Investigation of the Effect of Compost Consumption on Residual Amount of Copper and Zinc in Soils and Evaluation of theProcess of Changes in pH and EC

Excess amounts of metals in soil can lead to greater absorption by plants.Adsorption of heavy metals by plants is affected by their concentration in thesoil, their shape, physical and chemical properties of soil, plant nutrition andgrowth stage. The aim of this study was to investigate the effect of organiccompost fertelizer on various forms of zinc and copper in soil and determinethe amount of residual metals in soil and assessment of the process ofchanges in pH and EC in the drained water obtained from the soil columnleaching. In this study, 4 treatments of compost and heavy metals (Zn, Cu)and 2 control treatments , one of them soil with compost and the other onesoil without compost in a completely randomized design was prepared. Afterfilling the soil columns, leaching tests were conducted during 25 days onalternate days. The obtained springlet water in each day was taken to thelaboratory to determine pH and EC values. After leaching, fractionalextraction of samples was conducted for better understanding of heavyelements bonding with different combinations. The results showed thatleaching on pH and EC during twelve leaching was effective. PH and ECvalues on twelve leachings were significant at 1% level. After leaching, testsshowed that only a small amount of copper and zinc in the soil column istransferred to drained water and the bulk of metals remained in phase.

Keywords:

Compost , Copper (Cu) , Zinc ( Zn) , fractionational extraction