Municipal sewage sludge compost-amended soils: Some spatiotemporal treatment effects

Composted, municipal sewage sludge was added to a Chester silt loam 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.