Phyto-available concentration of cadmium (Cd) is considered a good indicator for the assessment of
environmental quality of Cd contaminated soils and is more important than total metal contents in soil. A pot study
was conducted using two different textured soils, collected from raw sewage irrigated areas of the Faisalabad.
The extraction efficiency of extractants for phyto-available Cd from soils was compared. Phyto-available Cd was
correlated to Cd concentrations in shoots and grains of rice (cv. Basmati-2000). Cadmium chloride salt was used
@ 20 mg Cd kg-1 of soil to impregnate these soils and was allowed to equilibrate for 30 days at moisture level of
about field capacity. Chemicals viz. AB-DTPA, 0.005 M DTPA, 0.05 M EDTA, 0.01 M CaCl2, 1 M NH4NO3 and 0.1
M NaNO3 were used to extract Cd and its concentration was determined with atomic absorption
spectrophotometer. Correlation analysis between the extractable and plant Cd concentration determined by diacid
method was performed. The AB-DTPA extractable Cd had more positive and significant correlation with Cd
concentration in rice straw and grains harvested from sandy clay loam soil than the other extractants under
test. For loamy sand, maximum correlation of Cd concentration in rice straw was recorded with NaNO3-Cd
while in grains it was maximum with ABDTPA-Cd. Overall, AB-DTPA gave better and comparable results
than those with other extractants and neutral salts gave good results for light textured calcareous soil. It
seems important that future research may focus to investigate the effect of soil properties and plant species
as variables to assess the efficiency of extractants.
Muhammad Zia-ur-Rehman, Abdul Ghafoor, Muhammad Sabir, Saifullah, Asif Naeem, Hamaad Raza Ahmad . (2008) Extractants for the assessment of phyto-available cadmium to rice grown in cadmium contaminated soils, , Volume-45, Issue-1.
