%0 Journal Article
%T Cadmium and Zinc Concentration in Grain of Durum Wheat in Relation to Phosphorus Fertilization, Crop Sequence and Tillage Management
%A Xiaopeng Gao
%A Cynthia A. Grant
%J Applied and Environmental Soil Science
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/817107
%X Field experiments were conducted at two locations in Manitoba, Canada, to determine the effect of crop rotation, phosphorus (P) fertilization and tillage on grain yield and grain concentrations of Cd and Zn in durum wheat (Triticum durum L.). Compared to conventional tillage (CT), reduced tillage (RT) management decreased grain Cd and increased grain yield and grain Zn in half of the site-years. The type of preceding crops of spring wheat-flax or canola-flax had little influence. Rate and timing of P application had little effect on grain Cd, but increasing P rate tended to decrease grain Zn. No interactive effect was detected among tested factors. Grain Zn was not related to grain Cd, but positively to other nutrients such as Fe, Mn, P, Ca, K, and Mg. Both grain Zn and Fe correlated positively with grain protein content, suggesting protein may represent a sink for micronutrients. The study suggested that the tillage management may have beneficial effects on both grain yield and quality. Phosphorus fertilizer can remain available for subsequent crops and high annual inputs in the crop sequence may decrease crop grain Zn. Understanding the environment is important in determining the impact of agricultural management on agronomic and nutrient traits. 1. Introduction Cadmium (Cd) accumulation in soils and cereal crops and its transfer to the human diet is a widespread problem around the world. Durum wheat (Triticum durum L.) is of particular concern because it accumulates more Cd than the other commonly grown cereals with accumulation increasing in the order of rye < barley < oats < bread wheat < durum wheat [1]. Cadmium concentration in durum wheat grain harvested on Canadian prairies have been reported to range from less than 50 to more than 300£¿¦Ìg kg£¿1 [2], at times exceeding the 200£¿¦Ìg kg£¿1 limit set by the Codex Alimentarius Commission [3]. In addition, approximately 2.1 ¡Á 106£¿ha durum wheat, which occupies 10% of worldwide durum production area, is grown in the western Prairie region of Canada [4]. Therefore, there is a desire in the Canadian farming industry to control the Cd levels in the durum grain, either by improved agricultural management practices [5] or by breeding low Cd-accumulating cultivars [6, 7]. Accumulation of metal elements in crop grains can be regulated by several physiological processes, including uptake from the soil solution, root-to-shoot translocation, and retranslocation into the grain during maturation. Zinc (Zn) and Cd are chemically similar and can compete for common transport mechanisms for uptake and translocation in
%U http://www.hindawi.com/journals/aess/2012/817107/