Municipal Sewage Sludge Compost-Amended Soils: Some Spatiotemporal Treatment Effects1
- R. G. Darmody,
- J. E. Foss,
- M. Mc Intosh and
- D. C. Wolf2
Amending soils with composted sewage sludge can be a useful way to both dispose of sewage sludge and improve the chemical and physical properties of soils. Composted, municipal sewage sludge was added to a Chester silt loam (fine-loamy, mixed, mesic Typic Hapludult) in a tree nursery at rates of 0,150, and 300 dry t/ha. Soils were sampled to a depth of 150 cm, in 25-cm increments each year for the 3 y after compost addition, and analyzed for pH and extractable Ca, Mg, K, P, Cu, and Zn. Surface soil pH values and levels of Ca, K, P, Cu, Zn, and organic C increased, while bulk density values decreased with increased compost application. Surface soil levels of extractable K and P increased over 3 y after addition, while the other elements remained stable. Soil Mg content was not significantly changed by compost additions.
With the exception of K, the extractable elements added by compost were found to be mobile. In the 300 t/ha plots, Ca was significantly increased to a depth of 50 cm and pH, P, Cu, and Zn was significantly increased to 75 cm. Depth of significant increase was less in the 150 t/ha plots. All the elements that increased at depth, except Cu, showed a gradual decline in concentration from the surface. In the 300 t/ha plots, Cu concentration gave a maximum in the B horizon.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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