Influence of cereal varieties and site conditions on heavy metal accumulations in cereal crops on polluted soils of Bangladesh

The present work describes results of pot experiments and field studies including three contaminated sites in Bangladesh. The aim was to investigate possible differences between cereal varieties with regard to heavy metal uptake and accumulation. A total of 10 rice (Oriza sativa L.) and 3 wheat (Triticum aestivum) varieties were studied. Soil samples were digested with HCl:HNO3 (3:1), and plant samples were digested with a HNO3:HClO4 (5:1) mixture in closed systems. All elements with exception of cadmium (Cd) and mercury (Hg) were measured in the extracts by plasma emission spectroscopy (ICP-AES). Cadmium was measured by atomic absorption spectroscopy (AAS), with a heated graphite-tube system (HGA). Mercury was measured by AAS, using mercury-hydride system (MHS-20). The rice variety BR-14 exhibited the highest yield and in most cases the lowest heavy metal accumulations at harvest. Wheat varieties showed significantly different heavy metal accumulation. It can be concluded that selection of cereal varieties may add to safer crop production on heavy metal contaminated sites. Nevertheless, site specificity of this measure has to be taken into account.