University of Tabriz Water and Soil Science 2008-5133 28 3 2018 09 23 Effect of Apple Pruning Residue Biochar on Chemical Forms, Mobility Factor Index (MF) and Reduced Partition Index (IR) of Heavy Metals in a Contaminated Soil Effect of Apple Pruning Residue Biochar on Chemical Forms, Mobility Factor Index (MF) and Reduced Partition Index (IR) of Heavy Metals in a Contaminated Soil 65 78 8127 FA R Hamzenejad Ph.D. Student, Dept. of Soil Science, Urmia University, Iran E Sepehr Assoc. Prof., Dept. of Soil Science, Urmia University, Iran A Samadi Prof., Dept. of Soil Science, Urmia University, Iran MH Rasouli-Sadaghiani Prof., Dept. of Soil Science, Urmia University, Iran H Khodaverdiloo Assoc. Prof., Dept. of Soil Science, Urmia University, Iran Journal Article 2018 11 19 In order to study the effect of apple (Golden delicious variety) pruning residue biochar on chemical forms of Cd, Pb, Cu and Zn in a contaminated soil, an experiment was conducted as a factorial in a completely randomized design (CRD) in three replications with 4 levels of biochar (0, 2, 5 and 10 %) and 4 levels of incubation time (1, 2, 4 and 8 weeks).  Chemical distribution of metals in soil was determined using Tessier sequential extraction method during the mentioned incubation times and the reduced partition index (<em>I_R</em>) and mobility factor (<em>MF</em>) of the metals were calculated. Application of the biochar significantly (<em>p </em>≤ 0.05) decreased the exchangeable and carbonate fractions and increased organic and iron and manganese oxide bound fractions in comparison to the control treatment. With increasing the biochar level and incubation time, the <em>I_R</em> values were increased, but <em>MF</em> values decreased, demonstrating a decrease in the mobility of metal in soils. It was concluded that the addition of the apple biochar in soil may led to transformation of the metals from unstable forms (e.g. exchangeable and carbonate forms) to stable forms (e.g. iron and manganese oxide bound and residual forms), and consequently decreased the mobility of the metals in soil. In order to study the effect of apple (Golden delicious variety) pruning residue biochar on chemical forms of Cd, Pb, Cu and Zn in a contaminated soil, an experiment was conducted as a factorial in a completely randomized design (CRD) in three replications with 4 levels of biochar (0, 2, 5 and 10 %) and 4 levels of incubation time (1, 2, 4 and 8 weeks).  Chemical distribution of metals in soil was determined using Tessier sequential extraction method during the mentioned incubation times and the reduced partition index (<em>I_R</em>) and mobility factor (<em>MF</em>) of the metals were calculated. Application of the biochar significantly (<em>p </em>≤ 0.05) decreased the exchangeable and carbonate fractions and increased organic and iron and manganese oxide bound fractions in comparison to the control treatment. With increasing the biochar level and incubation time, the <em>I_R</em> values were increased, but <em>MF</em> values decreased, demonstrating a decrease in the mobility of metal in soils. It was concluded that the addition of the apple biochar in soil may led to transformation of the metals from unstable forms (e.g. exchangeable and carbonate forms) to stable forms (e.g. iron and manganese oxide bound and residual forms), and consequently decreased the mobility of the metals in soil. https://water-soil.tabrizu.ac.ir/article_8127_b6c61ccefc8559b4f7e0b35ab6197f6b.pdf