2025, Vol. 5, Issue 2, Part B

Potato cultivation in intensive production systems relies heavily on mineral fertilizers, which can degrade soil health and suppress beneficial rhizosphere microorganisms over time. Integrated fertilization, combining mineral fertilizers with organic amendments and microbial inoculants, offers a potential pathway to sustain productivity while improving soil biological functioning. This field study evaluated the influence of conventional mineral fertilization (CF), sole organic fertilization (OF) and integrated fertilization (IF) on soil fertility, beneficial rhizosphere microbial populations, microbial diversity and tuber yield and quality in a processing potato cultivar grown under subtropical conditions. The experiment was conducted for two seasons in a randomized complete block design with four replications. Soil properties, functional microbial groups (free-living nitrogen-fixing bacteria, phosphate-solubilizing bacteria, plant growth-promoting rhizobacteria and arbuscular mycorrhizal fungi), bacterial diversity (16S rRNA amplicon sequencing) and yield and quality components were measured at key crop stages. IF increased soil organic carbon and maintained higher available nitrogen and phosphorus compared with CF, while OF mainly improved carbon status. All beneficial microbial groups were significantly more abundant under IF and OF than under CF, with IF recording the highest populations and mycorrhizal colonization. Bacterial diversity and richness were greatest under IF, and principal component analysis showed clear separation of treatments, with IF associated with enhanced soil fertility, microbial indicators and yield. IF increased total and marketable tuber yields by approximately 9-10% and 15-18%, respectively, over CF and OF, and modestly improved dry matter and processing quality. Strong positive correlations were observed between functional microbial populations, bacterial diversity and yield components. The results indicate that integrated fertilization can reduce reliance on sole mineral fertilization, foster functionally enriched rhizosphere microbial communities and enhance both productivity and quality in potato, providing a robust foundation for microbiome-informed integrated nutrient management strategies.