Cd Uptake by Maize Increases Greatly When Intercropped with Legumes

Recently, Prof. LI Zhian and his research team, soil science and ecological engineering research group of South China Botanical Garden (SCBG) found that Cd uptake by Maize from soil greatly increased when it was intercropped with legumes. Cicer arietinum worked best in promoting Cd uptake by maize, causing the highest Cd accumulation in maize within a relatively short time. Since C. arietinum resulted in a relatively large maize bioconcentration factor of 2.0 and large transfer factor of 0.55, it seemed to be the most valuable intercrop for enhancement of Cd removal from soil by maize. Their study also found that Amaranthus hypochondriacus is a hyperaccumulator of Cd and is promising in phytoremediation of Cd contaminated soil. This species has very large biomass potential and high tissue concentration of Cd. The results suggest that, for optimum phytoremediation, it may not be necessary to harvest either the main crop or intercrops at a mature stage of growth. 

Environmental pollution and food safety have become global concerns during the past several decades. Heavy metal contaminated land is steadily increasing around the world, especially in developing countries. An alternative strategy involves the use of high biomass plants (e.g. Maize) that are usually not metal-specific and contain low to moderate heavy metal concentrations. Therefore it is now a hotspot how to enhance the ability of these plants to uptake heavy metals.

The above discovery was published recently in the internationally prestigious journal, Water, Air and Soil Pollution.