Remediation efficacy of Sedum plumbizincicola as affected by intercropping of landscape plants and oxalic acid in urban cadmium contaminated soil
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Intercropping is a promising technique for remediation of soils contaminated with heavy metals. Organic acids can increase the availability of heavy metals in soil. Our aim was to assess the effect of oxalic acid as an activator for hyperaccumulator–landscape plant intercropping to efficiently restore contaminated soil with low cost.
Materials and methods
The hyperaccumulator plant (Sedum plumbizincicola) was intercropped with selected landscape plants: Oxalis corniculate (ground cover plant), Calendula officinalis (grass flower plant), and Buxus sinica (shrub). The effects of 11 mmol kg−1 oxalic acid treatment on growth and Cd accumulation capacity of Sedum plumbizincicola–landscape plants intercropping systems were evaluated in a 76-day pot experiment.
Results and discussion
Oxalic acid has increased the availability of Cd in soil. The biomass of Sedum, Oxalis, and Buxus plants was higher in treatment of oxalic acid than without oxalic acid. The biomass, chlorophyll, and catalase contents of Calendula were lower in treatment of oxalic acid than without oxalic acid, which indicated severe stress caused by enhanced availability of Cd. The malondialdehyde contents of Calendula and Buxus were higher in treatment of oxalic acid, which indicates that higher Cd availability has resulted damage of membrane. The free proline contents of Calendula and Buxus were higher in treatment of oxalic acid. The Cd content of Sedum plants was higher in treatment of oxalic acid than lower Cd in landscape plants with no application of oxalic acid.
It is concluded that oxalic acid has a positive effect on remediation efficiency of Sedum plumbizincicola-Oxalis and Sedum plumbizincicola-Buxus intercropping systems. Oxalic acid has enhanced remediation efficiency of hyperaccumulator-landscape plants intercropping which has offered a new, useful and practical technique for remediation of urban soils with low-level Cd contamination.
KeywordsHeavy metal Intercropping Landscape plants Oxalic acid Sedum plumbizincicola
The study was financially supported through a grant from the Natural Science Foundation of China (31670617, 21876027, and 21577131), New Shoot Talented Plan of Zhejiang Province (2017R412039), and key research and development project of Science Technology Department of Zhejiang Province (2015C03020-2).
- Bao J, Wei HQ, Zhao XL (2012) Feasibility of low molecular weight organic acids in enhancing phytoextraction of cadmium from soils with tobacco (Nicotiana tabacum L.). J Soil Water Conserv 26(2):265–270 (in Chinese) Google Scholar
- Ferhad M, Muttalip G, Sezai E, Tarik E, Fikri B, Hawa ZEJ, Muhammad ZUH (2015) Cadmium toxicity affects chlorophyll a and b content, antioxidant enzyme activities and mineral nutrient accumulation in strawberry. Biol Res 48(1):11Google Scholar
- Gao W, Wei H, Jia ZM, Tian XF (2012) Photosynthesis response to cadmium in Vetiveria zizanioides (L.) Nash. Journal of Southwest China Normal University 37(10):59–64 (in Chinese)Google Scholar
- Lai CX, Pan WB, Zhang TP et al (2016) Effects of malic acid and oxalic acid application on the uptake of Cd and Zn by two plants. Ecol Sci 35(4):31–37 (in Chinese) Google Scholar
- Lu KP, Yang X, Gielen G, Bolan N, Ok YS, Niazi NK, Xu S, Yuan G, Chen X, Zhang X, Liu D, Song Z, Liu X, Wang H (2017) Effect of bamboo and rice straw biochars on the mobility and redistribution of heavy metals (Cd, Cu, Pb and Zn) in contaminated soil. J Environ Manag 186:285–292CrossRefGoogle Scholar
- Meng ZF, Zhang YM, Deng J (2011) Effects of oxalic acid on the adsorption and interaction of Cd2+, Zn2+ in different soils. J Agro-Environ Sci 30(11):2265–2270 (in Chinese) Google Scholar
- Qin L (2017) Accumulation characteristics of Cd, Pb and the root secretion mechanism of low molecular organic acids in Sonchus asper and crop intercropping system. Yunnan Agricultural University, Yunnan, China, Doctoral Thesis (in Chinese) Google Scholar
- Qin L, Zu YQ, Zhan FD et al (2013) Absorption and accumulation of Cd by Sonchus asper L.Hill. and maize in intercropping systems. J Agro-Environ Sci 32(03):471–477 (in Chinese) Google Scholar
- Xu WJ, Guo J, Zhao M, Wang RY, Hou SZ, Yang Y, Zhong Bin, Guo H, Liu C, Shen Y, Liu D (2017) Research progress of soil plant root exudates in heavy metal contaminated soil. Journal of Zhejiang A & F University 34(6):1137–1148 (in Chinese) Google Scholar