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Paddy fields contaminated by Cd in Taiwan need to be more concerned. High concentration of Cd in rice grains is harmful to human health. Cd-contaminated fields are often abandoned or being changed to plant non-edible crops. It is urgent to restore the contaminated environment due to limited nature resources. This research selects conservation grasses including Bermuda grass, Carpet grass, Carpet grass(Axonopus affinis Chase), Centipede grass, Bahia grass, Japanese silver grass etc. Every grass treated with different concentrations of Cd and then survey growth of grasses. The purpose of this paper is to find the suitable conservation grass for the reclamation of Cd- contaminated soils and establish the data base of conservation grass for the use of Cd-contaminated soils. The results are summarized as follows:Germination percentage for tested grasses are not affected by the concentration of Cd. Tested grasses are all showing the same symptoms of toxicity at the 50ppm treatment of Cd concentration. Stunted growth, chlorosis and undeveloped root systems are the major symptoms and can be identified obviously at high concentration of Cd added. Plant height, root length, and dry weight of grasses are decreased significantly by increasing Cd concentration. High Cd concentration results in poor nutrients uptake and stunted growth for tested grasses except Bermuda grass. Bermuda grass shows no significant difference on nutrients uptake but Mn and Zn under Cd treatment. Increasing Cd concentration inhibits Mn-uptake, while enhances Zn-uptake for Bermuda grass tissue. Comparing to Bermuda grass and Centipede grass, Carpet grass, Carpet grass(Axonopus affinis Chase), Bahia grass, and Japanese silver grass showed worse tolerance to Cd-contamiinated soils. Bermuda grass and Centipede grass show no significant difference in growth among the Cd- contaminated levels and both have good ability to absorb Cd element from the soils. Both of them can be as the suitable grasses (especially Bermuda grass) for the use of restoration of Cd-contaminated soils.
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