Controlling enhanced surface runoff components as a result of a freezing-thawing cycle by inoculating soil bacteria and cyanobacteria

Abstract

Extreme climatic features, such as the freezing-thawing cycles, impact soil erosion processes and make natural-human linked ecosystems more vulnerable to soil erosion and loss. In order to achieve sustainable development, more efficient and comprehensive efforts are necessary. This entails using several techniques to preserve natural resources and ecosystems, resulting in soil and water conservation and economic success. Recent research has focused on natural-based methods, such as developing soil biological crusts by bacteria and cyanobacteria inoculation for soil stability. Modification of soil hydrologic characteristics owing to the inoculation of indigenous microorganisms, on the other hand, has received little attention. The current study assessed the function of inoculation of native bacteria and cyanobacteria in preventing surface runoff during a physical simulation of a freezing-thawing cycle at the laboratory scale. The research soil was obtained mainly from dry terrain in the Badranlou Area of North Khorasan Province and transported to tiny erosion plots (0.5 × 0.5 m) with a constant slope of 20% in the Tarbiat Modares University's Rain and Erosion Simulation Laboratory. The dominant and non-pathogenic bacteria and cyanobacteria found in the study soil's micro-bank were identified, purified, and proliferated. The bacteria and cyanobacteria were inoculated into the study soil before undergoing a six-replication freezing-thawing cycle. The hydrologic outputs of the treated and control plots were compared after a simulated study rain with an intensity of around 70 mm.h-1 continued for 30 min. The surface runoff components improved significantly (p < 0.001) compared to the control and inoculated treatments following individual and combination inoculation of bacteria and cyanobacteria during a freezing and thawing cycle 60 days after inoculation. As a result, bacteria, cyanobacteria, and combined treatments increased the start time by 102%, 228%, and 266%, respectively, and the time to peak by 26%, 49%, and 56%, respectively, while decreasing the runoff peak by 22%, 48%, and 55%, and the runoff volume by 33%, 65%, and 73%. The findings showed that inoculating soil with bacteria and cyanobacteria is a practical, cost-effective, and environmentally friendly way to improve runoff components in locations prone to freezing and thawing.