Effect of municipal waste solid compost, cow and Poultry manure on available heavy metal in three different soil texture

Organic matter is one of the most important factors in soil fertility. Different sources are involved in the supply of organic matter, including municipal solid waste compost, poultry and cow manure. These fertilizers often contain toxic substances and heavy metals which are extremely harmful for human and animal health. Toxicity and hazard of heavy metals in the soil is dependent on the form and amount of heavy metal. This research was conducted in a based on design completely randomized with three replications in Hamedan province. In this study, three types of soil texture (sandy loam, clay and loam) along with three types of organic fertilizers such as municipal solid waste compost, poultry and cow manure have been used in 5 levels (0, 20, 40, 80 and 120 Ton/ha). Availability and total concentrations of Zn, Cu, Ni, Pb and Mn were measured in each treatment. The results showed that soil cation exchange capacity (CEC) as well as availability and total amount of heavy metals were increased by enhancing the amount of organic fertilizers. The availability of heavy metals was much less than the total amount of elements. Overall, it was observed that increment of heavy metals caused by organic fertilizers was more in the clay soil compared to other soils because of the fact that clay texture showed high capacity for the uptake of heavy metals. Solid waste compost revealed the greatest effect on increasing the concentrations of heavy metals in the soil among other fertilizers while poultry manure was in the second place.