PurposeThe 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 Kochia prostrata remains unclear. This study, conducted in a semi-arid rangeland in northern Iran, involved planting K. prostrata along with soil amendments.MethodsThe efficacy of biochar and modified chitosan amendments, applied singly and in combination at different dosages, in promoting K. prostrata 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 Azolla filiculoides-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).ResultsOur 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.ConclusionBiochar 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.