Modeling the toxicity of copper and zinc salts to wheat in 14 soils

Abstract

Interest is mounting in developing and utilizing soil-specific soil quality guidelines. This requires quantifying the effects that soil physicochemical properties have on various ecotoxicological endpoints, including phytotoxicity. To this end, 14 agricultural soils from Australia with differing soil properties were spiked with copper (Cu) and zinc (Zn) salts and used to conduct 21-d plant growth inhibition tests using wheat (Triticum aestivum L.) in pot trials. The toxicity of Cu and Zn was similar with 10% effect concentration (EC10) values ranging from 110 to 945 and from 235 to 965 mg/kg, respectively, while the corresponding median effect concentration (EC50) values ranged from 240 to 1,405 and 470 to 1,745 mg/kg, respectively. Copper toxicity values (EC10, EC20, and EC50) were best modeled by the logarithm of cation exchange capacity (CEC) and either soil pH or electrical conductivity. Zinc EC50 and EC20 values were best modeled using the logarithm of CEC, while the EC10 data were best modeled using soil pH and the logarithm of organic carbon. These models generally estimated toxicity within a factor of two of the measured values.

The importance of soil solution chemistry to nickel toxicity on barley root elongation

“…However, the environmental risks posed by metals are not only a function of their overall presence in soils, but also of their chemical speciation. There have been a number of studies into the effects of metal toxicity on plants (Jolanta and Stanislaw, 2004;Daoust et al, 2006;Lock et al, 2007a;Warne et al, 2008;Papazoglou, 2011). For example, Rooney et al (2007) reported that soil cation exchange capacity was the best single predictor for the median effective concentration (EC50) of added nickel (Ni) and the EC50 ranged from 52 to 1929 mg kg -1 and from 17 to 920 mg kg -1 in tests on barley and tomato plants, respectively.…”

Assessment of cadmium, zinc and lead contamination in leaf and root of four various species

“…Concentrations of Zn found in contaminated soils frequently exceed the limits required to be as a nutrient and may cause phytotoxicity. Zn concentrations in the range of 150-300 mg/kg have been measured in polluted soils (Devries et al 2002;Warne et al 2008). High levels of Zn in soil inhibit many metabolic functions of plants, resulting in retarded growth and cell senescence.…”

Lead toxicity thresholds in 17 Chinese soils based on substrate-induced nitrification assay

“…Despite these limitations, normalization relationships could play a crucial role in risk and hazard assessment (Li et al, 2011;Warne et al, 2008), as they can provide estimates of the toxicity of Pb toward soil nitrification in soils when experimentally derived values are lacking. They could also be used to normalize toxicity for use in deriving soil quality guidelines (Li et al, 2010;Warne et al, 2008).…”

“…They could also be used to normalize toxicity for use in deriving soil quality guidelines (Li et al, 2010;Warne et al, 2008). The soil quality guidelines could be derived for soil nitrification using the relationships and could be obtained for other soil microbial processes for which there are no similar relationships by simply normalizing the data using the gradient.…”

“…The soil quality guidelines could be derived for soil nitrification using the relationships and could be obtained for other soil microbial processes for which there are no similar relationships by simply normalizing the data using the gradient. The advantages of these relationships are that they are based on relatively simple-to-measure soil properties, they are easy to use, they are cost-effective compared with conducting toxicity tests, and provide accurate estimates of laboratory-based toxicity (Warne et al, 2008). The usefulness of these relationships indicates that it may be possible to develop other normalization relationships for other countries in Europe, Oceania or other continents.…”