Efficiency of Elephant Grass (Cenchrus purpureus) as Bioaccumulator Plant and Soil Weathering Enhancer

The increasing challenges of environmental degradation, soil erosion, and climate change have driven interest in sustainable solutions like enhanced weathering (EW) and phytoremediation. Elephant Grass (Cenchrus purpureus), a fast-growing perennial species, shows promise as a bioaccumulator and agent for soil weathering. This study assessed the potential of C. purpureus to improve soil quality through heavy metal (HM) uptake and EW facilitation. A 60-day greenhouse pot experiment at Jackson State University evaluated plant performance in soils amended with metabasalt rock powder at 1:1 and 2:1 rock-to-soil ratios. Biomass, growth, and HM concentrations in roots and shoots were measured via ICP-MS after wet digestion. Soil pH and magnesium (Mg) release were also monitored to assess weathering and carbon drawdown. Results showed that C. purpureus accumulated more HMs in roots at higher amendment levels, while at lower levels, metals like As, Cd, and Cr were more translocated to shoots, enhancing phytoextraction potential. High treatment favored Fe and Al uptake, possibly reducing toxic metal accumulation in edible parts. Notably, C. purpureus contributed to the weathering of 38% of metabasalt rock, leading to a 42% increase in Mg release. With high biomass, HM tolerance, and weathering capacity, C. purpureus offers a sustainable strategy for soil remediation, improved soil health, and potential support for renewable energy systems.