Evaluating the Impact of Tillage on Soil Biological Communities: Fungi, Bacteria and Actinomycetes

Soil microbial communities play a foundational role in maintaining soil fertility, regulating nutrient cycling, enhancing plant productivity, and promoting ecosystem resilience. Among them, fungi, bacteria, and actinomycetes are key biological indicators of soil health, each contributing uniquely to organic matter decomposition, nutrient mobilization, and pathogen suppression. Tillage practices, particularly the intensity and frequency of soil disturbance, have a profound influence on the abundance, diversity, and functionality of these microbial groups. This review synthesizes current findings on how conventional tillage (CT) and conservation tillage (CTi)—including no-tillage (NT) and reduced tillage (RT)—affect soil microbial communities, with an emphasis on fungi, bacteria, and actinomycetes. Evidence from global meta-analyses reveals that conservation tillage significantly enhances microbial biomass, especially in the biologically active topsoil layers (0–20 cm), with fungal and bacterial biomass increasing by 31% and 11%, respectively. NT systems foster fungal dominance, increase the fungal-to-bacterial ratio (F:B), and support the survival of sensitive groups like arbuscular mycorrhizal fungi (AMF), while also promoting copiotrophic bacteria such as Proteobacteria. Actinomycetes, though resilient to moderate disturbance, thrive best under NT and residue-retained conditions. The review also highlights the influence of environmental modulators—such as soil texture, moisture, pH, and organic carbon—on microbial responses to tillage. Despite substantial progress, knowledge gaps remain, particularly regarding actinomycetes’ functional roles under different tillage regimes. Future research should prioritize long-term, multi-location studies and the use of advanced molecular tools to unravel microbial pathways and resilience mechanisms. Conservation tillage emerges as a biologically favorable strategy to support microbial health and soil sustainability.