Trace Element Concentrations of Selected Soils and Fertilizers in Saskatchewan, Canada

Limited information is available on the trace element contents of soils and crops in Saskatchewan. Trace elements, to a large extent, are derived from soil parent materials and partially from anthropogenic activities, such as agricultural application of fertilizers. The objective of this study was to establish levels of trace element concentrations of the surface horizons and parent materials of selected soils, fertilizers, and durum wheat (Triticum durum Desf.). Inductively coupled plasma mass spectrometry (ICP-MS) having the capacity to determine 60 elements simultaneously at very low detection levels was used. Trace elements for this work are among the most frequently reported in the recent literature. We found a positive relationship between the total contents of trace elements and percent of clays in the soils, except Se. This suggests that the major part of the elements studied are associated with the clay minerals in soils. In two Regina heavy clay soils, total Cu, Zn, Se, and Pb were higher in the surface soil than the subsoil, but this increase was statistically not significant. All the elements, except Zn, Cd, and Pb, were depleted in soils that have lower clay content in the surface horizon than the parent material. Soils having similar clay contents in the surface horizon and subsoil, total V, Cr, Co, Ni, Zn, Cd, Sn, Sb, Tl, and Pb concentrations were higher in the surface horizon, relative to parent material. Only Zn and Cd increases were significant. Enrichment of elements in the surface horizons was, in part, attributed to anthropogenic additions. Experiments with EDTA and DTPA extraction techniques showed that almost half of Co, As and Cd, and other elements in fertilizers were between 4 and 50% in somewhat available form for plants indicating their potential for soil pollution. Contribution no. R768 from the Saskatchewan Centre for Soil Research, Univ. of Saskatchewan, Saskatoon, SK S7N 5A8.