Impact of temperature on the dynamics of organic matter and on the soil-to-plant transfer of Cd, Zn and Pb in a contaminated agricultural soil

Abstract

Predicting the soil-to-plant transfer of metals in the context of global warming has become a major issue for food safety. It requires a better understanding of how the temperature alters the bioavailability of metals in cultivated soils. This study focuses on one agricultural soil contaminated by Cd, Zn and Pb. DGT measurements were performed at 10, 20 and 30 °C to assess how the bioavailability of metals was affected by a rise in soil temperature. A lettuce crop was cultivated in the same conditions to determine if the soil-to-plant transfer of metals increased with a rise in soil temperature. A gradual decline in Cd and Zn bioavailability was observed from 10 to 30 °C, which was attributed to more intense complexation of metals in the pore water at higher temperatures. Together with its aromaticity, the affinity of dissolved organic matter (DOM) for metals was indeed suspected to increase with soil temperature. One main output of the present work is a model which satisfactorily explains the thermal-induced changes in the characteristics of DOM reported in Cornu et al. (Geoderma 162:65-70, 2011) by assuming that the mineralization of initial aliphatic compounds followed a first-order reaction, increased with soil temperature according to the Arrhenius law, and due to a priming effect, led to the appearance of aromatic molecules. The soil-to-plant transfer of Cd and Zn was promoted at higher soil temperatures despite a parallel decrease in Cd and Zn bioavailability. This suggests that plant processes affect the soil-to-plant transfer of Cd and Zn the most when the soil temperature rises.

Effect of different amendments on trace metal bioavailability in agricultural soils and metal uptake on lettuce evaluated by Diffusive Gradients in Thin Films

“…However, results from our study show a significant correlation between the CE and uptake by lettuce for Cr (r = 0.528, p<0.05), Cu (r = 0.836, p<0.01) and Pb (r = 0.783, p<0.01), in front of the significant correlation between the CDGT and lettuces for Cu (r = 0.793, p<0.01) and Pb (r = 0.786, p<0.01). In contrast with other studies (Agbenin and Welp, 2012;Cornu et al, 2016), Cu and Pb were the trace metals for which a significant correlation (p<0.01) was found between CE and lettuces. To the best of our knowledge, this is the first study that correlates the calculated CE for Cr and its total content in lettuce.…”

Effects of temperature on soil geochemical properties and accumulation of heavy metals in Brassica napus

“…As a result, increased transpiration caused heavy metals to be unloaded from the xylem and phloem and delivered to various aboveground organs(Yamaji & Ma, 2014). Those results are in agreement with the results of other several studies(Cornu et al, 2016;Farhat et al, 2021;Ge et al, 2016;Li et al, 2012), which revealed a positive relationship between soil temperatures and the TF values of Zn, Cd, and Pb at the maturity stage. These data suggest that future elevated temperatures could induce more heavy metal uptake through the transport of heavy metals to the aerial parts of plants, such as leaves, grains, and fruits.…”

“…In general, it is known that elevated soil temperatures affect nutrient and microelement pathways by altering the solubility of trace elements and plant-microbe interactions (Almås AR, 2001;Miyasaka & Grunes, 1997;Muehe et al, 2019). Recent ndings (Cornu et al, 2016;Ge et al, 2016) showed that elevated temperature mobilizes soil-bound heavy metals by affecting soil geochemical properties including soil pH, soil organic matter (SOM), and cation-exchange capacity (CEC). The results of a previous study showed that an increase in soil temperature led to a lower dissolved organic matter concentration, and it promoted the soil-to-plant transfer of Cd and Zn in lettuce (Cornu et al, 2016).…”

“…Recent ndings (Cornu et al, 2016;Ge et al, 2016) showed that elevated temperature mobilizes soil-bound heavy metals by affecting soil geochemical properties including soil pH, soil organic matter (SOM), and cation-exchange capacity (CEC). The results of a previous study showed that an increase in soil temperature led to a lower dissolved organic matter concentration, and it promoted the soil-to-plant transfer of Cd and Zn in lettuce (Cornu et al, 2016). Changes in the soil temperature lead to altered microbial respiration rates, which can result in increased degradation of SOM degradation by the soil microorganisms (Sharma et al 2021).…”

Effects of temperature on soil geochemical properties and accumulation of heavy metals in rapeseed (Brassica napus)

“…In general, it is known that elevated soil temperatures affect nutrient and microelement pathways by altering the solubility of trace elements and plant-microbe interactions (Almås AR, 2001;Miyasaka & Grunes, 1997;Muehe et al, 2019). Recent studies (Cornu et al, 2016;Ge et al, 2016) showed that elevated temperature mobilizes soil-bound heavy metals by affecting soil geochemical properties including pH, soil organic matter (SOM), and cation-exchange capacity (CEC). A previous study showed that an increase in soil temperature led to a lower dissolved organic matter concentration, and it promoted the soil-to-plant transfer of Cd and Zn in lettuce (Cornu et al, 2016).…”