Effects of municipal sewage sludge doses on the yield, some yield components and heavy metal concentration of dry bean (Phaseolus vulgaris L.)

Abstract

Significant grain yield increase to applied municipal sewage sludge was obtained. This study was carried out in order to investigate the effects of the different doses municipal sewage sludge application on the heavy metal concentrations, yield and quality of dry bean in the 2006 and 2007 years. The trial was conducted in randomized complete block design with three replications. Four municipal sewage sludge doses (0, 20 000, 40 000 and 60 000 kg ha-1) were applied. Significantly higher pod and seed number per plant in municipal sewage sludge treatments had increasing effects on grain yield. Whereas grain yield, which was the highest component was obtained from 60 000 kg ha-1 municipal sewage sludge with 1766.3 kg ha-1 in the first year and with 1881.6 kg ha-1 in the second year. The lowest grain yield were obtained from 0 kg ha-1 municipal sewage sludge in both years. 60 000 kg ha-1 municipal sewage sludge application was optimal with respect to increasing yield and yield characteristics. Concentrations of heavy metals in grain and shoot were similar to those in the fertilizer treatments. Cu, Zn, Cr, Pb and Ni in grain and shoot were well below their toxic thresholds