Organic amendments improved soil properties and native plants’ performance in an Australian degraded land

Context Land degradation poses a substantial threat to both the sustainable environment and human health. Efforts towards rehabilitation and remediation often require addition of soil amendments and careful selection of plant species. Aims We assessed the effect of recycled organic amendments on improvement of soil physicochemical properties and performance of native plant species in an Australian degraded soil. Methods A glasshouse pot experiment investigated the effects of compost (CO), biochar (BC), and compost-biochar (COBC) mixture on performance of three native Australian plant species (Eucalyptus tereticornis (EU), Acacia leiocalyx (AC), and Banksia integrifolia (BA)) in a degraded soil. Key results Application of CO, BC, and COBC organic amendments increased soil dissolved organic carbon and microbial biomass carbon contents compared to the control treatment. COBC amendment increased nutrient retention and reduced CO2 emissions compared to CO amendment. BC amendment also resulted in low CO2 emissions similar to the control treatment, where no significant differences were observed. AC outperformed the EU and BA species in biomass production due to its leguminous nature, with amendment application had an insignificant effect on AC performance. Within the EU treatments, the COBC:EU demonstrated the highest biomass production, followed by CO:EU, BC:EU, and CK:EU, respectively. Conclusion All amendments exhibited overall improvements in soil and plant parameters, with more significant outcomes observed with COBC application. However, the observed improvements from biochar application were minimal in this short-term experiment, which may not have allowed for the manifestation of long-term benefits. Implications Further research is warranted to investigate the effects of compost and biochar amendments on diverse soil types and native plant species.