Complex Forms of Soil Organic Phosphorus鈥揂 Major Component of Soil Phosphorus
详细信息 查看全文
- 作者：Timothy I. McLaren ; Ronald J. Smernik ; Mike J. McLaughlin ; Therese M. McBeath ; Jason K. Kirby ; Richard J. Simpson ; Christopher N. Guppy ; Ashlea L. Doolette ; Alan E. Richardson
- 刊名：Environmental Science & Technology
- 出版年：2015
- 出版时间：November 17, 2015
- 年：2015
- 卷：49
- 期：22
- 页码：13238-13245
- 全文大小：340K
- ISSN：1520-5851
文摘
Phosphorus (P) is an essential element for life, an innate constituent of soil organic matter, and a major anthropogenic input to terrestrial ecosystems. The supply of P to living organisms is strongly dependent on the dynamics of soil organic P. However, fluxes of P through soil organic matter remain unclear because only a minority (typically <30%) of soil organic P has been identified as recognizable biomolecules of low molecular weight (e.g., inositol hexakisphosphates). Here, we use 31P nuclear magnetic resonance spectroscopy to determine the speciation of organic P in soil extracts fractionated into two molecular weight ranges. Speciation of organic P in the high molecular weight fraction (>10 kDa) was markedly different to that of the low molecular weight fraction (<10 kDa). The former was dominated by a broad peak, which is consistent with P bound by phosphomonoester linkages of supra-/macro-molecular structures, whereas the latter contained all of the sharp peaks that were present in unfractionated extracts, along with some broad signal. Overall, phosphomonoesters in supra-/macro-molecular structures were found to account for the majority (61% to 73%) of soil organic P across the five diverse soils. These soil phosphomonoesters will need to be integrated within current models of the inorganic鈥搊rganic P cycle of soil-plant terrestrial ecosystems.