Effect of Biosolids on Phytoavailability of Cd in Long-Term Amended Soils. (S11-kukier764272-oral)
Authors:
U. Kukier* - Virginia Tech
R.L. Chaney - USDA-ARS, Beltsville, MD J.A. Ryan - US-EPA, Cincinnati, OH W.L. Daniels - Virginia Tech
R.H. Dowdy - USDA-ARS, St. Paul, MN
T. Granato - Water Reclamation District Greater Chicago, Cicero
Abstract:
Soils for a greenhouse study were collected from paired long-term biosolids-amended and unamended (control) field plots at Beltsville, MD, St. Paul, MN and Fulton Co., IL. Biosolids application was terminated at these plots 24, 20, and 16 years before sampling, respectively. The soils were amended with increasing rates of Cd-salt (from 0 to 10 mg kg-1), which was enriched in 111Cd. The soils were adjusted to equal pH of 6.5 (measured in 0.01 M calcium nitrate) and cropped with Romaine lettuce to evaluate long-term phytoavailability of Cd applied with biosolids, and freshly applied Cd.
Biosolids-applied Cd was about 100% labile in all soils except for Fulton Co. plots. Plant uptake of freshly added Cd was greatly reduced in the biosolids-amended compared to control soils, indicating that biosolids decreased Cd phytoavailability in a persistent manner. For example, lettuce grown in control Beltsville soil amended with 10 mg kg-1 Cd-salt accumulated 72 mg Cd kg-1 DW, but only 11-49 mg Cd kg-1 DW when grown in soil amended with various biosolids and 10 mg kg-1 Cd-salt.
This persistent Cd sorption process in biosolids-amended soils reduces the potential for food-chain transfer of biosolids-Cd. Results will be evaluated in relation to soil and biosolids properties.
Speaker Information: Urszulaq Kukier, Virginia Tech, USDA-ARS-AMBL Bldg. 007, Room 015 BARC-West, Beltsville, MD 20705-2350; Phone: 301-504-5399; E-mail: [email protected]
Session Information: Tuesday, November 4, 2003, 8:10 AM-11:00 AM Presentation Start: 8:10 AM
Keywords: cadmium; biosolids; phytoavailability; stable-isotope
