Cadmium (Cd) levels in paddy fields across Taiwan have increased due to emission from industry. To
ensure the production of rice that meets food quality standards, predictive models or suitable soil tests
are needed to evaluate the quality of soils to be used for rice cropping. Levels of Cd in soil and rice grains
were measured in 19 paddy fields across the western plains in Taiwan. Cadmium levels in soil range
from less than 0.1 mg kg1 to 30 mg kg1. Measured Cd levels in brown rice were predicted very well
(R2 > 0.8) based on Cd and Zinc in a 0.01 M CaCl2 extract or a soil–plant transfer model using the
reactive soil Cd content, pH, and cation exchange capacity. In contrast to current soil quality standards
used in Taiwan, such models are effective in identifying soils where Cd in rice will exceed food quality
standards.