DGT methodology is more sensitive than conventional extraction strategies in assessing amendment-induced soil cadmium availability to rice

Using diffusive gradients in thin films (DGT) is a recently developed alternativemethod of rapidly evaluating the bioavailability of metals in soil. However, the method has found only limited application in systematic assessment of the bioavailability of cadmium(Cd) in red limestone paddy soils treatedwith different soil amendments. Of the fourmethods compared for estimating Cd content of rice grains from plants grown in such soils of central China treated with eleven different soil amendments in pot culture, Cd content of DGT-labile soil was significantly correlated to Cd concentrations in brown rice (R = 0.447, p < 0.01). The other three methods involved CaCl2, diethylenetriaminepentaacetic acid (DTPA), or NH4NO3. Some other properties of soil, such as pH, redox potential, content of dissolved organic matter, and cation exchange capacity were also determined. A simple algorithm developed to evaluate the sensitivity of the four methods also confirmed DGT as the most efficient method to predict the bioavailability of Cd in red limestone paddy soils. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The study found that the DGT method performed the best in assessing the bioavailability of Cd in red limestone paddy soils, effectively predicting the Cd content in brown rice. Additionally, the study compared three other methods and confirmed DGT as the most efficient method for this purpose.