Effect of exogenous phosphate on the lability and phytoavailability of arsenic in soils

Abstract

The effect of exogenous phosphate (P, 200 mg⋅kg soil) on the lability and phytoavailability of arsenic (As) was studied using the diffusive gradients in thin films (DGT) technique. Lettuce were grown on the As-amended soils following the stabilization of soil labile As after 90 days incubation. Phosphate (P) application generally facilitated plant growth except one grown on P-sufficient soil. Soil labile As concentration increased in all the soils after P application due to a competition effect. Plant As concentration increased in red soils collected from Hunan Province, while decreases were observed in the other soils. Even though, an overall trend of decrease was obtained in As phytoavailability along with the increase of DGT-measured soil labile P/As molar ratio. The functional equation between P/As and As phytoavailability provided a critical value of 1.7, which could be used as a guidance for rational P fertilization, thus avoiding overfertilization.

Can Diffusive Gradients in Thin Films (DGT) Technique and Chemical Extraction Methods Successfully Predict both Zn Bioaccumulation Patterns in Plant and Leaching to Groundwater in Soils Amended with Engineered ZnO Nanoparticles?

“…They concluded that equilibrium-based soil metal extraction procedures typically showed poor correlations with shoot metal concentrations. Unlike in the chemical extraction approaches, the DGT technique takes into consideration the kinetic processes that take place between the soil solid and solution phases (Wang et al 2018), including the resupply of metals from the solid phase to the solution phase (Dai et al 2018). Small ZnO NPs can pass through the open pore diffusive layer used in standard DGT devices and can be retained by the binding resin layer (Pouran et al 2014).…”

Sustainable Conservation Tillage Improves Soil Nutrients and Reduces Nitrogen and Phosphorous Losses in Maize Farmland in Southern China

“…Soil total N (TN) was determined by the macro-Kjeldahl wet oxidation method [15]. Soil Alkaline N (AN) content was determined using alkaline hydrolysis diffusion method [16]. Soil TOC was estimated using the potassium dichromate volumetric method [17].…”

Assessment of potential dietary toxicity and arsenic accumulation in two contrasting rice genotypes: Effect of soil amendments

“…The toxicity of arsenic is likely due to the anaerobic environment in paddy fields where reducing redox conditions favour the bioavailability of arsenite which is more toxic than arsenate(Zia et al, 2017). This rice specific aspect affects both arsenic translocation and seed setting and consequently overall yield(Finnegan and Chen, 2012;Wang et al, 2018;Islam, S. et al, 2017).…”