@article{TranMaiNguyenetal.2018,
  author    = {Tran, C. T. and Mai, N. T. and Nguyen, V. T. and Nguyen, H. X. and Meharg, A. and Carey, M. and Dultz, S. and Marone, F. and Cichy, Sarah Bettina and Nguyen, Minh N.},
  title     = {Phytolith-associated potassium in fern},
  series = {Soil use and Management},
  volume    = {34},
  journal   = {Soil use and Management},
  number    = {1},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {0266-0032},
  doi       = {10.1111/sum.12409},
  pages     = {28 -- 36},
  year      = {2018},
  abstract  = {In recent time, phytoliths (silicon deposition between plant cells) have been recognized as an important nutrient source for crops. The work presented here aims at highlighting the potential of phytolith-occluded K pool in ferns. Dicranopteris linearis (D.linearis) is a common fern in the humid subtropical and tropical regions. Burning of the fern D.linearis is, in slash-and-burn regions, a common practice to prepare the soil before planting. We characterised the phytolith-rich ash derived from the fern D.linearis and phytolith-associated potassium (K) (phytK), using X-ray tomographic microscopy in combination with kinetic batch experiments. D.linearis contains up to 3.9g K/kgd.wt, including K subcompartmented in phytoliths. X-ray tomographic microscopy visualized an interembedding structure between organic matter and silica, particularly in leaves. Corelease of K and Si observed in the batch experiments confirmed that the dissolution of ash phytoliths is one of major factors controlling K release. Under heat treatment, a part of the K is made available, while the remainder entrapped into phytoliths (ca. 2.0-3.3\%) is unavailable until the phytoliths are dissolved. By enhanced removal of organic phases, or forming more stable silica phases, heat treatment changes dissolution properties of the phytoliths, affecting K release for crops and soils. The maximum releases of soluble K and Si were observed for the phytoliths treated at 500-800 degrees C. For quantitative approaches for the K provision of plants from the soil phytK pool in soils, factors regulating phytolith dissolution rate have to be considered.},
  language  = {en}
}
@article{FrickSchuesslerSommeretal.2018,
  author    = {Frick, Daniel Alexander and Sch{\"u}ßler, Jan Arne and Sommer, Michael and von Blanckenburg, Friedhelm},
  title     = {Laser Ablation In Situ Silicon Stable Isotope Analysis of Phytoliths},
  series = {Geostandards and geoanalytical research},
  volume    = {43},
  journal   = {Geostandards and geoanalytical research},
  number    = {1},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1639-4488},
  doi       = {10.1111/ggr.12243},
  pages     = {77 -- 91},
  year      = {2018},
  abstract  = {Silicon is a beneficial element for many plants and is deposited in plant tissue as amorphous bio-opal called phytoliths. The biochemical processes of silicon uptake and precipitation induce isotope fractionation: the mass-dependent shift in the relative abundances of the stable isotopes of silicon. At the bulk scale, delta Si-30 ratios span from -2 to +6 parts per thousand. To further constrain these variations in situ, at the scale of individual phytolith fragments, we used femtosecond laser ablation multi-collector inductively coupled plasma-mass spectrometry (fsLA-MC-ICP-MS). A variety of phytoliths from grasses, trees and ferns were prepared from plant tissue or extracted from soil. Good agreement between phytolith delta Si-30 ratios obtained by bulk solution MC-ICP-MS analysis and in situ isotope ratios from fsLA-MC-ICP-MS validates the method. Bulk solution analyses result in at least twofold better precision for delta Si-30 (2s on reference materials <= 0.11 parts per thousand) over that found for the means of in situ analyses (2s typically <= 0.24 parts per thousand). We find that bushgrass, common reed and horsetail show large internal variations up to 2 parts per thousand in delta Si-30, reflecting the various pathways of silicon from soil to deposition. Femtosecond laser ablation provides a means to identify the underlying processes involved in the formation of phytoliths using silicon isotope ratios.},
  language  = {en}
}