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ORIGINAL RESEARCH article

Front. Earth Sci.
Sec. Geoscience and Society
Volume 12 - 2024 | doi: 10.3389/feart.2024.1414437
This article is part of the Research Topic Constraining the Potential of Land-Based Negative Emissions Technologies (NETs) From a Data-Driven Perspective View all articles

Mine waste rock as a soil amendment for enhanced weathering, ecosystem services, and bioenergy production

Provisionally accepted
Mackenzie D. Russell Mackenzie D. Russell 1Katherine Heckman Katherine Heckman 2*Lei Pan Lei Pan 1Xinyu Ye Xinyu Ye 1Ronald S. Zalesny Ronald S. Zalesny 3Evan S. Kane Evan S. Kane 1,2
  • 1 Michigan Technological University, Houghton, Michigan, United States
  • 2 Northern Research Station, Forest Service (USDA), Houghton, MI, United States
  • 3 Northern Research Station, Forest Service (USDA), Madison, United States

The final, formatted version of the article will be published soon.

    Enhanced weathering of terrestrial rock material is a promising method for the removal of anthropogenic CO2 emissions from the atmosphere. Herein, we demonstrate that an ameliorated mining waste product can be effectively weathered in the soil environment when used as a soil amendment in conjunction with the cultivation of fast-growing willows (Salix matsudana Koidz. ⨯ S. alba L. 'Austree') in a pot study environment. Utilizing this locally sourced amendment minimizes emissions associated with grinding and transportation of enhanced weathering materials. Results showed that the willows were able to tolerate the relatively high metal concentrations of this amendment and sequester inorganic carbon (C) through the production of bicarbonate in soil solution. During the period of peak plant growth (10 weeks after planting), alkalinity measurements of soil solution from pots with willows and the addition of 25% by mass mine waste product indicated an additional 10 mg of inorganic C sequestration per liter of leached soil solution compared to unamended soils with willows. This represents 4.5 times the inorganic C sequestration rate of unamended soils. The addition of ameliorated mining waste also increased the pH of the soil solution by up to two units (pH of 6 in control vs. pH of 8 with the addition of 25% by mass mineral amendment). In addition to inorganic C sequestration, weathering of the ameliorated mining waste product may also provide base cations (such as calcium and magnesium) which could improve soil fertility. These results are encouraging for future investigation of ameliorated mine waste rock to sequester carbon and enhance the production of willows grown for ecosystem services and phytotechnologies.

    Keywords: Phytotechnologies1, Enhanced weathering2, carbon sequestration3, bioenergy production4, soil organic matter5

    Received: 08 Apr 2024; Accepted: 26 Jul 2024.

    Copyright: © 2024 Russell, Heckman, Pan, Ye, Zalesny and Kane. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Katherine Heckman, Northern Research Station, Forest Service (USDA), Houghton, MI, United States

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.