The plant availability of phosphorus from thermo-chemically treated sewage sludge ashes as studied by 33P labeling techniques
Abstract
Aims
Phosphorus resources have to be managed sustainably and therefore the recycling of P from waste streams is essential. A thermo-chemical recycling process has been developed to produce a P fertilizer from sewage sludge ash (SSA) but its plant availability is unknown.
Methods
Two SSA products prepared with either CaCl2 (SSACa) or MgCl2 (SSAMg) as chemical reactant during the thermal treatment were mixed with three soils previously labeled with 33P. Reference treatments with water-soluble P added at equal amounts of total P were included. The transfer of P from SSACa and SSAMg to Lolium multiflorum or P pools of sequentially extracted soil-fertilizer incubations were quantified.
Results
The shoot P uptake from SSAMg was higher than from SSACa. For SSAMg the relative effectiveness compared to a water-soluble P fertilizer was 88 % on an acidic and 71 % on a neutral soil but only 4 % on an alkaline soil. The proportion of P derived from the fertilizer in the plant and in the first two extraction pools of soil-fertilizer incubations were strongly correlated, suggesting that it is sufficient to conduct an incubation study to obtain robust information on plant P availability.
Conclusions
We conclude that under acidic to neutral conditions SSAMg presents an appropriate alternative to conventional P fertilizers and the dissolution of P from SSAMg seems to be governed by protons and cations in the soil solution. Mehr anzeigen
Persistenter Link
https://doi.org/10.3929/ethz-b-000075271Publikationsstatus
publishedExterne Links
Zeitschrift / Serie
Plant and SoilBand
Seiten / Artikelnummer
Verlag
SpringerThema
Sewage sludge ash; 33Plabeling; Recycling fertilizer; Radioisotopes; Italian ryegrass; Sequential extractionOrganisationseinheit
03427 - Frossard, Emmanuel / Frossard, Emmanuel
Anmerkungen
It was possible to publish this article open access thanks to a Swiss National Licence with the publisher.