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？μg kg？1 [2], at times exceeding the 200？μg kg？1 limit set by the Codex Alimentarius Commission [3]. In addition, approximately 2.1 × 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
References
[1]
Jansson G., Cadmium in arable crops: the influence of soil factors and liming, Ph.D. thesis, Department of Soil Sciences, The Swedish University of Agricultural Sciences, Uppsala Sweden, 2002.
[2]
C. A. Grant and L. D. Bailey, “Nitrogen, phosphorus and zinc management effects on grain yield and cadmium concentration in two cultivars of durum wheat,” Canadian Journal of Plant Science, vol. 78, no. 1, pp. 63–70, 1998.
[3]
“Codex general standard for contaminants and toxins in foods,” CODEX STAN 193-1995, Rev. 5, 2009.
[4]
Canada Statistics, “Crops and horticulture,” 2010, http://www40.statcan.gc.ca/l01/ind01/l3_920_2024-eng.htm?hili_none.
[5]
C. A. Grant, W. T. Buckley, L. D. Bailey, and F. Selles, “Cadmium accumulation in crops,” Canadian Journal of Plant Science, vol. 78, no. 1, pp. 1–17, 1998.
[6]
J. M. Clarke, D. Leisle, R. A. DePauw, and L. L. Thiessen, “Registration of five pairs of durum wheat genetic stocks near-isogenic for cadmium concentration,” Crop Science, vol. 37, no. 1, p. 297, 1997.
[7]
M. J. McLaughlin, D. R. Parker, and J. M. Clarke, “Metals and micronutrients: food safety issues,” Field Crops Research, vol. 60, no. 1-2, pp. 143–163, 1999.
[8]
I. Cakmak, W. H. Pfeiffer, and B. McClafferty, “Biofortification of durum wheat with zinc and iron,” Cereal Chemistry, vol. 87, no. 1, pp. 10–20, 2010.
[9]
E. J. Gawalko, R. G. Garrett, and T. W. Nowicki, “Cadmium, copper, iron, manganese, selenium, and zinc in Canadian spring wheat,” Communications in Soil Science and Plant Analysis, vol. 33, no. 15-18, pp. 3121–3133, 2002.
[10]
C. A. Grant and S. C. Sheppard, “Fertilizer impacts on cadmium availability in agricultural soils and crops,” Human and Ecological Risk Assessment, vol. 14, no. 2, pp. 210–228, 2008.
[11]
K. C. Jones and A. E. Johnston, “Cadmium in cereal grain and herbage from long-term experimental plots at Rothamsted, UK,” Environmental Pollution, vol. 57, no. 3, pp. 199–216, 1989.
[12]
M. A. Kashem and B. R. Singh, “The effect of fertilizer additions on the solubility and plant-availability of Cd, Ni and Zn in soil,” Nutrient Cycling in Agroecosystems, vol. 62, no. 3, pp. 287–296, 2002.
[13]
C. A. Grant and L. D. Bailey, “Effects of phosphorus and zinc fertiliser management on cadmium accumulation in flaxseed,” Journal of the Science of Food and Agriculture, vol. 73, no. 3, pp. 307–314, 1997.
[14]
J. O. Agbenin, “Phosphate-induced zinc retention in a tropical semi-arid soil,” European Journal of Soil Science, vol. 49, no. 4, pp. 693–700, 1998.
[15]
T. S. Verma and R. S. Minhas, “Zinc and phosphorus interaction in a wheat-maize cropping system,” Fertilizer Research, vol. 13, no. 1, pp. 77–86, 1987.
[16]
M. Haldar and L. N. Mandal, “Effect of phosphorus and zinc on the growth and phosphorus, zinc, copper, iron and manganese nutrition of rice,” Plant and Soil, vol. 59, no. 3, pp. 415–425, 1981.
[17]
S. R. Olsen, “Micronutrient interaction,” in Micronutrients in Agriculture, J. J. Mortvedt, P. M. Giordano, and W. L. Lindsay, Eds., pp. 243–264, Soil Science Society of America, Wis, USA, 1972.
