天然有机酸对伴矿景天吸取土壤镉的影响

Effects of natural organic acids on cadmium uptake by Sedum plumbizincicola from the soil

采用田间试验,研究了穴/喷施低、中、高剂量苹果酸、柠檬酸等天然有机酸对伴矿景天修复偏酸性Cd污染土壤及地上部吸取量的影响,并筛选出天然有机酸最佳施用模式.结果表明:与对照相比,穴/喷施天然有机酸处理0~30d后均能有效降低了土壤pH值,提高了土壤有效态Cd含量,60d后伴矿景天地上部生物量和Cd含量均有效提高.综合评价,喷施低浓度柠檬酸效果最好,与对照相比,10d后土壤pH值降低了0.32个单位,土壤有效态Cd提高了29.4%;60d后伴矿景天地上部生物量提高了38.6%,地上部Cd含量提高了30.7%,地上部Cd吸取量提高了81.7%.研究表明,穴/喷施苹果酸和柠檬酸均是辅助伴矿景天修复偏酸性Cd污染农田土壤的有效办法,筛选出的最佳施用模式为每公顷喷施75kg柠檬酸.

Field experiments were conducted to study the effects of low,medium and high doses of natural organic acids(malic acid and citric acid)using hole or spray application on the remediation of slightly acidic Cadmium(Cd)contaminated soil and the Cd accumulation in shoots of Sedum plumbizincicola,Then the best application pattern of natural organic acid was determined.Results showed that compared with the control,the hole/spray application of natural organic acid for 0~30d significantly reduced the soil pH value and increased available Cd concentrations in soil.The shoot biomass and Cd concentration in shoot of S.plumbizincicola were significantly increased after 60d.Spray application of low concentration citric acid is proved to be the best pattern.Compared with the control,the soil pH value decreased by 0.32 units and soil available Cd increased by 29.4%after 10d.After 60d,the shoot biomass of S.plumbizincicola increased by 38.6%,the shoot Cd content increased by 30.7%,and the shoot Cd extraction increased by 81.7%.The results showed that both malic acid and citric acid using hole/spray application were effective methods to assist S.plumbizincicola in the remediation of acidic Cd contaminated farmland soil,and the optimal application pattern was 75kg citric acid sprayed per hectare.