Ecological restoration of oil-impacted areas in restinga: Soil management strategies and native species planting techniques

Abstract

Exploitation of natural resources has decreased soil fertility and increased compaction. These effects hinder plant establishment. In this context, information on strategies for restoring degraded areas at the bases of deactivated oil wells remains scarce. This study aimed to evaluate the growth of the native species Psidium cattleyanum and Inga laurina, as well as the chemical attributes of the soil in a restinga area located at the base of a deactivated oil well. Three planting strategies were tested (control, CT; fertilisation in planting holes, WF; and use of native bromeliads, BR) in two types of substrates (sandy, with removal of the clay layer; and clayey, with preservation of the clay layer). The variables analysed included plant morphological attributes and soil chemical composition. The results showed that the clayey substrate, after decompaction, improved I. laurina performance, especially under the WF and BR treatments, whereas P. cattleyanum exhibited greater growth in sandy soil, indicating edaphic adaptation and a positive response to fertilisation under low-fertility conditions. Fertilisation increased the levels of organic matter, phosphorus, potassium, magnesium, and cation exchange capacity, which were positively reflected in the plant biomass. Principal component analysis highlighted the influence of the WF and BR techniques, which were associated with improved soil chemical attributes and plant growth. Therefore, P. cattleyanum and I. laurina are recommended for revegetation projects in degraded restinga areas on both sandy and clayey substrates. Maintaining the clay layer is agronomically advantageous, making it a viable option for deactivated oil wells.