Tolerance to Copper Stress in Biomass Crops Elephant grass, Vetiver grass and Upland reed under Soil Culture

摘要

Elephant grass(EG), Vetiver grass(VG) and Upland reed(UR) are probably used as biomass crops, and all of them have strong adaptability in some stress circumstance, such as under heavy metal stress, which makes it possible to introduce them to the copper polluted areas. The experiment was conducted in plastic pots by simulating pollution. The work indicated that the toxity of copper to the plants EG, VG and UR had a positive correlation to the total and bio-available concentrations in the soil. But all the three plants also showed strong tolerance and adaptability to the copper stress. Based on the EC_(50) value , Dry weight , Cu contents and chlorophyll contents in leaves of the three plants, the tolerant ability of them ranked as: EG>VG>UR. The unit calorific value of the plants were detected as: EG, 13281.39-13798.13J/g; VG, 14071.33-14959.68 J/g and UR, 14049.28- 14590.39J/g. The total calorific value of EG was higher than VG and UR and was determined mainly by the biomass (dry weight) . The amendment KH_2PO_4 effectively decreased the bioavailability of Cu or Cu uptake by plants, and the fresh weight was positively relative to the remission of the phosphate. The EG may be the best candidate to be introduced in the copper contaminated soils ( about 1500mgCu/kg soil ) improved by some amendments for biomass production among the three plants.