Objective  The aims were to study the dynamic uptake and transport characteristics of cadmium (Cd) within rice in different soils.

  Method  Slightly to moderately Cd-contaminated paddy soils including reddish sandy soil (Typic Fe-accumulic-Stagnic Anthrosols) and slurry soil (Typic Fe-leachi-Stagnic Anthrosols) in China were selected to plant rice through a pot experiment. Rice plants were sampled respectively at the seedling, mid-tillering, mid-booting, and mature stages for the determination of Cd accumulation in different tissues.

  Result  The results showed that the CaCl₂-extractable Cd concentration (0.02 mg kg⁻¹) in the slurry soil was 86.7% lower than that in the reddish sandy soil (0.15 mg kg⁻¹). Thus, the average accumulation rate of Cd in the slurry soil (0.09 μg plant⁻¹ d⁻¹) during the seedling to mid-tillering period was 71.9% lower than that in the reddish sandy soil (0.32 μg plant⁻¹ d⁻¹), while the average accumulation rate of Cd in the slurry soil (0.038 μg plant⁻¹ d⁻¹) was 47.9% lower than that in the reddish sandy soil (0.073 μg plant⁻¹ d⁻¹) during the mid-tillering to booting period, indicating the seedling to mid-tillering stage was the key period for soil types to affect Cd accumulation in rice. At the mature stage, the distribution rate of Cd in brown rice in the reddish sandy soil (11.0%) was lower than that in the slurry soil (16.6%). Furthermore, the Cd amounts in mature rice were reduced in both two soils, and the reduction rate in the red sandy soil (28.9%) was higher than that in the slurry soil (18.2%). As a result, Cd amount of brown rice in the slurry soil was 44.4% lower than that in the reddish sandy soil.

  Conclusion  This study indicates that soil differences influence not only the Cd availability in soil and uptake by rice but also the transport of Cd within rice plant, and further regulate Cd concentration in brown rice.