Achieving "remediating while producing" on arsenic contaminated soil by constructing interplanting systems based on...

Industrial activities have caused widespread arsenic (As) contamination in soil and medicinal crops across southern Asia. This study constructed interplanting systems combing medicinal crops with Pteris vittata L., aiming to mitigate the risk of As exposure in medicinal crops, while simultaneously achieving ecological remediation of contaminated soil. The results revealed that interplanting with P. vittata significantly enhanced the yield of Gynostemma pentaphyllum by 31.90 % (P < 0.05) compared with monoculture systems. Under monoculture conditions, the As concentration in G. pentaphyllum leaves reached 2.34 mg/kg, exceeding the national food safety standard (GB2762-2017, 2 mg/kg). However, interplanting with P. vittata effectively reduced the As concentration in G. pentaphyllum leaves to 1.82 mg/kg. Furthermore, the interplanting of P. vittata with Rhus chinensis significantly inhibited As translocation from belowground to aboveground tissues in R. chinensis. Compared to monoculture, the stem biomass of P. vittata was significantly increased by 57.50 % and 70.32 % when interplanted with G. pentaphyllum and Cassia obtusifolia L. (P < 0.05). So the As enrichment of P. vittata was enhanced in interplanting systems, which is beneficial for the As removal from contaminated soil. The study demonstrated that interplanting primarily regulates plant As uptake through modifications of rhizosphere physicochemical properties and As bioavailability, especially for water-soluble As that is easily absorbed by plants. In conclusion, the interplanting models integrating medicinal crops and P. vittata can achieve the goal of "remediating while producing" in As-contaminated soil.