## 4 Discussion  
Pearson correlation shows that sites with more soil exchangeable K also tend to have lower exchangeable Ca, nitrogen in leaves, corncob weight, corncob length, cob weight, cob length, plant fresh weight, and plant diameter. This could be because of a nutrient imbalance where one nutrient was more present in the organic amendments, for example, potassium in vermicompost leachate. Principal component analysis indicated that vermicompost leachate (T1) was closely associated with higher levels of potassium and a notable presence of _Pseudomonas_ spp., communicating that it may have promoted specific beneficial microbial groups and contributed to soil nutrient enrichment, even if that did not translate into the highest yield. Biochar (T2) stood out for improving soil physical and chemical characteristics, enhancing microbial community diversity, and supporting greater plant biomass, suggesting a more balanced and sustained impact on soil-plant interactions. The combined treatment (T3) showed intermediate performance, implying that the interaction between the two amendments might not have been fully synergistic. This pattern highlights that biochar alone may offer more consistent and broad-spectrum benefits, while vermicompost leachate may require careful management to optimize its effectiveness. The dosage of biochar and leachate was selected according to the recommendations of the \"Agricultural Research and Technology Transfer Unit in Organic Solid Waste Management\". In the case of biochar, we also followed the guidelines of the International Biochar Initiative and the European Biochar Certificate guideline. Relative to these documents, the biochar was under the maximum permissible limit for organic and conventional agriculture. However, the EC was 11.22 dS m\({}^{-1}\), so this could affect the performance of maize popcorn, and we did not observe notable differences in comparison with the Control. Previous studies have shown that the foliar application of vermicompost leachate can enhance growth and physiological responses in crops under saline conditions. For instance, it promoted the development of pomegranate seedlings by improving tolerance to salinity stress [33]. Similarly, other research demonstrated that a low dose of solid vermicompost applied before planting improved strawberry yield in the first year; however, in the absence of further fertilization, yields declined to control levels in subsequent years. Although vermicompost leachate did not improve yield, it was associated with better fruit quality [34]. In our study, a slight reduction in electrical conductivity (EC) was observed in the leachate treatments, although this difference was not statistically significant, suggesting limited efficacy under the experimental conditions. The chemical characterization of the leachate has an approximate organic matter content of 60%, with total humic substances representing 80% of the organic matter, total nitrogen at 2%, and total organic nitrogen at 1.5%. Also, the leachate has an interesting microbial community, including amylolytic, cellulolytic, nitrosant, nitricant, sulfate reducers, sulfur oxidants, aerobic nitrogen-fixing, anaerobic nitrogen-fixing, denittifying, ammonifying, actinomycetes, aerobic, and anaerobic bacteria [35]. Additionally, a pH of 8.40 and EC of 3.34 dS m\({}^{-1}\) enabled microbial growth, particularly of bacteria, for example, _Pseudomonas_ spp., as could be seen in the PCA for T1. Some authors mentioned that the microbial biomass nitrogen and dehydrogenase enzyme activity were higher after the incorporation of vermicompost [36]. All of this leads to the inference that the high concentration of applied bacteria but the low content of organic matter in the soil caused a lot of pressure in the microbial ecosystem, and it is presumed that immobilization was caused by them. In addition, vermicompost leachate may contain microbial populations indicative of an incomplete stabilization process, potentially posing phytotoxic or phytopathogenic risks.