Cadmium accumulation in crops

Abstract

Cadmium is a heavy metal present in soils from natural and anthropogenic sources. Plant uptake of Cd at levels present in the soil solution is dependent on a system that is largely metabolically mediated and competitive with the uptake system for Zn and possibly other metals. Much of the Cd taken up by plants is retained in the root, but a portion is translocated to the aerial portions of the plant and into the seed. The amount of Cd accumulated and translocated in plants varies with species and with cultivars within species. Soil, environmental and management factors impact on the amount of Cd accumulated in plants. Potential methods of reducing the accumulation of Cd in crops include reduction of Cd input to the soil system, site selection, management practices which decrease the concentration of Cd in the soil solution and its uptake and translocation by plants, and development and production of plant cultivars with the genetic tendency for low Cd uptake.

Intraspecific differences in effects of co-contamination of cadmium and arsenate on early seedling growth and metal uptake by wheat

“…The great differences in Cd and As tolerance have been found among varieties within a species (Grant et al, 1998;Jalil et al, 1994). Wheat, the main food in North China, is an important crop in China and its cultivating covers about 22% of the total arable lands.…”

Effects of source and placement of phosphorus on concentration of cadmium in the grain of two durum wheat cultivars

“…The amount of Cd in the soil, metal sorption capacity, and pH of the soil are some of the most important factors affecting Cd concentration in solution (Bramley 1990). Of these factors, pH is probably dominant (Grant et al 1998) as it affects solubility of Cd compounds, metal sorption capacity of the soil (Bramley 1990), and Cd speciation (Naidu et al 1994). Other factors such a soil texture and organic matter content have an influence on Cd availability to plants because they affect sorption of the metal to soil surfaces.…”

“…Other factors such a soil texture and organic matter content have an influence on Cd availability to plants because they affect sorption of the metal to soil surfaces. In general Cd uptake and accumulation in plants decreases in soils with finer texture (Grant et al 1998), and in soils with higher organic matter content (Jastrow and Koeppe 1980). Given the nature of the factors affecting Cd uptake by plants, management factors, such as fertilization, that influence the rate of plant growth and root system development, evapotranspiration, and ionic strength of the soil solution can have a strong influence on Cd uptake (Villarroel et al 1993;Naidu et al 1994;Grant et al 1998).…”

“…In general Cd uptake and accumulation in plants decreases in soils with finer texture (Grant et al 1998), and in soils with higher organic matter content (Jastrow and Koeppe 1980). Given the nature of the factors affecting Cd uptake by plants, management factors, such as fertilization, that influence the rate of plant growth and root system development, evapotranspiration, and ionic strength of the soil solution can have a strong influence on Cd uptake (Villarroel et al 1993;Naidu et al 1994;Grant et al 1998). Of special concern is the use of phosphatic fertilizers because they contain varying amounts of Cd as a contaminant, reflecting the Cd content of the rock from which the fertilizer was derived (Williams and David 1973).…”

“…To address the concerns about Cd toxicity, the World Health Organization has set a provisional weekly tolerable intake of 7 µg per kg of liveweight (World Health Organization 1996), and the Codex Alimentarius Commission of FAO/WHO has proposed a Cd concentration limit of 100 µg kg -1 for cereal grains and oilseeds traded in international markets (Grant et al 1998).…”