The effect of liming on the physiological characteristics and Cd(II) absorption of japonica and indica rice cultivars grown in a Cd(II) contaminated paddy soil

To investigate the impact of liming on Cd(II) absorption and the growth of japonica and indica rice cultivars grown in paddy soil contaminated with Cd(II).

A pot experiment was done to investigate the impact of liming on the growth of rice and the absorption of Cd(II) by various rice cultivars grown in Cd(II) contaminated soil, with and without the addition of lime.

In all types of rice, Cd(II) sensitive rice cultivars exhibit a greater capacity to adsorb exchangeable, complexed, and precipitated forms of Cd(II) compared to Cd(II) tolerant rice cultivars. Indica rice cultivars generally had higher quantities of Cd(II) exchangeable forms than japonica rice variants. These rice types showed similar patterns in Cd(II) absorption of their roots. Lime application in Cd(II) polluted soil decreased the availability of Cd(II) in the soil. This, in turn, led to a reduction in the Cd(II) uptake and distribution in all components of rice plants. The indica rice cultivars exhibited greater roots and shoots dry weight compared to the japonica rice cultivars. Lime increased the plant biomass in all the rice cultivars. In lime-treated soil, the pot grains weight was highly increased in both types of rice, while favorably enhancing all the yield contributing indicators, particularly in Cd(II) sensitive rice cultivars.

The application of lime in Cd(II) polluted soil can decrease the availability of Cd(II) in the soil, thereby reducing the Cd(II) uptake by rice plants, and increasing the nutrient uptake capacity of rice, thereby increasing the yield components of rice plants.