The role of fungi in enhancing plant productivity in grey-brown soils

Abstract

The Republic of Azerbaijan is experiencing issues such as soil salinisation, pollution and declining productivity, which are particularly evident on the Absheron Peninsula. This peninsula is considered one of the driest regions in the Caucasus. It contains a significant amount of depleted soil. This highlights the importance of taking a more careful and sustainable approach to land use in the region, as well as increasing the productivity of crops grown on these soils. Soil samples were collected using standard methods from various types of soil (relatively clean, polluted, irrigated, etc.) across the Absheron Peninsula. The study isolated 79 fungal species from the soils of the Absheron Peninsula in the Republic of Azerbaijan, 28 of which were involved in forming epiphytic mycobiota. Evaluating these species' interactions with phytopathogenic fungi revealed that only those belonging to the Trichoderma genus demonstrated high antagonistic potential. Notably, strains T. citrinoviride AEF-2024 and T. harzianum AEF-2024 exhibited the greatest activity. An assessment of the effect of CF obtained from these two strains on plant growth and productivity revealed that seed germination in tomato, cucumber, wheat and pea increased by 4.7–6.7%. The most favourable results were achieved with a 50-fold dilution of CF under optimal conditions. In this case, seed germination increased by 1.4–1.5 times for T. citrinoviride and by 1.3–1.8 times for T. harzianum, compared with the untreated control. Furthermore, pre-sowing treatment of tomato seeds with CF improved plant morphometric characteristics and increased yield per plant. Specifically, CF from T. citrinoviride AEF-2024 increased yield per plant by 1.25 times compared to the control, while CF from T. harzianum AEF-2024 increased yield per plant by 1.20 times. The research clearly demonstrates that using fungi isolated from stressed agroecosystems is an effective way to increase crop productivity in such conditions.