Effect of Symbiotic Microorganisms on Turfgrass under Two Irrigation Regimes

Aim: Efficient use of irrigation water is one of the main goal for turfgrass keepers. In this study, the ability of selected symbiotic microorganisms to improve turfgrass visual quality and growth under two different irrigation regimes was investigated.

Study Design: Three soil inoculants, Bacillus amyloliquefaciens FZB42 (B), Glomus intraradices (G) and Trichoderma harzianum (strain T-22) (T) were applied to a loamy sand soil in order to colonize Festuca arundinacea, ‘Grande II’. Regarding irrigation differentiation, a stress cycle, during which soil moisture was kept at the level of 50% of available soil water, was applied.

Place and Duration of Study: The experiment was conducted under open field conditions in North West Greece during the summer of 2014.

Methodology: Twenty four rectangular compartments of 1x2m each hosted the plots. The experimental design was multi-factorial, involving two factors (the three above mentioned root symbiotic microorganisms and two soil moisture level (100% and 50% of available soil water) treatments) and completely randomized regarding the microorganisms, with 3 replications per treatment. A number of parameters like climatic conditions, soil moisture, colonization, dry weight of clippings and canopy spectral reflectance were measured.

Results: The results showed that T. harzianum T-22 and B. amyloliquefaciens FZB42 promoted the aerial plant growth (total dry weight of clippings) of F. arundinacea under water stress conditions while G. intraradices had no effect on the growth. In qualitative terms, no statistically significant differences were found among treatments.

Conclusion: The results of this open field study provide promising evidence regarding the potential for agronomic application of the soil inoculants that were evaluated.