Shear Strength Improvement of Silty Soil Via Microbial-Induced Calcite Precipitation for Wind Erosion Mitigation

The low shear strength of silty soils in arid and semi-arid regions contributes significantly to their vulnerability to wind erosion. This study evaluates the effect of Microbial-Induced Calcite Precipitation (MICP) using Bacillus thuringiensis on the shear strength parameters of silty soils from Northwestern Nigeria. Laboratory tests, including direct shear testing, were conducted on untreated and MICP-treated soil samples to assess changes in cohesion and internal friction angle. Results show that bio-treatment significantly alters the shear strength behavior of silty sand. Cohesion decreased from 38.21 kN/m² (control) to a minimum of 25.11 kN/m², indicating a transition from clay-like behavior to a more stable granular structure. Conversely, the angle of internal friction increased from 28.2° to a peak of 42.0°, while shear strength improved markedly from 26.3 kN/m² to 82.39 kN/m² at the optimum treatment condition of 1.8 × 10⁹ cells/ml and 0.75 M. The improvements are attributed to calcium carbonate precipitation via microbial-induced calcite precipitation (MICP), which enhances interparticle bonding, increases surface roughness, and reduces pore spaces. Statistical analysis using two-way ANOVA confirmed that both bacterial density and reagent concentration have significant effects (p < 0.05) on all measured parameters.
Microstructural analysis (SEM) revealed a transition from a loose, porous structure to a dense, cemented matrix, while XRD analysis confirmed the presence of calcite as the dominant cementing agent. The findings demonstrate the potential of Bt-based MICP as an effective and sustainable technique for improving the mechanical properties and erosion resistance of silty sand.

Silty sand, Bacillus Thuringiensis, Soil crust, Microbial-induced calcite precipitate

1. Abubakar, M. (2023). Evaluation of bio-cementation of lateritic soil with brevibacillus brevis using different modes of application for road construction. A Thesis Submitted to the Postgraduate School, Ahmadu Bello University, Zaria. [Google Scholar] [Crossref]

2. Ali N, Karkush M. (2021). “Improvement of Unconfined Compressive Strength of Soft Clay using Microbial Calcite Precipitates.” Journal Engineering; 27(3):67–75. [Google Scholar] [Crossref]

3. Ankur N., Noosrat R., Ashikuzzaman M., Syed A. M. (2019). “Department Comparative Study of Consistency Behavior and Shear Strength of Clayey Soils of Rajshahi District, Bangladesh.” Journal of Civil, Construction and Environmental Engineering; 4(1): 28-34 doi: 10.11648/j.jccee.20190401.13 [Google Scholar] [Crossref]

4. Bassey, A. B. (2021). “Microbial-Induced Calcite Precipitate Improvement Potential of Black Cotton Soil with Bacillus Coagulans.” A dissertation submitted to the Postgraduate School, Ahmadu Bello University, Zaria. [Google Scholar] [Crossref]

5. BS 1377 (1990). Method of Testing Soils for Civil Engineering Purposes. British Standard Institute, BSI, London. [Google Scholar] [Crossref]

6. BS 1924 (1990). Method of Test for Stabilized Soils. British Standard Institute BSI London [Google Scholar] [Crossref]

7. DeJong, J. T., Mortensen B. M., Martinez B. C., and Nelson D. C. (2010). "Bio-mediated soil improvement." Ecological Engineering, 36(2):197 - 210. [Google Scholar] [Crossref]

8. Devrani, R., A. A. Dubey, K. Ravi, and Sahoo, L. (2021). “Applications of bio-cementation and bio-polymerization for aeolian erosion control.” J. Arid. Environ. 187 (Aug): 104433. [Google Scholar] [Crossref]

9. https://doi.org/10.1016/j.jaridenv .2020.104433. [Google Scholar] [Crossref]

10. Duniway, M. C., Pfennigwerth, A. A., Fick, S. E., Nauman, T. W., Belnap, J., & Barger, N. N. (2019). Wind erosion and dust from US drylands: a review of causes, consequences, and solutions in a changing world. Ecosphere, 10(3), e02650. https:// doi.org/10.1002/ecs2.2650. [Google Scholar] [Crossref]

11. Fick, S.E., Barger, N., Tatarko, J., Duniway, M.C. (2020). Induced biological soil crust controls on wind erodibility and dust (PM10) emissions. Earth Surf. Process. Landforms 45 (1), 224–236. https://doi.org/10.1002/esp.4731. [Google Scholar] [Crossref]

12. Gang, Li, Jia, L., Jinli, Z. and Shufeng, C. (2023). “Shear Strength Behaviors of Aeolian Sand Solidified by Microbially Induced Calcite Precipitation and Basalt Fiber Reinforcement.” Materials; 16(17): 5857. doi: 10.3390/ma16175857 [Google Scholar] [Crossref]

