Low-Cost Agricultural Measures to Reduce Heavy Metals Uptake by Food Crops

Heavy metal contamination afects large areas of Iran and worldwide. Hot spots of pollution are located close to industrial sites, around large cities and in the vicinity of mining and smelting plants. Agriculture in these areas faces major problems due to heavy metal transfer into crops and subsequently into the food chain. This paper gives an overview on simple but efective countermeasures to reduce the uptake of heavy metals by food crops. Since crop species and varieties largely difer in their heavy metal uptake, choosing plants with low transfer factors (e.g., legumes, cereals) may reduce metal concentration in edible parts signifcantly. The application of soil amendments is another very efective measure to reduce the concentration of heavy metals in crops. Both organic (e.g., farmyard manure) and inorganic amendments (e.g., lime, zeolites, and iron oxides) were found to decrease the metal accumulation. Further efective methods to reduce metal transfer into food chain include crop rotation and cultivation of industrial or bio-energy crops. It is concluded that the methods presented here comprise several tools, which are easy to apply, and are efective to allow safe agriculture on moderately contaminated soils.