[18]
X. Gao, D. N. Flaten, M. Tenuta, M. G. Grimmett, E. J. Gawalko, and C. A. Grant, “Soil solution dynamics and plant uptake of cadmium and zinc by durum wheat following phosphate fertilization,” Plant and Soil, vol. 338, no. 1, pp. 423–434, 2011.
[19]
M. Choudhary, L. D. Bailey, and C. A. Grant, “Effect of zinc on cadmium concentration in the tissue of durum wheat,” Canadian Journal of Plant Science, vol. 74, no. 3, pp. 549–552, 1994.
[20]
Y. Jiao, C. A. Grant, and L. D. Bailey, “Effects of phosphorus and zinc fertilizer on cadmium uptake and distribution in flax and durum wheat,” Journal of the Science of Food and Agriculture, vol. 84, no. 8, pp. 777–785, 2004.
[21]
P. R. Miller, Y. Gan, B. G. McConkey, and C. L. McDonald, “Pulse crops for the northern Great Plains: I. Grain productivity and residual effects on soil water and nitrogen,” Agronomy Journal, vol. 95, no. 4, pp. 972–979, 2003.
[22]
C. A. Campbell, R. P. Zentner, F. Selles et al., “Quantifying short-term effects of crop rotations on soil organic carbon in southwestern Saskatchewan,” Canadian Journal of Soil Science, vol. 80, no. 1, pp. 193–202, 2000.
[23]
C. Hamel, K. Hanson, F. Selles et al., “Seasonal and long-term resource-related variations in soil microbial communities in wheat-based rotations of the Canadian prairie,” Soil Biology and Biochemistry, vol. 38, no. 8, pp. 2104–2116, 2006.
[24]
D. P. Oliver, J. E. Schultz, K. G. Tiller, and R. H. Merry, “The effect of crop rotation and tillage practices on cadmium concentration in wheat grain,” Australian Journal of Agricultural Research, vol. 44, no. 6, pp. 1221–1234, 1993.
[25]
C. A. Grant, M. A. Monreal, R. B. Irvine, R. M. Mohr, D. L. McLaren, and M. Khakbazan, “Preceding crop and phosphorus fertilization affect cadmium and zinc concentration of flaxseed under conventional and reduced tillage,” Plant and Soil, vol. 333, no. 1, pp. 337–350, 2010.
[26]
R. P. Zentner, G. P. Lafond, D. A. Derksen, and C. A. Campbell, “Tillage method and crop diversification: effect on economic returns and riskiness of cropping systems in a thin black chernozem of the Canadian prairies,” Soil and Tillage Research, vol. 67, no. 1, pp. 9–21, 2002.
[27]
C. A. Grant and L. D. Bailey, “The effect of tillage and KCl addition on pH, conductance, NO3-N, P, K and Cl distribution in the soil profile,” Canadian Journal of Soil Science, vol. 74, no. 3, pp. 307–314, 1994.
[28]
K. G. Tiller, D. P. Oliver, M. J. McLaughlin, et al., “Managing cadmium contamination of agricultural land,” in Remediation of Soils Contaminated by Metals, I. K. Iskandar, Ed., pp. 225–255, Science and Technology Letters, Northwood, UK, 1997.
[29]
A. J. Franzluebbers and F. M. Hons, “Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage,” Soil and Tillage Research, vol. 39, no. 3-4, pp. 229–239, 1996.
[30]
L. M. Shuman and D. V. McCracken, “Tillage, lime, and poultry litter effects on soil zinc, manganese, and copper,” Communications in Soil Science and Plant Analysis, vol. 30, no. 9-10, pp. 1267–1277, 1999.
[31]
X. Gao, F. Akhter, M. Tenuta, D. N. Flaten, E. J. Gawalko, and C. A. Grant, “Mycorrhizal colonization and grain Cd concentration of field-grown durum wheat in response to tillage, preceding crop and phosphorus fertilization,” Journal of the Science of Food and Agriculture, vol. 90, no. 5, pp. 750–758, 2010.
[32]
C. A. Grant, M. A. Monreal, R. B. Irvine, R. M. Mohr, D. L. Mclaren, and M. Khakbazan, “Crop response to current and previous season applications of phosphorus as affected by crop sequence and tillage,” Canadian Journal of Plant Science, vol. 89, no. 1, pp. 49–66, 2009.
