Effect of Composted Municipal Sewage Sludge on Growth and Elemental Composition on White Pine and Hybrid Poplar

Abstract

AbstractA field study was conducted to determine the benefits of land application of composted municipal sewage sludge to white pine (Pinus strobus L.) and hybrid poplar (Populus deltoides spp., P. angulata × P. trichocarpa) growth. Composted municipal sewage sludge was disked into a Chester silt loam (Typic Hapludult—fine loamy, mixed, mesic) at rates of 0, 150, and 300 dry Mg/ha. White pine seedlings and hybrid poplar cuttings were grown for 3 y on the plots which had been seeded with ‘Kentucky 31’ tall fescue (Festuca arundinacea Schreb.).White pine growth was not affected by the compost treatments. Poplar growth, however, increased as a result of the compost application. After 3 y, the average hybrid poplar heights were 233, 443, and 483 cm for the 0, 150, and 300 Mg/ha treatments, respectively. The height differences between the control and the compost‐amended plots were due to a faster growth rate and a longer growth period of the trees on the compost‐amended plots. Hybrid poplars grown on the compost‐amended soil had higher concentrations of N and K and a lower concentration of Zn in the leaves than the control. No consistent differences in elemental composition of the white pine needles were apparent.