Soil Temperature Effects on Uptake of Cadmium and Zinc by Vegetables Grown on Sludge-amended Soil1
- P. M. Giordano,
- D. A. Mays and
- A. D. Behel2
The effects of soil temperature on the uptake of heavy metals by plants grown on sludge-amended soil has not been established. A field experiment was initiated in 1975 to determine uptake of Cd and Zn by several vegetables from Sango sil amended with 224 metric tons/ha of an anaerobically digested sewage sludge. A variety of commonly grown garden vegetables was selected since many home gardeners have been utilizing digested sewage for its nutrient and soil conditioning value. Soils were heated to approximately 27°C using thermostatically controlled resistance cables placed 30 cm deep and 30 cm apart in the soil. Crops were grown in 1975, 1976, and 1977 to measure Immediate and residual uptake of heavy metals in edible plant parts.
Concentrations of DTPA-extractable metals in soil increased from 1975 to 1977, but these increases were not reflected in higher plant concentrations. Soil heating significantly increased Cd and Zn concentrations in broccoli and potato; concentrations of Cd and Zn were higher in several other vegetables with heating but differences were not statistically significant. Liming reduced the concentration of Zn and Cd in the crops, but dilution due to better growth may have accounted for a part of the reduction. Analyses of soil cores taken after cropping in 1977 indicated movement of Zn and Cd to a maximum depth of 20 to 30 cm.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .