Microbial and Non‐Microbial Biostimulants for Soil Health in Managed Agricultural Systems: A Scientometric Analysis of Bioinputs From 2021 to 2025

ABSTRACT Background Biostimulants and related bioinputs encompass microbial and non‐microbial strategies used to improve plant performance, nutrient‐use efficiency, stress resilience, and soil functioning. Aim For this study, plant biostimulants were operationally defined as substances or microorganisms applied to enhance nutrient‐use efficiency, tolerance to abiotic stress, and/or crop quality independently of their direct nutrient content. Methods We mapped global scientific output on these technologies in sustainable agriculture from 2021 to 2025 using the Web of Science Core Collection and a broad topic‐based search, resulting in a final corpus of 1400 documents. Analyses were conducted using Bibliometrix/Biblioshiny and VOSviewer. Results Growth‐related themes remained quantitatively dominant (“growth,” 258 occurrences; “plant‐growth,” 229; “yield,” 210), whereas more recent but lower frequency topics such as “quality,” biochar, and the rhizosphere microbiome indicated thematic diversification rather than displacement of productivity‐oriented research. Microbial inoculants, including PGPR/PGPM, represented a prominent component, while humic substances, seaweed‐derived inputs, and mixed formulations broadened the biostimulant landscape. Biochar and organic residues were interpreted as related soil amendments or formulation carriers when they co‐occurred with biostimulant strategies, rather than being automatically classified as biostimulants. Conclusion Overall, current research increasingly integrates nutrient‐use efficiency, soil health, microbiome management, and crop‐specific combinations of microbial and non‐microbial technologies.