Metal Uptake by Barley Seedlings Grown on Soils Amended with Sewage Sludge1
- R. H. Dowdy and
- W. E. Larson2
The removal of metals by 30-day-old barley seedlings (Hordeum vulgare L., cv. Traill) from two topographically associated soils having pH's of 5.9 and 7.9 (free carbonates) was studied following the application of 0, 3.8, 7.6, 15.2, and 30.4 tonne/ha of sewage sludge. One set of soil-sludge samples were incubated for 1-growing-degree year before cropping to study the effect of sludge degradation on metal availability.
Total uptake of Zn, Pb, Ni, and Cr was greater from the sludge-amended acid soil than from the calcareous soil. Incubation resulted in greater removal of Zn, Pb, Ni, and Cr from the acid soil. For the alkaline soil, incubation increased Cr uptake, but had no effect on Zn, Pb, Cu, and Ni uptake. In general, with the exception of Cu, metal uptake was greater from the incubated, acid soil-sludge mixture than from a comparable nonincubated or alkaline mixture.
Sludge applications did not affect the amount of Ca and Mg extracted, but increased Na uptake. Conversely, the Ca and Mg concentration in barley tops decreased as the Na concentration increased with added sludge. The Fe concentration in the leaf tissue of seedlings grown on the acid soil was greatly depressed by the application of 30 tonne/ha of sewage sludge.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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