کودهای زیستی در گذار به کشاورزی پایدار: کاوشی جامع در نقش قارچ‌های اندوفیت، تریکودرما، مایکوریزا و باکتری‌های محرک رشد گیاه با تأملی بر پژوهش‌های ایرانی

Background and Objectives: The escalating global demand for food production, driven by a rapidly growing population projected to reach 9.6 to 12.3 billion by 2100, has intensified the pressure on agricultural systems. To meet this demand, traditional agriculture has heavily relied on chemical fertilizers. However, this approach has led to widespread environmental degradation, including soil depletion, groundwater pollution, eutrophication, and a significant reduction in biodiversity. Furthermore, climate change poses a severe threat to global food security, particularly in arid and semi-arid regions like Iran, where abiotic stresses such as drought and salinity are becoming increasingly prevalent. Predictions indicate that climate change could reduce the yields of major staple crops like wheat and rice by over 15% in developing regions by the mid-century. Consequently, there is an urgent need to transition towards sustainable agricultural practices that maintain soil health and crop productivity without the adverse effects of synthetic inputs. Biofertilizers, comprising beneficial microorganisms such as endophytic fungi, Trichoderma spp. arbuscular mycorrhizal fungi (AMF), and plant growth-promoting rhizobacteria (PGPR), emerge as promising eco-friendly solutions. These biological agents employ various mechanisms, including biological nitrogen fixation, phosphate solubilization, siderophore production, and the synthesis of phytohormones, to enhance nutrient use efficiency and plant resilience. Despite the proven efficacy of these microorganisms in controlled environments, their adoption in Iranian agriculture remains limited due to technological, awareness, and commercialization gaps. The primary objectives of this review are to synthesize the current knowledge on the mechanisms and applications of these biofertilizers, evaluate their role in mitigating abiotic stresses with a specific emphasis on findings from Iranian agricultural research, and critically assess the challenges and future prospects for the commercialization of biofertilizers in Iran.




Review Methods: A systematic review was conducted to analyze the landscape of biofertilizer research and application in the context of sustainable agriculture. A comprehensive multi-database search strategy was employed, utilizing international platforms such as Scopus, Web of Science, and ScienceDirect, as well as Iranian national repositories including MagIran, Scientific Information Database (SID), and Civilica. This dual approach ensured the inclusion of both global advancements and localized studies relevant to Iran's specific agro-climatic conditions. The review covered publications spanning from January 2000 to September 2025. Key search terms included "biofertilizers", "sustainable agriculture", "endophytic fungi", "drought resistance", "PGPR", "Trichoderma", "Mycorrhiza", and "Iran". The study critically synthesized data regarding nutrient mobilization mechanisms, physiological responses to stress, and soil health indicators. Furthermore, the review analyzed the current status of biofertilizer registration and standardization in Iran, referencing national standards (ISIRI) to evaluate the gap between research output and market availability.
Results: The synthesized literature reveals that biofertilizers significantly enhance agricultural sustainability through a complex network of direct and indirect mechanisms. Regarding nutrient mobilization, Arbuscular Mycorrhizal Fungi (AMF) play a pivotal role by extending hyphal networks into the soil matrix, thereby increasing the absorptive surface area of roots. This mechanism significantly enhances the uptake of immobile nutrients, particularly Phosphorus (P) and Zinc (Zn), and can reduce the necessity for chemical phosphorus fertilizers by approximately 20-40%. Concurrently, Plant Growth-Promoting Rhizobacteria (PGPR) such as Azotobacter, Azospirillum, and Rhizobium facilitate biological nitrogen fixation, capable of contributing up to 300 kg of nitrogen per hectare annually, while also solubilizing insoluble phosphates through the secretion of organic acids. In the context of stress mitigation, the review highlights that biofertilizers induce systemic tolerance to abiotic stresses, which is crucial for farming in Iran's dry climate. Beneficial microbes upregulate the expression of stress-responsive genes, enhance the activity of antioxidant enzymes like Superoxide Dismutase (SOD) and Catalase (CAT) to scavenge Reactive Oxygen Species (ROS), and promote the accumulation of osmolytes such as proline. Specifically, Trichoderma species have been shown to alleviate salinity stress in crops like pistachio and tomato by regulating the Na+/K+ ratio and enhancing root architecture. Endophytic fungi contribute by synthesizing phytohormones (IAA, GA) that boost root biomass and maintain chlorophyll content under water-deficit conditions. Analysis of Iranian research indicates significant positive outcomes in field trials. Application of combined biofertilizers has demonstrated yield increases ranging from 10% to 67% in strategic and medicinal crops such as saffron, quinoa, canola, and medicinal herbs, alongside improvements in quality parameters like protein and oil content. However, despite the existence of over 900 research articles and the establishment of national standards (ISIRI 22300-22306), the commercialization landscape presents a paradox. While the scientific infrastructure exists, Iran’s market share of biofertilizers remains below 5%. The review identifies key barriers, including the instability of microbial formulations under harsh field conditions, lack of farmer awareness, and insufficient policy incentives compared to subsidized chemical fertilizers.
 




Conclusion: This comprehensive review confirms that biofertilizers harnessing endophytic fungi, Trichoderma, mycorrhizae, and PGPR offer a robust and viable framework for transitioning to sustainable agriculture. These biological inputs address critical nutrient inefficiencies and environmental stresses while allowing for a significant reduction in chemical input dependency. The evidence confirms their efficacy in enhancing crop yields (10-40%) and improving stress tolerance, which is vital for food security in changing climates. However, bridging the significant gap between research findings and practical application in Iran requires a multi-faceted approach. Future development priorities must shift from simple single-strain inoculants to the development of stable, multi-strain consortia adapted to local abiotic stresses (salinity and heat). Furthermore, the establishment of strict quality control protocols based on national standards and the implementation of supportive policy incentives are essential to build farmer confidence. By integrating these biotechnological tools with modern agronomic practices, it is possible to foster resilient agroecosystems that ensure both economic viability and environmental harmony.