Work

Potato straw incorporation improves soybean agronomic traits and yield components and is associated with shifts in rhizosphere soil properties microbial communities and metabolites

Year: 2026

Type: article

Abstract: Background The soil-improving effects of cereal straw incorporation have been well documented; however, potato straw differs markedly from cereal straw in composition and degradation characteristics, and whether straw return is associated with the soil microbial ecosystem and with gains in yield components through pathways similar to those of cereal straw remains unclear. Methods In this study, a field-embedded pot experiment was conducted to characterize the interaction network among soil physicochemical properties, microbial communities, and metabolites under potato straw incorporation, and to elucidate its regulatory effects on soybean growth and yield components. Results Compared with no incorporation, straw incorporation significantly increased soil organic matter (by 21.60%), available potassium (35.39%), alkali-hydrolyzable nitrogen (16.94%), and available phosphorus (15.42%), and significantly enhanced the activities of acid phosphatase (28.63%) and polyphenol oxidase (16.04%). Amplicon sequencing identified treatment-associated enrichment of bacterial and fungal taxa previously linked to residue decomposition, nutrient cycling (e.g., Paenibacillus and Nitrosomonadaceae ), or plant-beneficial interactions(e.g., arbuscular mycorrhizal fungi [Glomeromycota] and Bionectria ). Correlation analysis between the soil metabolome and the microbial community showed that both bacterial and fungal communities exhibited a dichotomous pattern of contrasting metabolite preferences: among bacteria, Proteobacteria-dominated taxa were positively correlated with organic acid metabolites, whereas taxa dominated by Gemmatimonadota, Firmicutes, and Actinobacteria were positively correlated with aromatic amino acids and nitrogen-containing heterocyclic compounds, each group being negatively correlated with the metabolites preferred by the other; among fungi, root-symbiotic taxa were positively correlated with secondary metabolites such as flavonoids, whereas saprotrophic fungi were positively correlated with plant-residue decomposition markers such as 2-furoic acid and geranylgeraniol. Three relatively independent organic nitrogen transformation pathways—arginine metabolism, histidine degradation, and purine nucleoside catabolism–were also detected, and pH, organic matter, urease (S-UE), and soybean isoflavone metabolites (daidzein and genistin) showed strong co-occurrence patterns with other network members. Conclusion Soybean plant height, stem diameter, pods per plant, and 100-seed weight significantly increased by 14.93%, 17.77%, 19.10%, and 11.40%, respectively. In summary, potato straw incorporation broadened the soil organic nitrogen substrate spectrum by reshaping the soil physicochemical property–microbe–metabolite interaction network, thereby promoting soybean growth and yield components formation through multi-pathway synergy. These findings provide a theoretical basis for the resource utilization of potato straw.

Source: Frontiers in Microbiology

DOI: 10.3389/fmicb.2026.1990822