Evaluation of Physical and Chemical Soil Quality to Support Post–Oil Mining Land Rehabilitation in PT. Bumi Siak Pusako

Abstract

Oil and gas mining activities conducted within conservation areas require careful post-mining land management to ensure the recovery of ecological functions. The Zamrud Oil Field operated by PT Bumi Siak Pusako is located within the buffer and utilization zones of Zamrud National Park, Riau Province, where post-mining land degradation has become a critical environmental concern. This study aimed to evaluate the physical and chemical properties of soils in post–oil mining areas as a basis for formulating sustainable land rehabilitation and environmental management strategies.

The evaluation was conducted through field surveys and purposive soil sampling at inactive oil wells, representing two land conditions: initial condition (pre-mining reference) and production condition (post-mining). Soil physical parameters analyzed included soil texture, bulk density, particle density, and total porosity, while chemical parameters comprised soil pH, organic carbon, total nitrogen, C/N ratio, available and potential phosphorus, exchangeable potassium, base cations, and cation exchange capacity. Laboratory results were analyzed descriptively by comparing soil conditions between the two land conditions.

The results indicated that post–oil mining areas experienced a decline in soil quality, characterized by increased soil compaction, reduced porosity, low organic matter content, and limited nutrient availability. Although soil pH in production areas tended to increase due to the influence of mineral materials, this change was not accompanied by improvements in soil fertility. These conditions limit soil functionality as a growing medium and constrain natural vegetation recovery. The findings highlight the need for integrated soil rehabilitation measures, including organic matter enrichment and phytoremediation, to support sustainable land management in post–oil mining areas within conservation zones.