Thiosulphate-induced mercury accumulation by plants: metal uptake and transformation of mercury fractionation in soil - results from a field study

• Published in: Plant and soil 2014-02, Vol.375 (1-2), p.21-33
• Main Authors: Wang, Jianxu, Feng, Xinbin, Anderson, Christopher W. N, Wang, Heng, Wang, Lulu
• Format: Article
• Language: English
• Subjects: Acid soils; Agricultural land; Agricultural research; Agricultural soils; Agrology; Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Bioavailability; Biological and medical sciences; Biomedical and Life Sciences; Brassica juncea; Brassica napus var. napus; Chemical properties; crops; Cultivars; Ecology; Environmental aspects; Environmental risk; Experimental farms; Field study; Flowers & plants; Fractionation; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; harvesting; iron; Life Sciences; manganese; Mercury; Metal concentrations; Metals; Organic soils; Phytoremediation; Plant Physiology; Plant Sciences; Plant-soil relationships; planting; Plants; Regular Article; Rhizosphere; risk; Root zone; shoots; Soil pollution; Soil profiles; Soil science; Soil Science & Conservation; soil treatment; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Soils; Thiosulfates; Vertical distribution
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-013-1940-5

AIMS: The thiosulphate induced accumulation of mercury by the three plants Brassica juncea var.LDZY, Brassica juncea var.ASKYC and Brassica napus var. ZYYC and the transformation of mercury fractionation in the rhizosphere of each plant was investigated in the field. METHODS: Experimental farmland was divided into control and thiosulphate plots. Each plot was divided into three subplots with each planted with one of the plants. After harvesting, the mercury concentration in plants, mercury fractionation in rhizosphere soil before and after phytoextraction, and the vertical distribution of bioavailable mercury in bulk soil profiles was analyzed. RESULTS: The cultivar B. juncea var.LDZY accumulated a higher amount of mercury in shoots than the other two plants. Thiosulphate treatment promoted an increase in the concentration of metal in plants and a transformation of Fe/Mn oxide-bound and organic-bound mercury (potential bioavailable fractions) into soluble and exchangeable and specifically-sorbed fractions in the rhizosphere. The observed increase in bioavailable rhizosphere mercury concentration was restricted to the root zone; mercury did not move down the soil profile as a function of thiosulphate application to soil. CONCLUSIONS: Thiosulphate-induced phytoextraction has the potential to manage environmental risk of mercury in soil by decreasing the concentration of mercury associated with potential bioavailable fraction that can be accumulated by crop plants.