Phytoremediation Potential of Native Plant Species in Naturally Boron-Enriched Saline-Alkaline Soils

This study investigates boron (B) accumulation trends in indigenous plant species naturally thriving in boron-enriched saline-alkaline soils in eastern Iğdır Plain, Türkiye. Soil and plant samples were collected from various geographical units, with a total of 19 paired surface soil (0-20 cm) and plant samples. Boron availability in soils and plant B concentrations were analyzed by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). The soil-plant relations were investigated through descriptive statistics, Pearson correlation, calculation of bio-concentration factors, and principal component analysis. The soils were also generally highly alkaline, with pH values ranging from 8.2 to 11.5, and characterized by salinity (EC values ranging from 2.70 to 12.2 dS/m) and elevated available B concentrations (from 14.1 to 89.8 mg/kg). The clay fraction was correlated with available soil-B, whereas other soil parameters displayed weak and non-significant correlations. Plant B concentrations varied considerably among species, ranging from 366 to 1225 mg/kg. High BCF values were observed in Alhagi (32.22) and Agropyron repens (21.12). PCA revealed that soil texture and salinity were the primary influencing factors, while chemical properties such as pH, calcium carbonate equivalent (CCE), and organic matter (OM) had minimal impact. Overall, several indigenous species demonstrated significant B tolerance and accumulation capacity. Alhagi and Agropyron repens emerged as potential B phytoextractors, whereas Atriplex nitens and Cynodon dactylon showed promise as B phytostabilizers.