Soil ciliates' response to glyphosate exposure: A microcosm experiment

Abstract

The widespread use of glyphosate, a broad-spectrum herbicide, in agriculture raises concerns about its impact on non-target organisms and ecosystem functions. Research on glyphosate's effect on soil microorganisms has been inconsistent due to varying methodologies and focuses. To address this, a controlled microcosm study was conducted to investigate glyphosate's impact on soil ciliates, an essential component of soil microbial communities. This study is among the first to examine glyphosate impact on ciliates. The experiment used agricultural soil with glyphosate applied at standard and elevated rates. Ciliate abundance and species richness were monitored in the microcosms at 1-, 7-, and 15-days post-application. Soil ciliates showed remarkable tolerance to glyphosate at standard application rates, with a notable increase in abundance after 15 days, primarily driven by one species' proliferation. This study demonstrates the resilience of ciliate communities to standard glyphosate rates, suggesting their crucial role in maintaining soil functionality in the presence of the herbicide. However, it also highlights potential ecological risks at higher glyphosate concentrations, as evidenced by the loss of ciliate species at the highest rates tested. These findings contribute to our understanding of glyphosate's impact on soil ecosystems and highlights the importance of further research in this area.