Mineral solubilizing microorganisms and their combination with plants enhance slope stability by regulating soil aggregate structure

Lingjian Wang; Xinggang Tang; Xin Liu; Rengui Xue; Jinchi Zhang

doi:10.3389/fpls.2023.1303102

Mineral solubilizing microorganisms and their combination with plants enhance slope stability by regulating soil aggregate structure

Front Plant Sci. 2023 Dec 28:14:1303102. doi: 10.3389/fpls.2023.1303102. eCollection 2023.

Authors

Lingjian Wang¹, Xinggang Tang^{2

3}, Xin Liu¹, Rengui Xue¹, Jinchi Zhang¹

Affiliations

¹ Jiangsu Province Key Laboratory of Soil and Water Conservation and Ecological Restoration, Nanjing Forestry University, Nanjing, Jiangsu, China.
² Jiangxi Institute of Land Space Survey and Planning, Nanchang, Jiangxi, China.
³ Technology Innovation Center for Land Spatial Eco-protection and Restoration in Great Lakes Basin, Ministry of Natural Resources (MNR), Nanchang, Jiangxi, China.

Abstract

Introduction: The stability of exposed slopes is prone to natural disasters, seriously threatening socio-economic and human security. Through years of exploration and research, we proposed an active permanent greening (APG) method based on patented mineral solubilizing microorganisms (MSMs) as an improvement over the traditional greening method.

Methods: In this study, we selected two MSMs (Bacillus thuringiensis and Gongronella butleri) and a plant species (Lolium perenne L.) set up six treatments (T1, T2, T3, T4, T5, and T6) to investigate the effectiveness of the MSMs and their combinations with the plant species on the soil stability using APG method.

Results: We noted that both MSMs and the plant species significantly improved soil aggregate stability and organic matter content. Of all the treatments, the T1 treatment exhibited better results, with soil aggregate stability and organic matter content increased to 45.63% and 137.57%, respectively, compared to the control. Soil stability was significant positively correlated with macroaggregate content and negatively with microaggregates. Using structural equation modeling analysis, we further evaluated the mechanism underpinning the influence of organic matter content and fractions on the content of each graded agglomerates. The analysis showed that the macroaggregate content was influenced by the presence of the plant species, primarily realized by altering the content of organic matter and aromatic and amide compounds in the agglomerates, whereas the microaggregate content was influenced by the addition of MSMs, primarily realized by the content of organic matter and polysaccharide compounds. Overall, we observed that the effect of the co-action of MSMs and the plant species was significantly better than that of using MSMs or the plant species alone.

Discussion: The findings of this study provide reliable data and theoretical support for the development and practical application of the APG method to gradually develop and improve the new greening approach.

Keywords: infrared spectral analysis; organic matter characteristics; slope stability; soil aggregates; structural equation modeling.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. Postgraduate Research & Practice Innovation Program of Jiangsu Province [KYLX16_0864]; Innovation and Promotion of Forestry Science and Technology Program of Jiangsu Province [LYKJ (2021) 30]; Scientific Research Project of Baishanzu National Park [2021ZDLY01]; Priority Academic Program Development of Jiangsu Higher Education Institutions [PAPD]. Jiangsu Science and Technology Plan Project [BE2022420].