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Chinese Agricultural Science Bulletin ›› 2023, Vol. 39 ›› Issue (14): 41-47.doi: 10.11924/j.issn.1000-6850.casb2022-0498

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Comparative Study on Remediation of Slight and Moderate Cadmium Contaminated Paddy Fields by Energy Sorghum (Sorghum bicolor L.)

LI Baizhong(), HUANG Daoyou, XU Chao(), ZHU Hanhua, ZHANG Quan   

  1. Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125
  • Received:2022-06-13 Revised:2022-09-18 Online:2023-05-09 Published:2023-05-09

Abstract:

To clarify the remediation ability of energy sorghum in paddy fields, five energy sorghum varieties were used to carry out phytoremediation comparative experiments in paddy fields with slight and moderate cadmium (Cd) contamination. The Cd accumulation amount, enrichment coefficient, transfer coefficient and the soil Cd concentration change were measured, the correlation among these indexes were analyzed. The results showed that in slightly Cd contaminated paddy field (the total Cd concentration of soil was 0.59 mg/kg), the shoot Cd accumulation of five energy sorghum varieties was 13.62-34.70 g/hm2, the enrichment coefficient was 1.53-3.38, and the transfer coefficient was 0.25-0.68. The shoot Cd accumulation of ‘Alto 2’ (V4) was significantly higher than that of ‘Alto 601’ (V1), ‘Alto 901’ (V2) and ‘Alto 1’ (V3) by 154.71%, 64.90% and 30.68%, respectively. The shoot Cd accumulation of V3 and ‘N51M4264’ (V5) was significantly higher than that of V1 by 94.89% and 141.42%, respectively. In moderately Cd contaminated paddy field (the total Cd concentration of soil was 1.89 mg/kg), the shoot Cd accumulation of the five energy sorghum varieties was 14.78-53.35 g/hm2, the enrichment coefficient was 0.72-1.65, and the transfer coefficient was 0.24-0.43. In addition, the shoot Cd concentration of V3, V4 and V5 were significantly higher than that of V1 and V2 by 148.26%-260.98%. The enrichment coefficient was significantly and positively correlated with the transfer coefficient (P<0.01), but was negatively correlated with soil total Cd and soil available Cd concentration (P<0.05). The results showed that all the five energy sorghum varieties had better biological yield. ‘Alto2’ could be used for the remediation for moderately Cd contaminated paddy fields because of its higher biological yield, and good enrichment and transfer capacity. ‘Alto 601’ could be used for the safe production in slightly Cd contaminated paddy fields because of its relatively low Cd enrichment and transfer capacity.

Key words: Cd contaminated paddy fields, energy sorghum, phytoremediation, safe production, enrichment coefficient