TITLE:
Groundwater Level Effect on Redox Potential, on Cadmium Uptake and Yield of Soybean
AUTHORS:
Md. Zahidul Haque, Choichi Sasaki, Nobuhiko Matsuyama, Takeyuki Annaka, Chihiro Kato
KEYWORDS:
Groundwater Level, Redox Potential (Eh), Cadmium Uptake, Soybean Seed Yield
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.5 No.20,
September
26,
2014
ABSTRACT: In this greenhouse experiment, we investigated the effects of two
constant groundwater levels: 10 cm groundwater level (GW-10) and 40 cm
groundwater level (GW-40) and one change groundwater level, which was 40-10-40 cm
(GW-40-10-40) on Cadmium (Cd) uptake and seed yield of Soybean plant in Cd
contaminated soils (1.57 mg·kg-1).
The experimental soil layer was made with gravel layer (14 cm), non-polluted
soil (15 cm) and polluted soil (25 cm). The redox potential of every soil layer
was measured from sowing to harvesting. The soil layer (10 – 40 cm) of GW-10
was always in reduction condition and that of GW-40 was always in oxidation
condition. First 50 days of GW 40-10-40 were in oxidation and next 50 days in
reduction and final 20 days again returned in oxidation condition. Soybean seed
Cd concentration was significantly highest in GW-40-10-40 (1.16 ± 0.13 mg·kg-1)
and lowest in GW-40 (0.81 ± 0.12 mg·kg-1). Cd concentration of stem
was found significantly higher in GW-40 (1.7 ± 0.2 mg·kg-1) than
GW-10 (0.91 ± 0.08 mg·kg-1) and GW-40-10-40 (1.28 ± 0.13 mg·kg-1).
There was no significant difference in root Cd concentration among these 3
treatments. Main stem height of soybean plant and 100 seed weight of GW-40 were
significantly higher than those of GW-10. The result revealed that, soil redox
condition is an important factor for Cd uptake in soybean plant and seed yield
of soybean. This study will help to manage the farming process more
appropriately with the aim of minimizing uptake of Cd and other toxic metals in
grain crops.