Sward conducted a study at the University of Arkansas, Fayetteville, and published a thesis assessing the use of biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More and industrial hemp to remediate heavy-metal-contaminated soil. The research focused on soil from the Tar Creek Superfund Site, evaluating hemp’s ability to remove cadmium (Cd), lead (Pb), and zinc (Zn) with the help of biochar amendments.  

Mining activities, such as those in Picher, OK, can lead to significant soil and water contamination with heavy metals. PhytoremediationThis is a technique that uses plants to clean up contaminated soil or water. Biochar can enhance phytoremediation by improving soil conditions and promoting plant growth, allowing plants to absorb and break down pollutants more effectively.   More, using plants to clean up pollutants, offers a more cost-effective and less disruptive alternative to traditional remediation methods. Adding biochar, a carbon-rich substance, can enhance phytoremediation by improving soil properties and immobilizing heavy metals.  

The study found that hemp’s removal of Cd, Pb, and Zn varied across soil contamination levels. Specifically, total Zn uptake was affected by biochar rate in medium- and high-contamination soils, with the largest uptake observed with 10% biochar in high-contamination soil (0.28 mg cm⁻²) and 2% biochar in medium-contamination soil (0.07 mg cm⁻²).  

This study suggests that biochar can enhance hemp’s ability to remediate heavy-metal-contaminated soils, offering a promising strategy for environmental restoration.  

SOURCE: Sward, S. W. (2025). Assessing Biochar and Industrial Hemp to Remediate Heavy-metal-contaminated Soil. Crop, Soil and Environmental Sciences Undergraduate Honors Theses Retrieved from https://scholarworks.uark.edu/csesuht/46