Correlation Study of Rhizobium Bacteria and Legume Cover Crops (LCC) as Nutrient Providers and Bioremediators on Post-Mining Land at PT. Agincourt Resources

¹ Department of Environmental Engineering, Universitas Sumatera Utara, Medan, Indonesia
² School of Biological Sciences, Universiti Sains Malaysia, Penang, Malaysia
³ PT. Agincourt Resources, Martabe Gold Mine, Jl. Merdeka Aek Pining, Batangtoru, North Sumatera, 22738, Indonesia

^* Corresponding author: yasmineanggiasari@usu.ac.id

Abstract

Gold mining activities have a significant impact on land degradation, particularly in terms of the physical, chemical, and biological aspects of soil. Post-mining land reclamation is an important effort to restore environmental conditions, one of which is through the use of Legume Cover Crops (LCC) that are symbiotic with Rhizobium bacteria. This study aims to analyze the correlation between Rhizobium bacteria and LCC in nutrient supply and their potential as bioremediation agents on post-mining land at PT. Agincourt Resources. The methods used include macroscopic and microscopic observations of root nodules on Vigna unguiculata plants, Desmodium gyrans plants, and Mucuna Bracteata plants grown in the Melisa Dump reclamation area. The results show that Mucuna Bracteata samples had an average of 14 to 28 nodules per plant, while the Desmodium gyrans produced 11 to 23 nodules per sample. Vigna unguiculata had the lowest number of nodules, ranging from 3 to 11 nodules per sample. These findings indicate that the combination of Rhizobium and Mucuna bracteata plants has great potential for improving soil fertility and soil quality in post-mining areas. This study recommends that PT. Agincourt Resources prioritize Mucuna bracteata as a cover crop in their reclamation program.