## 4 Discussion
Using vermicompost or frass can increase the amount of phosphorus available to plants, potentially resulting in better yields and a healthier field. This is an important aspect of sustainable agriculture, allowing for a reduction in the use of mineral fertilizers [52]. To date, limited research has been conducted on the utilization of mealworm frass in plant applications, but some evidence suggests that it promotes plant growth and induces tolerance to abiotic stress [41; 53]. This is important because the agricultural sector is highly sensitive to weather changes. Stress caused by rainfall patterns, drought, or frost affects plants and determines the final yield. In previousstudies, we also confirmed that higher mass rates increased the abundance of plant-available nutrients (N, P, Mg, K, and Na) in peat [27; 49]. Vermicompost (VC) enhances the presence of stable humic and fulvic acids in the compost, which are beneficial for plant growth and soil health [54; 55]. Humic and fulvic acids, as the basic building blocks of humis in the soil, have structure-forming properties. They positively influence water-air relations in the soil solution, increasing its water retention capacity [56]  
Vermicompost significantly affects plant growth by increasing the seed germination rate, seedling index, shoot biomass, root biomass, and total biomass [57]. We also recorded higher abundances of orders Rhizolates (ZM-w) and Burkholderiales (VC and ZM-w), which have well-documented advantageous relationships with plants, showing a positive association between their presence and plant biomass growth [58; 59]. Interestingly, the case of the ZM-w variant showed the greatest potential activity of physiological features, and it was the most distinct from the other variants (Figure 4A). In ZM-w, the Rhizoles order was eudominant, comprising over half of the microbiome (52.2%). Additionally, hormonal compounds, including gibberellins and auxins, were clearly connected in ZM-w (Figure 4B). Several studies have suggested that certain types of _Rhizobium_ function as biocontrol agents by generating siderophores [60]. Our results support this, showing strong relation between Rhizoles and siderophores in PCA (Figure 4B). All these relationships may contribute to better the growth and development of plants using the ZM-w variant. This can help regulate plant metabolism, stimulate root development, improve soil structure, and increase nutrient uptake by plants. Increasing the presence of Proteobacteria, a phylum often associated with enhancing plant growth, reinforces findings regarding the beneficial effects of applied treatments on promoting plant growth and suppressing plant diseases. Insect fras and vermicompost both hold potential as fertilizers and phytortifiers, offering the capacity to enhance plant tolerance to abiotic stresses and bolster resistance against biotic stresses. The locations of TM, VC, ZM-d, and ZM-w in different parts of the biplot, suggesting the unique impact of each type of fertilization on microbiota composition and soil chemistry (Figure 4B). Additionally, recent research has shown that mealworms and superworms can use biodegradable materials (such as polyethylene and polystyrene) as carbon sources in food and degrade them without toxic effects. This can result in a sustainable, waste-free bioremediation cycle [61; 62], and the gut microbiota can also degrade polymer waste [63]. Advantages of using insect fras and vermicompost include improving the soil structure, positively impacting plant health, increasing plant resistance to pathogens, and being safe for the environment as an alternative to chemical solutions. These benefits are attributed to its direct nutrient provision to the soil and plants, along with the presence of valuable biomolecules and beneficial microorganisms, such as plant growth promoters. The comparison of the network analysis results with other results allowed only a partial correlation between the variables and their connections with the treatments used (Figure 5B).