| Title |
Increasing phosphorus fertilizer value of recycled iron phosphates by prolonged flooding and organic matter addition |
| ID_Doc |
6453 |
| Authors |
Saracanlao, RJ; VAN Ryckel, H; Verbeeck, M; Everaert, M; Smolders, E |
| Title |
Increasing phosphorus fertilizer value of recycled iron phosphates by prolonged flooding and organic matter addition |
| Year |
2024 |
| Published |
Pedosphere, 34, 3 |
| DOI |
10.1016/j.pedsph.2023.03.020 |
| Abstract |
Iron (Fe) minerals are commonly used to remove phosphorus (P) from waste streams, producing P-loaded Fe(III) oxides or Fe(II) phosphate minerals (e.g., vivianite). These minerals may be used as fertilizers to enhance P circularity if solubilized in soil. Here, we tested the P fertilizer value of recycled Fe phosphates (FePs) in a pot trial and in an incubation experiment, hypothesizing that P release from FePs is possible under Fe(III)-reducing conditions. First, a pot trial was set up with rice (Oryza sativa) in all combinations of soil flooding or not, three P-deficient soils (acid, neutral, and calcareous), and six FePs (three Fe(III)Ps and three Fe(II)Ps) referenced to triple superphosphate (TSP) or zero amendments. Shoot P uptake responded to TSP application in all treatments but only marginally to FePs. The redox potential did not decrease to -200 mV by flooding for a brief period (13 d) during the pot trial. A longer incubation experiment (60 d) was performed, including a treatment of glutamate addition to stimulate reductive conditions, and P availability was assessed with CaCl2 extraction of soils. Glutamate addition and/or longer incubation lowered soil redox potential to < -100 mV. On the longer term, Fe(III) minerals released P, and adequate P was reached in the calcareous soil and in the neutral soil amended with Fe(III)P-sludge. It can be concluded that prolonged soil flooding and organic matter addition can enhance the P fertilizer efficiency of FePs. Additionally, application of FeP in powder form may enhance P availability. |
| Author Keywords |
agronomic efficiency; circular economy; P-loaded Fe(III) oxides; paddy soil; vivianite; redox |
| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:001256437800001 |
| WoS Category |
Soil Science |
| Research Area |
Agriculture |
| PDF |
https://lirias.kuleuven.be/bitstream/20.500.12942/721403/2/Dec%2019_revised%20main%20document_pedosphere.docx
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