Effects of phosphorus and zinc fertilizer on cadmium uptake and distribution in flax and durum wheat

Abstract

Cadmium accumulation in crops presents a potential risk to human health. To understand the difference between dicotyledonous and monocotyledonous species in respect of Cd accumulation, and to develop fertilizer management practices to minimise Cd uptake, a growth chamber study was conducted to evaluate the interactive effects of Cd concentration in phosphate and Zn fertilizer on Cd uptake in flax (Linum usitatissimum L) and durum wheat (Triticum turgidum L). Cadmium concentration was higher in flax than durum wheat shoots. Cadmium concentration was lower and Zn concentration higher in the flax seed and durum wheat grain than in the root, shoot or straw of both species. These results suggest that flax has comparatively ineffective barriers discriminating against the transport of Cd from the root to the shoot via the xylem, and that both crops may restrict Cd translocation to the seed/grain via the phloem. Commercial grade monoammonium phosphate (NH 4 H 2 PO 4 ) or triple superphosphate (Ca(H 2 PO 4 ) 2 ) produced higher seed Cd concentrations than did reagent grade P in flax but not in durum wheat. Application of P significantly decreased seed/grain Zn concentration and increased seed/grain Cd concentration. Zinc addition at 20 mg Zn kg −1 soil with P decreased seed/grain Cd concentration (average 42.2% for flax, 65.4% for durum wheat), Cd accumulation (average 37.2% for flax, 62.4% for durum wheat) and Cd translocation to the seed/grain (average 20.0% for flax, 34.5% for durum wheat) in both crops. These results indicate that there is an antagonistic effect of Zn on Cd for root uptake and distribution within the plant.

Cadmium and Zinc Concentration in Grain of Durum Wheat in Relation to Phosphorus Fertilization, Crop Sequence and Tillage Management

“…In a short-term growth chamber study [18], the immediate increase of Cd accumulation in durum wheat following phosphate application was mostly due to increased Cd uptake and translocation by decreasing Zn accumulation in durum wheat induced by P fertilization, rather than to a direct addition effect. Similar results were also reported in other studies [19,20], where using reagentgrade phosphate increased Cd concentration, but decreased Zn concentration of durum wheat. Though these studies showed the long-term or short-term effect of P fertilization on phytoavailability of Cd and Zn in soil-plant system, there is little information available on the effect of the residual P from P fertilizer that was applied to preceding crops.…”

Association of trace metals with various sedimentary phases in dam reservoirs

“…The dumps of the past mining operations leach significant amounts of zinc and cadmium. It is also used for galvanization process (Jiao et al, 2004).…”

“…The dumps of the past mining operations leach significant amounts of zinc and cadmium. It is also used for galvanization process (Jiao et al, 2004). The hydrolysis of Pb 2+ , under progressively increasing alkaline conditions, forms Pb(OH) + , Pb(OH) 2 (aqueous), Pb(OH) 3 -and other species, including several polynuclear species (Broadley et al, 2007).…”

Influence of soil type and natural Zn chelates on flax response, tensile properties and soil Zn availability

“…This susceptibility is heightened by P application (Burleson and Page 1967;Jiao et al 2007;Loneragan et al 1979;Millikan et al 1968;Moraghan 1984;Spratt and Smid 1978) and also influenced by the presence of Fe, which determines normal chlorophyll formation and the development of green plant tissue (Lee et al 1969). Field studies have been conducted to evaluate the interactive effects of phosphate and ZnSC>4 fertilizers on different soil types and Cd uptake and their distribution in flax (Grant and Bailey 1997;Jiao et al 2004). Various abnormalities, which are apparently nutritional in origin, often retard growth early in the growing season (Flor 1943;Fieldes and Gerhardt 1994).…”