange capacity (CEC), base saturation, micro nutrients, texture, bulk density, permeability, and pF curve. Soil biological properties are represented by the number of mycorrhiza parameters. Several plant leaf samples were also taken for analysis of N P K Ca Mg S and micronutrient content. The results of the analysis of soil and plant leaves were compared with the results of analysis of soil and plant leaves taken outside the mining area where the soil developed from different parent materials. The results of the analysis showed that the soil in the reclamation area has several anomalous properties that cause the growth of revegetation plants to be hampered: the soil pH is classified as slightly acidic to neutral, but has a variable charge depending on pH with a positive net charge, very low soil CEC, very low exch.-K, exch.-Ca/Mg ratio less than 1, levels of elements that are potentially toxic to plants are quite high, and the distribution of soil particles is dominated by silt size. These properties are closely related to iron oxides in the soil as a result of chemical weathering of ferromagnesian minerals contained in ultramafic rocks which are the parent material of the soil.