Changes in Soil Physical Properties and Concentrations of Lead and Chromium in Spinach Affected by Enriched Municipal Compost

In order to investigate the effects of municipal solid waste enriched with mineral fertilizers on some soil physical properties and lead (Pb) and chromium (Cr) concentration in plant organs of spinach، a field experiment was carried out in a factorial arrangement based on the randomized complete block design with three replications in 2008. The main plot included four levels of fertilizer، control without fertilizer، 20 tons of multiple solid waste + 50% chemical fertilizers and 40 tons of multiple solid waste + 50% chemical fertilizers per hectare and sub-plot consisted of a period of application in 3 levels of time (one، two and three years). The results showed that application of enriched municipal compost increased field capacity، soil porosity and moisture holding capacity، but particle and bulk density of soil decreased compared to the control. Also، the physical parameters in the two levels of emriched waste compost were higher than chemical fertilizer treatment. On the other hand، using for three-years the urban waste compost enriched fertilizer at all levels increased significantly (p 0. 05) lead and chromium concentrations in spinach. The Pb and Cr accumulated in roots and shoots of spinach in urban using 40 tons of waste compost per hectare with 50 percent of chemical fertilizer for a period of three years and showed a significant increase. The amounts of fertilizer in all three levels were higher than the root element shoot.