Abstract:
Due to the fact that possible risk associated with soil-crop-food chain transfer, metal contamination in
croplands has become a major topic of wide concern. Accumulation of toxic metals in edible parts of crops
grown in contaminated soils has been reported from number of crops including rice, soybean, wheat, maize,
and vegetables. Therefore, in order to ensure food safety, measures are needed to be taken in mitigating metal
pollution and subsequent uptake by crop plants. Present paper critically reviewed some of the cost effective
remediation techniques used in minimizing metal uptake by crops grown in contaminated soils. Liming with
different materials such as limestone (CaCO3), burnt lime (CaO), slaked lime [Ca(OH)2], dolomite
[CaMg(CO3)2], and slag (CaSiO3) has been widely used because they could elevate soil pH rendering metals
less-bioavailable for plant uptake. Zn fertilization, use of organic amendments, crop rotation and water
management are among the other techniques successfully employed in reducing metal uptake by crop plants.
However, irrespectively the mitigating measure used, heterogeneous accumulation of metals in different crop
species is often reported. The inconsistency might be attributed to the genetic makeup of the crops for selective
uptake, their morphological characteristics, position of edible parts on the plants in respect of their distance
from roots, crop management practices, the season and to the soil characteristics. However, a sound
conclusion in this regard can only be made when more scientific evidence is available on case-specific
researches, in particular from long-term field trials which included risks and benefits analysis also for various
remediation practices.
