Diffusive gradients in thin films predicts crop response better than calcium-acetate-lactate extraction

Nutrient Cycling in Agroecosystems - Soil P testing has been widely used to predict crop yields, P uptake, and fertilizer demands in agriculture. Diffusive gradients in thin films (DGT) provides a...     

Developing decision support tools for the selection of “gentle” remediation approaches

A range of tools have been proposed to support decision making in contaminated land remediation. From a European perspective it is clear, however, that there are considerable national differences in the decision support process, and more generally in the extent to which this process supports the selection of less invasive, alternative remediation options such as phytoremediation, in situ immobilisation etc. (referred to here as “gentle” remediation technologies). In this paper we present results from the recently completed European Union ERANET SNOWMAN project SUMATECS (Sustainable Management of Trace Element Contaminated Sites), and critically review available decision support tools in terms of their fitness for purpose for the application of gentle remediation technologies. Stakeholder feedback indicates a lack of knowledge amongst stakeholders of currently available decision support tools. We propose that decision support which focuses on gentle remediation is more strongly incorporated into existing, well-established (national) decision support tools / decision-frameworks, to promote more widespread use and uptake.     

Long-term soil accumulation of potentially toxic elements and selected organic pollutants through application of recycled phosphorus fertilizers for organic farming conditions

The pollutant input and the risk of contamination by long-term application of recycled P fertilizers (RPFs) in European agricultural soils were estimated by a mass balance approach. Calculations based on literature data were carried out for the potentially toxic elements (PTEs) Cd, Cr, Cu, Ni, Pb, Zn and for the persistent organic pollutants (POPs) PCBs, PAHs and polychlorinated dibenzo-dioxins and -furans. The PTE accumulation estimation during 200 years of fertilizer application, equivalent to 11 kg P ha^?1 year^?1, the mean P export via harvested products on European stockless organic farms, regarded soil background concentrations and proposed threshold concentrations. For PTEs, inputs were fertilizer application, atmospheric deposition and liming, output processes were leaching and crop harvest. The effect of varying site conditions was assessed by considering two precipitation excess (F) values and two soil pH values. For POPs, fertilizer application and the half-life time were considered. The PTE accumulation risk was low for most RPFs. For the analysed POPs no accumulation was found. The highest accumulation was found for all PTEs at pH 7 and F = 0.1 m year^?1, the lowest at pH 5 and F = 0.3 m year^?1. A high P concentration in fertilizers resulted in a low PTE flow per unit of P. Composts had the highest PTE accumulation risk due to lowest P contents. Struvite, meat and bone meal, digestate of catering waste, ash and biosolids would be better suited as P fertilizers. The use of fertilizers should be regulated based on their pollutant-to-nutrient ratio.