[33]
S. R. Olsen, C. V. Cole, F. S. Watanabe, and L. A. Dean, “Estimation of available phosphorus in soils by extraction with sodium bicarbonate,” Circular number 939, USDA, 1954.
[34]
W. L. Lindsay and W. A. Norvell, “Development of a DTPA soil test for zinc, iron, manganese, and copper,” Soil Science Society of America Journal, vol. 42, no. 4, pp. 421–428, 1978.
[35]
R. L. Westerman, Soil Testing and Plant Analysis, Soil Science Society of America, Madison, Wis, USA, 1990.
[36]
X. Gao, K. R. Brown, G. J. Racz, and C. A. Grant, “Concentration of cadmium in durum wheat as affected by time, source and placement of nitrogen fertilization under reduced and conventional-tillage management,” Plant and Soil, vol. 337, no. 1, pp. 341–354, 2010.
[37]
R. D. Graham, R. M. Welch, D. A. Saunders et al., “Nutritious subsistence food systems,” Advances in Agronomy, vol. 92, pp. 1–74, 2007.
[38]
X. Gao and C. A. Grant, “Interactive effect of N fertilization and tillage management on Zn biofortification in durum wheat (Triticum durum),” Canadian Journal of Plant Science, vol. 91, no. 6, pp. 951–960, 2011.
[39]
K. R. J. Smettem, A. D. Rovira, S. A. Wace, B. R. Wilson, and A. Simon, “Effect of tillage and crop rotation on the surface stability and chemical properties of a red-brown earth (Alfisol) under wheat,” Soil and Tillage Research, vol. 22, no. 1-2, pp. 27–40, 1992.
[40]
C. G. Castillo, R. Rubio, J. L. Rouanet, and F. Borie, “Early effects of tillage and crop rotation on arbuscular mycorrhizal fungal propagules in an Ultisol,” Biology and Fertility of Soils, vol. 43, no. 1, pp. 83–92, 2006.
[41]
X. Gao, M. Tenuta, D. N. Flaten, and C. A. Grant, “Cadmium concentration in flax colonized by mycorrhizal fungi depends on soil phosphorus and cadmium concentrations,” Communications in Soil Science and Plant Analysis, vol. 42, no. 15, pp. 1882–1897, 2011.
[42]
M. H. Ryan, J. K. McInerney, I. R. Record, and J. F. Angus, “Zinc bioavailability in wheat grain in relation to phosphorus fertiliser, crop sequence and mycorrhizal fungi,” Journal of the Science of Food and Agriculture, vol. 88, no. 7, pp. 1208–1216, 2008.
[43]
A. Andersson and G. Simon, “Levels of Cd and some other trace elements in soils and crops as influenced by lime and fertilizer level,” Acta Agriculturae Scandinavica, vol. 4l, pp. 3–11, 1991.
[44]
J. J. Mortvedt, “Cadmium levels in soils and plants from some long-term soil fertility experiments in the United States of America,” Journal of Environmental Quality, vol. 16, no. 2, pp. 137–142, 1987.
[45]
M. A. Monreal, C. A. Grant, R. B. Irvine, R. M. Mohr, D. L. McLaren, and M. Khakbazan, “Crop management effect on arbuscular mycorrhizae and root growth of flax,” Canadian Journal of Plant Science, vol. 91, no. 2, pp. 315–324, 2011.
[46]
X. Gao, R. M. Mohr, D. L. McLaren, and C. A. Grant, “Grain cadmium and zinc concentrations in wheat as affected by genotypic variation and potassium chloride fertilization,” Field Crops Research, vol. 122, no. 2, pp. 95–103, 2011.
[47]
A. K. Joshi, J. Crossa, B. Arun et al., “Genotype × environment interaction for zinc and iron concentration of wheat grain in eastern Gangetic plains of India,” Field Crops Research, vol. 116, no. 3, pp. 268–277, 2010.
[48]
F. J. Zhao, Y. H. Su, S. J. Dunham et al., “Variation in mineral micronutrient concentrations in grain of wheat lines of diverse origin,” Journal of Cereal Science, vol. 49, no. 2, pp. 290–295, 2009.
