不同结构改良剂对铜镉污染土壤水稻生长和重金属吸收的影响

本研究以铜（Cu）、镉（Cd）污染水稻土为对象，通过水稻盆栽试验研究聚丙烯酸（PAA）、聚丙烯酰胺（PAM）、聚乙烯醇（PVA）和腐殖酸（HA）这4种结构改良剂对水稻生长和重金属吸收的影响.结果表明，与对照处理相比，施用结构改良剂处理水稻株高和秸秆重分别增加了7.34%~22.0%和10.0%~32.2%，结构改良剂用量越高，增幅越大.施用0.4%的结构改良剂对水稻有一定的减产效应，籽粒重比对照处理降低了6.70%~32.6%.施用结构改良剂对土壤pH值无影响，但显著降低了土壤有效态Cu （5.38%~39.7%）和Cd含量（6.98%~59.6%），水稻根、秸秆和稻米中Cu含量分别降低了0.88%~27.2%、8.50%~45.2%和3.41%~31.2%，Cd含量分别降低了5.93%~20.5%、10.0%~51.4%和3.12%~50.7%，PAA处理的降幅最大、PVA处理的降幅最小.结构改良剂降低了Cu和Cd从根系向秸秆的转运系数，但增加了Cu和Cd从秸秆向稻米的转运系数.总体来看，施用结构改良剂促进了水稻生长，抑制了水稻对Cu和Cd的吸收，对重金属污染土壤具有一定的修复效果.

Effects of Different Soil Conditioners on Rice Growth and Heavy Metal Uptake in Soil Contaminated with Copper and Cadmium

A rice pot experiment was conducted to study the effects of four soil conditioners, namely polyacrylic acid (PAA), polyacrylamide (PAM), polyvinyl alcohol (PVA), and humic acid (HA), on rice growth and heavy metal uptake from paddy soil contaminated with copper and cadmium. The results showed that the height and straw weight of rice in the conditioned soil treatments increased by 7.34%-22.0% and 10.0%-32.2%, respectively, compared to the control treatment. The increased height and straw weight was generally proportional to the amount of soil conditioners used in each treatment. Application of 0.4% soil conditioners led to a slight reduction in rice yield, with the grain weight decreasing by 6.70%-32.6% relative to the control treatment. Soil conditioners had no effect on soil pH, but significantly reduced the concentration of soil available Cu (5.38%-39.7%) and Cd (6.98%-59.6%). Similarly, concentrations of Cu in rice root, straw, and grain were decreased by 0.88%-27.2%, 8.50%-45.2%, and 3.41%-31.2%, respectively, while concentrations of Cd were decreased by 5.93%-20.5%, 10.0%-51.4%, and 3.12%-50.7%, respectively. The largest and smallest decreases occurred in the PAA and PVA treatments, respectively. Application of PAA, PAM, and HA significantly decreased the translocation factor of Cu from root to straw by 11.2%-27.1%, whereas the translocation factor of Cu from straw to grain increased by 17.9%-33.6%, respectively, compared with the control treatment. Application of PAA, PAM, and HA significantly decreased the translocation factor of Cd from root to straw by 15.2%-38.5%, compared with the control treatment, but with the exception of HA, had no effect on Cd translocation from straw to grain. In general, the application of soil conditioners promoted rice growth, inhibited the uptake of Cu and Cd by rice, and had a certain remediation effect on heavy metal contaminated soil.