Chemotaxis of rhizosphere Pseudomonas sp. induced by foliar spraying of lanthanum reduces cadmium uptake by pakchoi.

Foliar application of rare earth micronutrient of lanthanum (La) exhibits great potential in reducing cadmium (Cd) uptake in crops, the underlying mechanisms controlling the interaction between Cd toxicity-relieved crops and soil microbiota are poorly understood. In this study, LaCl with the concentrations of 10 and 30 μM was sprayed on pakchoi (Brassica chinensis L.) planting on Cd contaminated solution and soil to determine the changes of root metabolites and rhizosphere bacterial communities.

Integrating rhizosphere bacterial structure and metabolites with soil Cd availability in different parent paddy soils.

Soil bacterial community structure and rhizosphere metabolites are important pathways for rice to respond to external Cd stress. The specific correlations between these microorganisms, metabolites and inherent soil properties, as well as the mechanisms they utilize to regulate Cd availability across different parent soils remain underexplored, emphasizing the need for deeper understanding to inform effective soil management strategies. In this study, five typical parent soils with large differences in properties (quaternary red clay soil (hereby defined as Q), granite soil (G), river sandy mud (R), yellow mud soil (Y), stucco field (S)) in Chinese paddy soils were collected, and extra Cd were added (CK: 0 mg·kg, Cd: 2.

Ecological risk threshold for chromium in Chinese soils and its prediction models.

The derivation of chromium (Cr) ecological risk thresholds in soils remains limited, despite their importance as measurement standards and indicators for enacting soil protection policies. In this study, toxicity of Cr in soil to different species was tested based on Log-Logistic dose-effect relationship. On this basis, combined with Cr toxicity measurement data in literature, the ecological risk threshold HC for protecting 95% species safety in soils with different properties was obtained by fitting species sensitivity distribution curve (SSD).

The environmental risk threshold (HC) for Cd remediation in Chinese agricultural soils.

Given the increasing concern over Cd contamination of agricultural soils in China, reducing the availability of the toxic metal has become an important remedial strategy. However, the lack of a unified evaluation framework complicates the assessment of remediation efficiency of different practices. Here, we evaluated the general extraction method (GEM) of available Cd in nine typical soil types by comparing extraction agents, including CaCl, EDTA, Mehlich-Ⅲ, HCl and DTPA.