Introduction
Materials and methods
Secondary P-fertilizers
Dry matter (%) | P2O5 (%) | PNAC (%) | PCIT (%) | PW (%) | N (%) | K (%) | Mg (%) | Ca (%) | S (%) | |
---|---|---|---|---|---|---|---|---|---|---|
Struvite | 100 | 26.6 | 94 | 99 | 4 | 4.7 | 0.08 | 9.3 | 0.7 | 0.1 |
SSA-Mg | 99.8 | 13.9 | 28 | 88 | 1 | < 0.1 | 0.25 | 6.2 | 12.3 | 1 |
SSA-Na | 100 | 12.9 | 99 | 100 | 10 | < 0.1 | 0.58 | 1.4 | 9.9 | 1.1 |
Pot experiment
Soil sample preparation for XANES analyses
References preparation for XANES analyses
μ-XRF and XANES microspectroscopy
Results and discussion
Pot experiment with maize on a nearly neutral and an acidic soil
P uptake (mg P pot−1) | N uptake (mg N pot−1) | |
---|---|---|
Control | 47.6 ± 12.7 | 600.0 ± 177.2 |
SSA-Mg | 57.1 ± 11.8 | 720.0 ± 141.5 |
SSA-Na | 132.7 ± 5.1 | 1175.3 ± 93.0 |
Struvite | 152.0 ± 13.4 | 1324.4 ± 145.9 |
TSP | 135.4 ± 24.2 | 1273.6 ± 268.1 |
Before sowing (mg kg−1) | After harvest (mg kg−1) | |
---|---|---|
Control | 17 | 12 |
SSA-Mg | 43 | 32 |
SSA-Na | 103 | 93 |
Struvite | 122 | 78 |
TSP | 109 | 79 |
Macro-XANES spectroscopy of soil fractions < 200 µm
Different P forms in various soil fractions identified by macro-XANES spectroscopy
Detection of ammonium phosphate formation by micro-XRF/XANES spectroscopy
Linear combination fitting of macro-XANES spectra
Effect of the chemical state of nitrogen on P uptake
NH4-N | NO3-N | |
---|---|---|
Control | 14.5 | 85.5 |
SSA-Mg | 14.6 | 85.4 |
SSA-Na | 14.8 | 85.2 |
Struvite | 26.2 | 73.8 |
TSP | 14.6 | 85.4 |