Practical phytoextraction in cadmium-polluted paddy fields using a high cadmium accumulating rice plant cultured by early drainage of irrigation water
Article first published online: 28 MAY 2009
© 2009 Japanese Society of Soil Science and Plant Nutrition
Soil Science & Plant Nutrition
Volume 55, Issue 3, pages 421–427, June 2009
How to Cite
IBARAKI, T., KUROYANAGI, N. and MURAKAMI, M. (2009), Practical phytoextraction in cadmium-polluted paddy fields using a high cadmium accumulating rice plant cultured by early drainage of irrigation water. Soil Science & Plant Nutrition, 55: 421–427. doi: 10.1111/j.1747-0765.2009.00367.x
- Issue published online: 28 MAY 2009
- Article first published online: 28 MAY 2009
- Received 3 July 2008.Accepted for publication 25 January 2009.
- cadmium-polluted paddy fields;
- indica rice variety;
- water management
Some indica rice varieties are potential phytoextractors for paddy fields polluted with Cd because of their high biomass and because they can accumulate Cd to moderate levels in their shoots. To establish a practical phytoextraction system, phytoextraction using two indica rice cultivars (MORETSU and IR-8) was carried out in a paddy field polluted with moderate Cd levels (2.91 and 2.52 mg kg−1, respectively). The Cd concentration and Cd uptake of MORETSU increased when irrigation water was drained at the maximum tillering stage, and the paddy soil was under oxidative conditions until harvesting. The Cd uptake of MORETSU and IR-8 increased and reached 516 and 657 g ha−1, respectively, at the beginning of October. After phytoextraction using these high Cd accumulating rice varieties for 2 years, the Cd concentration in the paddy field decreased by 18% compared with the initial Cd concentration. The Cd concentration in the rice grains of a japonica ordinary rice variety (HINOHIKARI) subsequently grown on the field after the phytoextraction was lower than the concentration in rice grown on a non-phytoextracted field. These results suggest that phytoextraction using high Cd accumulating rice varieties with early drainage of irrigation water is a practical remediation system for moderate Cd polluted paddy fields in southwest Japan.