This study aimed to investigate the impact of Rekulter, a lignite-based fertilizer, on various soil parameters, with a focus on promoting sustainable agricultural practices. A multi-year field trial was conducted in Klon, Poland, employing potentiometric techniques, spectrophotometry, and gas chromatography-mass spectrometry to analyze soil samples. Established laboratory procedures were used to assess pH value, sorption properties, granulometric composition, organic carbon content (OC), total nitrogen (TN), polycyclic aromatic hydrocarbons (PAHs), phenolic compounds (PCs), and the fractional composition of organic matter. Hypothesis-driven experiments, including Analysis of Variance (ANOVA) and Tukey’s HSD post hoc tests, were utilized to examine the effects of Rekulter application on soil characteristics. Significant differences were found in organic carbon (OC), total nitrogen (TN), polycyclic aromatic hydrocarbons (PAHs), phenolic compounds (PCs), and fractional organic matter composition among the Rekulter variants. This study underscores the dose-dependent effects of Rekulter on soil properties and provides insights into optimizing application rates for sustainable soil management. Recommendations include tailoring agricultural interventions based on soil characteristics and environmental considerations, integrating organic amendments with mineral fertilizers, and promoting balanced approaches to reclamation. This research contributes to ongoing efforts to improve agricultural sustainability and mitigate environmental impacts, guiding practices that balance productivity with environmental stewardship.