Soil Chemical and Physical Properties of Reforested Mined Land at Different Ages After Reclamation

Fast-growing legume trees are usually used for revegetation of the mined areas because legumes can fix nitrogen due to their symbiosis with rhizobia. The objective of this study was to analyze the changes in soil properties in reclaimed mined soil after 3, 6, and 9 years of revegetation with sengon (Falcataria moluccana) in North Bengkulu, Indonesia. The fieldwork was conducted from August through October 2023. Soil sampling was done in each site at two soil depths, 0–20 cm and 20–40 cm. Biomass of trees, poles, understory, and litter was measured for each vegetation age. Soil chemical and physical properties measured were pH, organic C, P, N, Ca, K, CEC, FC, BD, and texture (percentage of sand, silt, and clay). The statistical analyses conducted were regression, ANOVA, and LSD. Carbon content (C) and Cation Exchange Capacity (CEC) differed significantly among vegetation ages and soil depths. The bulk density of the soil in 3-year-old vegetation was significantly higher than that in other ages, but there was no significant difference between 9 and 6-year-old vegetation. Total tree, pole, and litter biomass increased with age. Litter biomass was positively correlated with the organic carbon, CEC, and Ca. Soil properties improved over time, indicating the effect of vegetation on soil.