Study of heavy metal uptake by crop

Abstract

This study evaluates heavy metal uptake by crop, namely Cosmos caudatus, Cymbopogan citratus, Cordyline fruticosa Kiwi and Cordyline fruticosa Red Sister, as these species are often seen in daily lives. Heavy metal used in this study is Zinc and Copper, to artificially contaminate soil before replanting the crop in the study site. Enrichment coefficients of shoots help evaluates the transfer from roots to shoots and potential of crops to be hyperaccumulators. Atomic Absorption Spectrophotometer (AAS) was used to determine the Zinc and Copper concentration in different layers of soil (top, middle and bottom) and in different parts of crops (leaves, stems and roots). Digestion of samples was done using nitric acid digestion method. Watering the plants and uneven mixing of soil with heavy metal affect soil concentrations in different layer. Uptake of Zinc from soil in crop for Cosmos caudatus were observed to be Stem > Leaves > Roots, for Cymbopogan citratus is Root > Stems > Leaves, for both Cordyline fruticosa were observed to be Leaves > Stems > Roots. Uptake of Copper from soil for Cosmos caudatus were observed to be Leaves > Stems > Roots, for Cymbopogan citratus is Root > Leaves > Stems, for Cordyline fruticosa Kiwi, concentrations were Roots > Leaves > Stems at lower concentration but Leaves > Stems > Roots at higher concentration and for Cordyline fruticosa Red Sister it is observed to be Roots > Leaves = Stems.