Purpose <p>The use of natural-based soil amendments has garnered significant attention as an emerging technology in natural resources management. However, the impact of these amendments on the performance of the rangeland species <i>Kochia prostrata</i> remains unclear. This study, conducted in a semi-arid rangeland in northern Iran, involved planting <i>K. prostrata</i> along with soil amendments.</p> Methods <p>The efficacy of biochar and modified chitosan amendments, applied singly and in combination at different dosages, in promoting <i>K. prostrata</i> growth and improving soil properties was evaluated. A field experiment was conducted over a twenty-two months period to assess the impact of varying concentrations of <i>Azolla filiculoides</i>-derived biochar (0%, 0.2%, 0.6%, and 1.2%) and modified chitosan (0%, 0.01%, 0.05%, and 0.1%) when applied to soil pits under natural conditions. In total, the experiment involved digging 48 pits in the field (a factorial design with 4 levels of biochar, 4 levels of chitosan, and 3 replications).</p> Results <p>Our results showed that plants grown in pits with 1.2% biochar exhibited a 3- to 3.5-fold increase in root and plant dry weight compared to the control (without biochar treatment). The chitosan-modified treatment of 0.1% significantly increased root biomass by 75%, specific leaf area by 140%, and plant height by 57%. Adding the highest dose of biochar and modified chitosan (1.2% and 0.1%, respectively) to the soil increased soil carbon by 40–45% compared to the control samples.</p> Conclusion <p>Biochar and modified chitosan effectively manage degraded rangeland in arid and semi-arid regions. This study provides insights into the potential role of chitosan and biochar in improving restoration efforts.</p>