水稻土镉形态分布特征及其生物效应研究.

Cadmium(Cd) in grains came from the soil. The form of cadmium in soil was closely related to the amount absorption of crops. The purpose of this paper was to find out the correlationship between the form of cadmium in soil and cadmium in grains, aimed to explore the source of cadmium in wheat/ rice grain, which provided theoretical basis for blocking-up cadmium absorption. Through investigating and sampling method, Cd content in paddy soil of tillage layer on Chengdu plain cadmium polluted area and the corresponding crop straw and grain were analyzed, which used to research the distribution characteristics and biological effects of different forms cadmium in these paddy soils. The results showed that the order of average content of different Cd forms in paddy soil was; O-FeMn > RE > EX > OM > CAB. The content distribution of different forms of Cd were extremely uneven, and the proportion of bio-available form was larger. There was a significant positive correlation between O-FeMn and pH, (r = 0. 712, P <0. 01) . The Cd content in wheat and rice were significantly positive correlated with wheat straw(r= 0.854* *, P< 0.01) and rice straw(r= 0.872* ", P<0.01) respectively. The EX-Cd in soil correlated with wheat straw and seed, respectively (r = 0.677 * and 0. 867 *, P < 0.01), but not other forms of Cd in soil. The EX-Cd content in soil was only correlated with Cd in rice grain (r = 0. 573 *, P <0. 05). The risk of Cd-exceed the standard in the grain of the crops which was grown on the polluted soil was high. [ABSTRACT FROM AUTHOR]