TY - JOUR A1 - Vogel, Christian A1 - Helfenstein, J. A1 - Massey, M. A1 - Sekine, R. A1 - Kretzschmar, R. A1 - Beiping, L. A1 - Peter, T. A1 - Chadwick, O. A1 - Tamburini, F. A1 - Rivard, C. A1 - Herzel, Hannes A1 - Adam, Christian A1 - Pradas del Real, A. A1 - Castillo-Michel, H. A1 - Zuin, L. A1 - Wang, D. A1 - Félix, R. A1 - Lassalle-Kaiser, B. A1 - Frossard, E. T1 - Microspectroscopy reveals dust-derived apatite grains in acidic, highly-weathered Hawaiian soils N2 - Dust deposition is an important source of phosphorus (P) to many ecosystems. However, there is little evidence of dust-derived P-containing minerals in soils. Here we studied P forms along a well-described climatic Gradient on Hawaii, which is also a dust deposition gradient. Soil mineralogy and soil P forms from six sites along the climatic gradient were analyzed with bulk (X-ray diffraction and P K-edge X-ray absorption near edge structure) and microscale (X-ray fluorescence, P K-edge X-ray absorption near edge structure, and Raman) analysis methods. In the wettest soils, apatite grains ranging from 5 to 30 μm in size were co-located at the micro-scale with quartz, a known continental dust indicator suggesting recent atmospheric deposition. In addition to co-location with quartz, further evidence of dust-derived P included backward trajectory modeling indicating that dust particles could be brought to Hawaii from the major global dust-loading areas in central Asia and northern Africa. Although it is not certain whether the individual observed apatite grains were derived from long-distance transport of dust, or from local dust sources such as volcanic ash or windblown fertilizer, these observations offer direct evidence that P-containing minerals have reached surface layers of highly-weathered grassland soils through atmospheric deposition. KW - Phosphorus KW - soil KW - microspectroscopy KW - Raman spectroscopy KW - XANES spectroscopy KW - x-ray diffraction PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-511522 SN - 0166-0918 SN - 1872-6259 VL - 381 SP - 114681-1 EP - 114681-11 PB - Elsevier CY - Amsterdam AN - OPUS4-51152 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vogel, Christian A1 - Sekine, R. A1 - Huang, J. A1 - Steckenmesser, D. A1 - Steffens, D. A1 - Huthwelker, T. A1 - Borca, C. A1 - Pradas del Real, A. A1 - Castillo-Michel, H. A1 - Adam, Christian T1 - Effects of a nitrification inhibitor on nitrogen species in the soil and the yield and phosphorus uptake of maize N2 - Phosphorus (P) resource availability is declining and the efficiency of applied nutrients in agricultural soils is becoming increasingly important. This is especially true for P fertilizers from recycled materials, which often have low plant availability. Specific co-fertilization with ammoniumcan enhance P plant availability in soils amended with these P fertilizers, and thus the yield of plants. To investigate this effect, we performed a pot experiment with maize in slightly acidic soil (pH 6.9) with one water-soluble (triple superphosphate [TSP]) and two water-insoluble (sewage sludge-based and hyperphosphate [Hyp]) P fertilizers and anammoniumsulfate nitrate with or without a nitrification inhibitor (NI). The dry matter yield of maize was significantly increased by the NI with the Hyp (from 14.7 to 21.5 g/pot) and TSP (from 40.0 to 45.4 g/pot) treatments. Furthermore, P uptake was slightly increased in all three P treatments with the NI, but not significantly. Olsen-P extraction and P K-edge micro-X-ray absorption near-edge structure (XANES) spectroscopy showed that apatite-P of the water insoluble P fertilizers mobilized during the plant growth period. In addition, novel nitrogen (N) K-edge micro-XANES spectroscopy and the Mogilevkina method showed that the application of an NI increased the fixation of ammonium in detectable hot spots in the soil. Thus, the delay in the nitrification process by the NI and the possible slow-release of temporarily fixed ammoniumin the soil resulted in a high amount of plant available Ammonium in the soil solution. This development probably decreases the rhizosphere pH due to release of H+ by plants during ammoniumuptake, whichmobilizes phosphorus in the amended soil and increases the dry matter yield of maize. This is especially important for water-insoluble apatite-based P fertilizers (conventional and recycled), which tend to have poor plant availability. KW - Fertilzer KW - Phosphorus recovery KW - Ammonium KW - Nitrification inhibitor KW - XANES spectroscopy KW - Diffusive gradients in thin films (DGT) PY - 2020 U6 - https://doi.org/10.1016/j.scitotenv.2020.136895 SN - 1879-1026 VL - 715 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam AN - OPUS4-50477 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -