Evaluation of Granule-Based Biopreparations for Enhancing Germination: A Comparative Study
The decline in soil fertility and the overuse of chemical fertilizers pose significant challenges in modern agriculture. This research investigated the potential of biopreparation in form of granules created from five selected microbial strains - Bacillus subtilis, Prestia megaterium, Bacillus velezensis, Bacillus licheniformis, and Paenibacillus amylolyticus to enhance corn and rye germination. Metagenomic studies were performed to demonstrate whether significant changes occur in the structure of the soil microbiota. Moreover, it evaluated the survival of vegetative forms and spores over six months and the time of release of microorganisms in different granule formulations. Survivability of bacteria in granules was high and dependent on form - post-cultivation liquid or spray-dried bacteria powder. On the other hand, physical properties of granules were more dependent on the carrier type - chalk or bentonite and binder agent - water or 50% molasses. Two granulates were chosen for the evaluation of impact on germination and soil microbiota based on physical properties and survivability. Research was conducted in grow-box set (RoyalRoom Classic C80S), with 12 hours of lighting (250W CFL Phytolite DUAL) with stable humidity of 60 +/- 2% (INKBIRD Humidity Controller) for 10 days. On the 5th and 10th day above-ground parts of the plants were measured. After the cultivation the length of the roots, as well as the dry matter of the above-ground parts and the whole plants were measured. The chlorophyll content was assessed by extraction in ethanol and spectrophotometric measurement at wavelengths of 645 nm, 649 nm, 654 nm and 665 nm (Multiskan GO Microplate Spectrophotometer). Soil samples were used to assess pH, total bacteria count and DNA isolation. DNA from the soil was isolated using the GeneMATRIX Soil DNA Purification Kit. Sequencing of the 16S rDNA region was performed. Effect of granules was compared to untreated control and two commercially available fertilizers - multicomponent fertilizer and nitrogen fertilizer.