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Abstract
Soil samples from the Alberta Environmentally Sustainable Agriculture (AESA) Soil Quality Resource Monitoring Program Benchmark Sites were analyzed for 30 micronutrients and trace elements. The broad scan of micronutrient and trace elements provides useful baseline information regarding the variability and range of element concentrations within ecoregions, soil types and landscapes. This report describes the influence of ecoregions, soil properties and historic management practices on boron (B), chloride (Cl), cobalt (Co), molybdenum (Mo), nickel (Ni), silicon (Si), chromium (Cr), cadmium (Cd) and selenium (Se). Significant differences between ecoregions were found in the o-15 cm soil samples for the elements B, Cd, and Mo, as well as for Cd in the 15-30 cm depth. Slope position had a significant effect on B, Ni, Co, Si, Cd and Se; and in most instances the highest values occurred in the lower slope position. Significant (p>0.05) differences between other elements and selected soil properties were found for B, Mo, Ni, Co, Cd and Se. Management did not appear to have an impact on the micronutrients and trace elements, although management practices that influence soil organic matter could influence some elements. No evidence of toxic levels of B, Mo, Cr or Cd was noted at any of the benchmark locations, although Ni may have the potential of causing phytotoxicity at one site. Many of the sites may deficient in Cl for crop production and low Se may be an issue for livestock production at some of the locations. Further investigation, including plant tissue analysis is recommended at some sites for the elements Ni, Si, Cr, Cd and Se. The literature does not provide well-defined criteria for determining deficiency or toxicity for many trace elements. While there was limited information for some of the elements, the extraction methods utilized were different from methods used in this study, making comparisons difficult. Sampling the upper, mid and lower slope positions at each of the sites provided valuable information on the distribution of the elements within the landscape. Micronutrient and trace element analysis of some crop samples would provide useful supplemental information for interpreting the soil data |
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