Abstract: The low bioavailability of mercury (Hg) in Hg-polluted soil limits the application of phytoremediation. In this paper, a greenhouse pot experiment was conducted to study the effects of ammonium thiosulphate amendment on the Hg-bioavailability in soil, the Indian mustard biomass, and the Hg uptake by the plant. When the amended ammonium thosulphate was 1/12.5 of soil (W/W), the concentration of soil bioavailable Hg was the highest (0.51 mg·kg^-1), 12.7 times of the control. When the ammonium thosulphate was amended at a rate of 2 g·kg^-1, the dry weight of mustard root, stem, and leaf increased by 0.23, 0.98, and 1.22 g, and the Hg concentration in the root, stem and leaf was 1.96, 0.43, and 3.35 mg·kg^-1, being 8, 4, and 2 times of the control, respectively. Amendment of ammonium thiosulphate increased the leachate Hg concentration, with the maximum as high as 2487 ng·L^-1. Therefore, the amendment of ammonium thiosulphate to Hg-contaminated soil could increase the efficiency of phytoremediation, but on certain conditions, could also cause Hg-leaching into underground.

Key words: Nutritional resource, Anagrus nilaparvatae, Longevity, Parasitic ability, Survival rate