Influences of phosphate nutritional level on the phytoavailability and speciation distribution of cadmium and lead in soil  

作　　者：CHEN Su SUN Tie-heng SUN Li-na ZHOU Qi-xing CHAO Lei 

机构地区：[1]Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China [2]Key Laboratory of Environment Engineering of Shenyang University, Shenyang 100041, China [3]Graduate School of Chinese Academy of Sciences, Beijing 100039, China

出　　处：《Journal of Environmental Sciences》2006年第6期1247-1253,共7页环境科学学报（英文版）

基　　金：The National Basic Research Program (973) of China (No. 2004CB418506);the National Natural Science Foundation of China(No. 20477029)

摘　　要：A pot experiment was conducted to examine the influence of phosphate levels on the phytoavailability and speciation distribution of cadmium （Cd）, lead （Pb） in soil. Spring wheat （Triticum aestivum L.） was selected as the tested plant. There were 5 phosphate fertilizer（Ca（H2PO4）2） levels including 0, 50, 100, 200, and 400 mg P2O5/kg soil, marked by P0, P1, P2, P3, and P4, respectively. CdCl2·2.5H2o and Pb（NO3）2 were added to soil as the following levels： Cd ＋ Pb = 25＋0, 0＋1000, and 25＋1000 mg/kg, marked by T1, T2, and T3, respectively. The results showed that the P fertilizer promoted the dry weight of wheat in all treatments and alleviated the contamination induced by Cd and Pb. With increasing levels of the additional P fertilizer, Cd concentration in different parts （root, haulm, chaffand grain） of wheat decreased at the P1 level at first and then increased. The soluble plus exchangeable （SE） fraction of Cd in soil decreased at the P1 level and then increased from P2 to P4 levels. The moderate P fertilizer reduced the phytoavailability of Cd. The application of P could obviously restrain the uptake of Pb by wheat and there were significantly negative correlations between the levels of P and the uptake of Pb. Phosphorus supply resulted in a decrease in the SE fraction of Pb and there was a significantly negative correlation between the levels of P and the SE fraction of Pb in soil. All the levels of the P fertilizer in this experiment could reduce the phytoavailability of Pb. Thus, it is feasible to apply the P fertilizer （Ca（H2PO4）2） to Pb contaminated soils. However, the levels of P application should be restricted in case that redundant P may increase the phytoavailability of Cd.A pot experiment was conducted to examine the influence of phosphate levels on the phytoavailability and speciation distribution of cadmium （Cd）, lead （Pb） in soil. Spring wheat （Triticum aestivum L.） was selected as the tested plant. There were 5 phosphate fertilizer（Ca（H2PO4）2） levels including 0, 50, 100, 200, and 400 mg P2O5/kg soil, marked by P0, P1, P2, P3, and P4, respectively. CdCl2·2.5H2o and Pb（NO3）2 were added to soil as the following levels： Cd ＋ Pb = 25＋0, 0＋1000, and 25＋1000 mg/kg, marked by T1, T2, and T3, respectively. The results showed that the P fertilizer promoted the dry weight of wheat in all treatments and alleviated the contamination induced by Cd and Pb. With increasing levels of the additional P fertilizer, Cd concentration in different parts （root, haulm, chaffand grain） of wheat decreased at the P1 level at first and then increased. The soluble plus exchangeable （SE） fraction of Cd in soil decreased at the P1 level and then increased from P2 to P4 levels. The moderate P fertilizer reduced the phytoavailability of Cd. The application of P could obviously restrain the uptake of Pb by wheat and there were significantly negative correlations between the levels of P and the uptake of Pb. Phosphorus supply resulted in a decrease in the SE fraction of Pb and there was a significantly negative correlation between the levels of P and the SE fraction of Pb in soil. All the levels of the P fertilizer in this experiment could reduce the phytoavailability of Pb. Thus, it is feasible to apply the P fertilizer （Ca（H2PO4）2） to Pb contaminated soils. However, the levels of P application should be restricted in case that redundant P may increase the phytoavailability of Cd.

关 键 词：PHOSPHATE PHYTOAVAILABILITY speciation distribution CADMIUM LEAD 

分 类 号：X131.3[环境科学与工程—环境科学]