Microbial-based biostimulants that increase plant performance and ensure sustainable restoration of degraded soils are of great importance. The aim of the present study was to evaluate the growth promotion ability of indigenous Trichoderma ghanense, T. tomentosum and their complex on early rye seedlings in sustained grassland and arable soil. The impact of soil chemical properties on the ability of selected Trichoderma strains and their complex to promote plant growth was determined by the evaluation of the rye (Secale cereale L.) early seedling growth-measuring the length of shoots and roots as well as their dry weight. Trichoderma species were tested for their ability to produce extracellular degradative enzymes on solid media. Furthermore, the soil properties and CM-cellulase activity of soil were estimated. The indigenous Trichoderma strains possess the capacity to produce enzymes such as peroxidase, laccase, tyrosinase, and endoglucanase. The results indicated a significant (p < 0.05) increase in plant growth and the improvement of some soil chemical properties (total N, mobile humic and fulvic acids, exchangeable K2O, soil CM-cellulase activity) in inoculated soils when compared to the control. The growth of the roots of rye seedlings in sustained grassland was enhanced when T. tomentosum was applied (p = 0.005). There was an increase in total weight and shoot weight of rye seedlings when T. ghanense was used in the arable soil (p = 0.014 and p = 0.024). The expected beneficial effect of Trichoderma spp. complex on rye growth promotion was not observed in any tested soil. The results could find application in the development of new and efficient biostimulants, since not only do physiological characteristics of fungi play an important role but also the quality of the soil has an impact.
Keywords: CM-activity of soil; Trichoderma; growth promotion; physiological characteristics.