Glasnik Zaštite Bilja, Vol. 49. No. 4., 2026.
Professional paper
Application of microbiological preparations and increasing phosphorus availability in soil in organic agricultural production
David Gluhić
; Agro Expert d.o.o., Funtana, Hrvatska
*
Goran Fruk
; Sveučilište u Zagrebu Agronomski fakultet, Zagreb, Hrvatska
Damir Lučić
; Inventivna rješenja d.o.o., Velika Gorica, Hrvatska
* Corresponding author.
Abstract
Phosphorus (P) availability is a major limiting factor in organic agriculture, as most soil P rapidly becomes fixed into insoluble forms with aluminium, iron, or calcium and is therefore inaccessible to plants. Phosphorussolubilizing microorganisms (PSM)—particularly Pseudomonas, Bacillus, Rhizobium species and arbuscular mycorrhizal fungi (AMF)—play a central role in converting these forms into plantavailable orthophosphates. Their activity relies on the secretion of organic acids, metal chelation, rhizosphere acidification, and enzymatic mineralization of organic P through phosphatases and phytases. The synergy between phosphatesolubilizing bacteria (PSB) and AMF is especially important: bacteria dissolve mineral P, while AMF hyphae capture the released phosphate and transport it directly to the root, preventing refixation. This interaction enhances root development, hormonal balance, and plant tolerance to abiotic stresses such as drought. In perennial crops like vineyards and orchards, microbial inoculation increases biomass, improves nutrient uptake, and enhances fruit quality through higher levels of phenolics, flavonoids, and sugars. Metaanalyses confirm that PSM increase P availability, improve soil microbial diversity, and allow reductions in mineral fertilizers without yield loss. Key challenges include selecting effective strains, ensuring inoculum stability under field conditions, and developing advanced formulations. Integrating PSM and AMF represents a core strategy for sustainable agriculture, improved soil fertility, and climatechange resilience.
Keywords
phosphorus; phosphorus solubilization; rhizosphere; phosphorusmobilizing microorganisms; organic agriculture
Hrčak ID:
350034
URI
Publication date:
15.7.2026.
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