Constraints of chemical and physical properties of soil on the growth of revegetation plants on ex-nickel mining land

Abstract

The chemical and physical properties of 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 properties of soils 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 in the reclamation area and the natural environment at depths of 0-30 cm and 30-60 cm. Soil sample analysis includes pH, organic C, total N, available P and potential P reserve, cation exchange capacity (CEC), base saturation, micronutrients, 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 showed that the soil in the reclamation area has several anomalous properties that cause the growth of revegetation plants to be hampered, i.e. the soil pH is slightly acidic to neutral, the CEC is very low due to a positive net charge, the exchangeable Ca/Mg ratio is less than 1, the levels of elements that are potentially toxic to plants are quite high, and the distribution of soil particles is dominated by silty 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.