Remediation effect and mechanism of low-As-accumulating maize and peanut intercropping for safe-utilization of As-contaminated soil

摘要

NOVELTY STATEMENTPhytoremediation by intercropping is a potential method to realize both production and remediation. Maize and peanuts are the main crops planted in As-contaminated areas and easily polluted by As. This study preliminarily demonstrated the feasibility of this intercropping system to safely use and remedy arsenic-contaminated farmland during production. @@@ Phytoremediation by intercropping is a potential method to realize both production and remediation. Maize and peanut are the main crops planted in arsenic(As) contaminated areas in south China and vulnerable to As pollution. Experiments were conducted on arsenic-polluted soil with low As-accumulating maize monoculture (M), peanut monoculture (P), and intercropping with different distances between the maize and peanut (0.2 m, 0.35 m, and 0.5 m, recorded as MP0.2, MP0.35, and MP0.5, respectively). The results indicated that the As content in the maize grains and peanut lipids in the intercropping system decreased significantly, meeting the food safety standard of China (GB 2762-2017). Moreover, the land equivalent ratio (LER) and heavy metal removal equivalence ratio (MRER) of all intercropping treatments were greater than 1, indicating that this intercropping agrosystem has the advantage of production and arsenic removal, among which the yield and LER of MP0.35 treatment were the highest. Additionally, the bioconcentration factors (BCF) and translocation factor (TF) of MP0.2 increased by 117.95% and 16.89%, respectively, indicating that the root interaction affected the absorption of As in soil by crops. This study preliminarily demonstrated the feasibility of this intercropping system to safely use and remedy arsenic-contaminated farmland during production.

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