Influence of municipal solid waste compost application on heavy metal content in soil

Municipal solid waste composts (MSWC) are widely used over agricultural lands as organic soil amendment and fertilizer. However, MSWC use may result in various adverse impacts over agricultural lands. Especially, heavy metal contents of MSWC should always be taken into consideration while using in agricultural practices. The present study was conducted to find out heavy metal contents of municipal solid waste compost (MSWC) and to investigate their effects on soils. Experiments were carried out in three replications as field experiments for 2 years. Dry-based MSWC was applied to each plot at the ratios of 0, 40, 80, 120, 160, 200 t ha−1. Results revealed that heavy metal content of MSWC was within the allowable legal limits. Compost treatments significantly increased Cu, Zn, Ni, Cr, Cd, and Pb content of soils (p <0.01). Increasing soil heavy metal contents were observed with increasing applied compost doses. Although compost treatments significantly increased soil heavy metal contents, the final contents were still within the allowable legal limits. Results showed that MSWC doses over 10 t ha−1 may create a heavy metal risk in long term for soils with pH ≥ 7. Therefore, in MSWC use over agricultural lands, heavy metal contents should always be taken into consideration and excessive uses should be avoided.