The Effects of Sewage Sludge and Nitrogen Fertilizer Application on Nutrient and Heavy Metal Concentration of Soil and Smooth Bromegrass (Bromus Inermis Leyss.)

Abstract

In order to evaluate the growth of smooth bromegrass, nutrient and heavy metal accumulation of plant tissue and heavy metal accumulation in soil, this research was conducted. The study included seven treatment: a zero-N (control), three inorganic nitrogen fertilizer rates (50, 100 and 150 kg ha-1) and three sewage sludge rates (7.0, 14.0 and 21.0 Mg ha-1). Sewage sludge and N fertilizer increased dry matter yield and N, K, Cu, Zn, Pb, Cr, Cd contents of smooth bromegrass. The highest dry matter yield obtained at the highest sewage sludge (21.0 Mg ha-1) and the highest N fertilizer (150 kg N ha-1). Applications did not effect P, Cu, Mg, Cr (only 2005 year), Fe and Mn contents of plant tissue. At the end of research (2006 year), soil samples for Fe, Mn, Zn, Cu, Pb and Cd analysis were collected in three soil depth (0-20, 20-40 and 40-60 cm) for all application. N fertilizer and sewage sludge application had no effect in 20-40 and 40-60 cm soil depth for all analysed elements. Applications had very effect in only 0-20 cm soil depth (on surface soil). Compared to control plots, sewage sludge increased DTPA-extractable Fe, Mn, Zn, Cu, Pb and Cd contents of soil. © Medwell Journals, 2010.