Effect of Three Types of Organic Fertilizers on the Heavy Metals Transfer Factor and Maize Biomass

Organic matter plays an important role in the soil fertility as well as physical and biological properties of soil. However, these organic fertilizers sometimes contain heavy metals which are very harmful to human health. So, the aim of this study was to investigate the effect of three types of organic fertilizers on the heavy metals transfer factor (TF) and maize biomass. For this purpose, pot experiment in a completely randomized factorial design was used with three replications and three types of soil as well as three types of organic fertilizers such as municipal solid waste compost, poultry manure and cow manure have been used at 5 levels in Hamedan province, Iran. Heavy metals TF, biomass and amount of heavy metals in maize root were measured. In this research, sandy loam has received all three types of fertilizer while only compost was added to the clay and loam soil. Results demonstrated that TF value for Pb was higher than one in all three soil textures indicating the high concentration of Pb in the maize shoots. The TF value of Zn was increased from 0.33 to 0.66 mg/kg by enhancing the amount of municipal solid waste compost. The TF of Pb in the shoots showed greater value in the municipal solid waste compost with amount of 1.35 mg/kg compared to the poultry manure and cow manure with amount of 0.33 and 0.94 mg/kg, respectively and 120 Ton/ha compost treatment accounted for the highest value of TF for Pb. Furthermore, the maximum biomass of maize was related to the sandy loam with amount of 120 Ton/ha compost. In conclusion, the application of organic fertilizers not only is useful for the maize but also contributes to increase in the biomass of this plant.