Interactive effects of bacterial biofertilizers and soil properties on yield and quality of saffron (Crocus sativus L.): A Meta‑Analysis

Khezri, Ghaffar; Moradi, Rooholla; Hossein Jafari, Samira; Yousefi Javan, Iman

doi:10.22034/jmpb.2027.372232.2146

Interactive effects of bacterial biofertilizers and soil properties on yield and quality of saffron (Crocus sativus L.): A Meta‑Analysis

Articles in Press

Document Type : Research Article

Authors

¹ Department of Plant Production, Faculty of Agriculture, University of Torbat Heydarieh

² Department of Nature Engineering and Medicinal Plants, Faculty of Agriculture, University of Torbat Heydarieh, Torbat Heydarieh, Iran

10.22034/jmpb.2027.372232.2146

Abstract

This meta‑analysis systematically reviewed the effects of bacterial biofertilizers on quantitative and qualitative traits of saffron (Crocus sativus L.) using data from 32 articles retrieved from Web of Science (50%), Scopus (53%), ScienceDirect (16%), and Magiran (47%). Statistical analyses included multivariate regression, correlation matrix analysis, and principal component analysis (PCA). These methods identified relationships between soil properties, management practices, and saffron yield and quality. Bacterial species richness and soil organic matter percentage were the strongest positive predictors of saffron traits, together explaining 59–81% of the variation in yield and secondary metabolite content. Fresh flower yield increased by 43% per additional bacterial species and by 51% per 1% increase in organic matter. Dry stigma yield increased by 27% per additional bacterial species and by 163% per 1% increase in organic matter. Conversely, each unit increase in EC and chemical fertilizer reduced fresh flower yield by 2.4% and 0.4%, and dry stigma yield by 18.2% and 0.3%, respectively. PCA revealed that biological soil fertility parameters (organic matter, biofertilizer complexity, and treatment duration) clustered separately from chemical inputs, indicating that saffron yield and quality are driven primarily by biological rather than chemical nutrient intensity. Soil texture analysis showed that loam‑clay‑sandy soils maximized fresh flower yield (124% increase), whereas clay loam soils optimized crocin and picrocrocin production (18–38% increases). These findings demonstrate that sustainable saffron production requires integrated bio‑organic management strategies prioritizing bacterial richness , organic matter enrichment, and soil pH optimization over synthetic chemical fertilizers.

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