13. Garba A. M. (2025). Evaluation of bacillus brevis - induced calcite precipitate for mitigation of aeolian soil erosion. . A Thesis Submitted to the Postgraduate School, Ahmadu Bello University, Zaria [Google Scholar] [Crossref]

14. Gowthaman, S., Nakashima, K., Kawasaki, S. (2020). “Freeze-thaw durability and shear responses of cemented slope soil treated by microbial induced carbonate precipitation, Soils Found.” 60 (2020) 840–855, https://doi.org/10.1016/j.sandf. 2020.05.012 [Google Scholar] [Crossref]

15. Gil-Loaiza, J., Field, J.P., White, S.A., Csavina, J., Felix, O., Betterton, E.A., S´aez, A.E., Maier, R. M. (2018). Phytoremediation reduces dust emissions from metal (loid)- contaminated mine tailings. Environ. Sci. Technol. 52 (10), 5851–5858. [Google Scholar] [Crossref]

16. Harkes, M. P., Van Paassen, L. A., Booster, J. L., Whiffin, V. S., and Van Loosdrecht, M. C. M. (2010). “Fixation and distribution of bacterial activity in sand to induce carbonate precipitation for ground reinforcement.” Ecological Engineering, 36(2) :112-117. [Google Scholar] [Crossref]

17. Jia, L., Gang, L., and Xi’an, L. (2022). “Geotechnical Engineering Properties of Soils Solidified by Microbially Induced CaCO3 Precipitation (MICP).” Hindawi Advances in Civil Engineering;12:1, Article ID 6683930https://doi.org/10.1155/2021/6683930 [Google Scholar] [Crossref]

18. Liang, S., Xiao, X., Fang, C., Feng, D., Wang, Y. (2022). “Experimental Study on the Mechanical Properties and Disintegration Resistance of Microbially Solidified Granite Residual Soil.” Crystals 2022, 12:132. https://doi.org/10.3390/cryst12020132 [Google Scholar] [Crossref]

19. Microbiology Procedures/Guidelines (2010). "College of Physicians and Surgeons of Saskatchewan.” Laboratory Quality Assurance Program. [Google Scholar] [Crossref]

20. Ng, W., Lee, M. and Hii, S. (2012). “An Overview of the Factors Affecting Microbial-Induced Calcite Precipitation and its Potential Application in Soil Improvement.” World Academy of Science, Engineering and Technology International Journal of Civil and Environmental Engineering (6)2:188-193. [Google Scholar] [Crossref]

21. Nikseresht, F., Landi, A., Sayyad, G., Ghezelbash, G., Schulin, R. (2020). Sugarecane molasse and vinasse added as microbial growth substrates increase calcium carbonate content, surface stability and resistance against wind erosion of desert soils. J. Environ. Manag. 268, 110639. O’Brien, P., Neuman, C.M., 2012. A wind tunnel [Google Scholar] [Crossref]

22. Osinubi, K. J., Sani, J. E., Eberemu, A. O., Ijimdiya, T. S. and Yakubu, S. E.(2019d). ‘Unconfined compressive strength of Bacillus pumilus treated lateritic soil.’ Proceedings of the 8th International Congress on Environmental Geotechnics (ICEG 2018), “Towards a Sustainable Geoenvironment” Edited by Liangtong Zhan, Yunmin Chen and Abdelmalek Bouazza, 28th October – 1’st November, Hangzhou, China,c Springer Nature Singapore Pte Ltd., 3 : 410–418, Online: [Google Scholar] [Crossref]

23. https://doi.org/10.1007/978-981-13- 2227-3_51 [Google Scholar] [Crossref]

24. Oyelakin, A. M. (2025). “Mitigation of wind erosion of semi-arid zone soil using bacillus megaterium in microbial - induced calcite precipitation.” A Thesis Submitted to the Postgraduate School, Ahmadu Bello University, Zaria. [Google Scholar] [Crossref]

25. Sani, J. E. and Bala, K. B. (2021). "Microbial Induced Modification of Silty Soil Using Bacillus Coagulans for Building Foundation.” journal of science technology and education 9(3), [Google Scholar] [Crossref]

26. september, 2021. ISSN: 2277-0011; 1(1) 12 – 24 [Google Scholar] [Crossref]

27. Zamani, A., and Montoya, B. M. (2015). “Undrained Behavior of Silty Soil Improved with Microbial Induced Cementation.” 6th International Conference on Earthquake Geotechnical Engineering 1-4 November 2015, Christchurch, New Zealand [Google Scholar] [Crossref]

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