A preliminary experiment was carried out to determine the 50%
effective concentration (EC50) values of the ILs using concentrations
of 0, 25, 50, 100, 200 and 400 mg kg1. [Demim]Cl, [Demim]Br and
[Demim]NO3 (4 g) were dissolved in 500 mL of deionized water,
and the appropriate amount of IL solutionwas then added to 1000 g
of soil. The soil was mixed sufficiently, and the moisture of the soil
was controlled at 60% by adding deionized water. The soil was
transferred into a pot, and three pots were used for each treatment.