[Phytotoxic effect of soil cadmium pollution on ramie]

A microplot locating experiment was conducted to study the phytotoxic effect of adding Cd in soil on ramie plants. The results showed that the contents of chlorophyll a and b of leaf, and the photosynthesis productivity of ramie plant were significant reduced by the addition of Cd. As the content of soil Cd reached to 14 mg.kg-1, the biomass yield of the above-ground part of ramie plants was 20% lower than the control, and was 50% lower when soil Cd content was at 100 mg.kg-1. The number of effective tillers was a main factor affecting the yield of ramie raw fibers, and Cd addition had a relatively small effect on the quality of raime fibers. It is suggested that a synthetical technology of soil treatment and agronomic measures should be applied to eliminate the toxic effect of soil Cd and to enhance the resistance of plant against soil Cd pollution when employing ramie as the alternative of food and vegetable crops in a Cd-polluted region, which is also important for a higher yield of ramie.