Interactive effect of biochar and compost with Poaceae and Fabaceae plants on remediation of total petroleum hydrocarbons in crude oil contaminated soil

The current study was dedicated to finding the effect of soil amendments (biochar and compost) on plants belonging to Poaceae and Fabaceae families. Plants selected for the phytoremediation experiment included wheat (Triticum aestivum), maize (Zea mays), white clover (Trifolium repens), alfalfa (Medicago sativa), and ryegrass (Lolium multiflorum). The physiological and microbial parameters of plants and soil were affected negatively by the 4 % TPHs soil contamination. The studied physiological parameters were fresh and dried biomass, root and shoot length, and chlorophyll content. Microbial parameters included root and shoot endophytic count. Soil parameters included rhizospheric CFUs and residual TPHs. Biochar with wheat, maize, and ryegrass (Fabaceae family) and compost with white clover and alfalfa (Poaceae family) improved plant growth parameters and showed better phytoremediation of TPHs. Among different plants, the highest TPH removal (68.5 %) was demonstrated by ryegrass with compost, followed by white clover with biochar (68 %). Without any soil amendment, ryegrass and alfalfa showed 59.55 and 35.21 % degradation of TPHs, respectively. Biochar and compost alone removed 27.24 % and 6.01 % TPHs, respectively. The interactive effect of soil amendment and plant type was also noted for studied parameters and TPHs degradation.

Automated summary

The study investigated the impact of soil amendments (biochar and compost) on phytoremediation of TPHs by plants from Poaceae and Fabaceae families. Results showed that biochar and compost improved plant growth and TPH removal, with ryegrass and white clover exhibiting the highest removal rates. Different plant species responded differently to soil amendments in terms of TPH degradation.