Influence of microorganisms on thermal conductivity of soils and its potential impact on soil aggregation

Abstract

The significance of soil thermal conductivity in designing energy geo structures lies in its role in determining the heat transfer rate through materials. This study delves into the impact of bacterial presence on soil thermal conductivity, utilizing soil samples from six distinct regions in Gujarat—Surat, Madhavpur, Bhadbhut, Navsari, Dholera, and Bhuj. Employing a laboratory-scale experimental setup based on guarded hot plate method, thermal conductivity of soil samples was measured. Microorganisms were isolated from the soil samples using serial dilution and spread plate method, with two types of microorganisms selected from each soil sample. Measurements were conducted at curing periods of 7, 14, and 28 days, and comparative analysis of thermal conductivity values before and after treatment were performed. The findings revealed that E. coli led to reduction in thermal conductivity values in sandy soil, while S. aureus exhibited favorable outcomes in sandy soil compared to clayey soil. The study reveals significance of natural microbes present in raw soil and its potential use to enhance thermal conductivity of soils. © The Author(s) under exclusive licence to Society for Plant Research 2024.