Bioaccumulation and Translocation of Heavy Metals in Paddy (Oryza sativa L.) and Soil in Different Land Use Practices

Abstract

Rice tends to accumulate heavy metals present in soil that have been introduced by human activities and pass them up the food chain. The present study aimed to evaluate the accumulation of selected trace elements (Cu, Zn, and Pb) in paddy and soil and the transfer of these metals from soil to rice by analysing the bioconcentration factor (BCF), bioaccumulation factor (BAF), and translocation factor (TF) of heavy metals in paddy (Oryza sativa L.) and soil. Samples of matured paddy and the substrates were collected from three different areas located near a rural point (RP), a transportation point (TP), and an industrial point (IP). Heavy metal concentrations present in the soil and various parts of the plants were ascertained using an atomic absorption spectrophotometer (AAS). Cu, Zn, and Pb accumulation in the soil were detected in increasing orders of RP > TP > IP, IP > TP > RP, and IP > RP > TP, respectively. The BCFshoot, BAF, and transfer factor of both Zn and Pb from soil to rice were detected in the order of TP > IP > RP, which was different from Cu, where BCFshoot and TF showed the order of RP > IP > TP but the BAF indicated IP > RP > TP. TF > 1 was discovered for Zn and Pb at the TP, and for Cu at the RP, which could be attributed to the TP’s strongly acidic soil and Cu’s abundance in the RP’s soil. Paddy height and yield traits were the most significant at the IP site, showing the highest number of fertile spikelets, the average weight of a 1000-paddy spikelet, and the harvest index (0.56). These findings can be related to the normal range of Zn and Pb found in rice plants that support growth. Thus, the findings of this study demonstrated that soil properties and metal abundance in soil from certain land use practices can partially influence the mobility and transfer of metals through soil–plant pathways.