Investigating the effects of municipal waste compost and nitrogen application on the yield and concentration of heavy metals in soil and Spinach (Spinacea oleracea. L)

In order to evaluate the effects of municipal waste and nitrogen fertilizer application on spinach yield and heavy metal concentration in soil and spinach, a field experiment with 9 treatments was conducted in a factorial design. The effect of municipal waste compost, nitrogen and their interaction on yield was statistically significant. The highest yield of spinach at 68600 kg ha-1 was obtained from 20 ton / ha compost with 200 kg ha-1 nitrogen. The increase in the concentration of cadmium, nickel and chromium was higher than the maximum concentration of heavy metals in the spinach shoot, respectively, by 700, 279, 471 and 272%, respectively. On the other hand, application of 10 ton / ha of municipal solid waste compost along with 200 kg / ha nitrogen produced 67300 kg / ha with heavy metals within the product range. The use of municipal waste compost significantly increased the total concentrations of soil lead, nickel, cadmium and chromium, but this increase was not beyond the permissible range. However, limited use of municipal waste compost at 10 ton / ha with 200 kg / ha nitrogen, together with monitoring of soil and plant concentrations of these metals can increase yield of spinach, without heavy metal concentration. Exceeds the standard range in crop and soil.