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Effects of ground granulated blast-furnace slag (GGBS) on hydrological responses of Cd-contaminated soil planted with a herbal medicinal plant (Pinellia ternata)

Authors Ng, Charles Wang Wai; Chowdhury, Nilufar; Wong, James Tsz Fung

Journal CANADIAN GEOTECHNICAL JOURNAL , MAY 2020,5:57

DOI 10.1139/cgj-2018-0868

Abstract Pinellia ternata is a medicinal herb often contaminated by cadmium (Cd), which inhibits its growth and metabolism. In this study, ground granulated blast-furnace slag (GGBS) is proposed as a soil amendment to reduce plant Cd availability and therefore increase transpiration-induced suction. Field soil (silty gravelly sand) contaminated with 1.5 mg.kg(-1) of Cd was collected from Guizhou, China. The growth of P. ternata in 0%, 3%, and 5% GGBS amended soil has been investigated in a temperature- and humidity-controlled chamber. Soil amended with 3% and 5% GGBS significantly (P < 0.05, where P is probability) increased leaf area index (LAI) by 29% and 30%, root area index (RAI) by 65% and 66%, respectively, compared to untreated soil (control). Soil suction was significantly (P < 0.05) increased by 58% in soils amended with 3% and 5% GGBS. Compared to the control, soil amended with 3% and 5% GGBS has exhibited higher air-entry value (AEV) and higher water retention ability. The study revealed that addition of GGBS increased soil water availability for plant growth. This implies that to achieve statistically significant improvement in P. ternata growth and soil hydrological responses 3% GGBS should be applied in Cd-contaminated soil.

Species covered 半夏 Pinellia ternata