CADMIUMAVAILABILITY AND UPTAKE BY RAPE (BRASSIA CAMPESTRIS L.) GROWNIN CONTAMINATED SOILS APPLIED WITH ORGANIC AMENDMENTS

摘要

Soil cadmium(Cd) pollution has become a se-rious environmental focus of attention of the worldwide. Cd availability in soils and uptake by rape (Brassia campestris L.) grown in Cd-contaminated soils after supplied the mixture of wheat or corn straw and chicken manure as organic amendments(labeled as WC and CC)into soils were studied. Results showed that WC amendments application generally promoted the dry matter of rape tissues at the first 50 days and significantly improved antioxidant enzymes activity of rape leaves regardless of planting period. Application with WC amendment might be more advantageous in decreasing Cd uptake by rape than CC amend-ment. It was worth mentioning that Cd contents in roots, stems and leaves reduced by 50.84% and 63.14% at the second 50 days when supplied WC amendment of 12.0g kg'of TOC into soils. Appli-cation with WC amendment could effectively de-cline the Cd availability on account of the Cd form redistribution from exchangeable Cd to unavailable Cd. Additionally, significantly negative correlations (P<0.01)between the soil pH, SOM content and exchangeable Cd were observed. After supplied with WC amendment into soil, the increases of soil pH and SOM content were also contributed to the reduction of Cd availability in soils and rape uptake. Accordingly, the mixture of wheat straw and chicken manure can be used as an organic amend-ment to reduce soil Cd availability and plant uptake in heavy metal contaminated soils.