Identification and quantitation of P compounds and its transformation products in a dual P band using X-ray absorption near edge spectroscopy (XANES)

使用 X 射线吸收近边光谱 (XANES) 对双 P 波段中的 P 化合物及其转化产物进行鉴定和定量

• 批准号: 349837-2007
• 负责人: Akinremi, OlalekanOluwole
• 金额: $ 1.49万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2008
• 资助国家: 加拿大
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=401927
• 关键词: Identification; quantitation; compounds; its; transformation

The long-term objective of this study is to significantly increase the efficiency of fertilizer phosphorus uptake by the crop. In the short term, our objectives are i) to identify and quantify the phosphorus compounds and sulphate salts that are formed in dual bands of P fertilizer using X-ray absorption near edge structure (XANES) spectroscopy; ii) to follow the transformation of these initial P compounds in time using XANES and iii) to determine those salt combinations that will increase P solubility and thereby P availability to plants. Low phosphate fertilizer efficiency in high pH soils is primarily due to the slowing down of P movement in the soil-P fertilizer reaction zone. This is caused by rapid reaction of the applied P with soil components such as exchangeable Ca2+ and Mg2+ displaced into soil solution. Measures that have been taken to rectify this problem include the modification of the chemical environment of soil-P fertilizer reaction zone through the co-application of non-phosphatic salts with fertilizer P. In a recently completed study, we demonstrated that the application of sulphate or carbonate salts of ammonium with either monoammonium phosphate or monopotassium phosphate increased the solubility and chemical diffusion of phosphorus (Akinremi et al. 2006). This enhancement was attributed to anionic competition between sulphate or carbonate and P for the displaced exchangeable or solubilized calcium. We hypothesized that the formation of CaSO4 reduced the precipitation of P thereby increasing solution P. However, the chemical form of the precipitated P is unknown and there is no direct evidence for the presence CaSO4 in the soil. The proposed study will demonstrate the application of "state of the art" spectroscopic technique to finding practical solution of low phophorus fertilizer use efficiency. Our ability to identify and quantify the P minerals that are formed in a dual band will aid our efforts at finding the right formula for improving the fertilizer use efficiency of P by the crop. An increase in phosphorus fertilizer use efficiency will provide economic and environmental benefits for Canadian farmers through reduced input cost and reduced residual soil phosphorus.

这项研究的长期目标是显着提高作物对肥料磷的吸收效率。短期内，我们的目标是 i) 使用 X 射线吸收近边结构 (XANES) 光谱来识别和量化磷肥双谱带中形成的磷化合物和硫酸盐； ii) 使用 XANES 及时跟踪这些初始磷化合物的转化，以及 iii) 确定那些将增加磷溶解度并从而提高植物磷利用率的盐组合。高pH值土壤中磷肥效率低主要是由于土壤-磷肥反应区磷移动减慢所致。这是由于施入的磷与土壤成分（如可交换的 Ca2+ 和 Mg2+）快速反应而转移到土壤溶液中造成的。为纠正这一问题而采取的措施包括通过非磷酸盐与磷肥的共同施用来改变土壤磷肥反应区的化学环境。在最近完成的一项研究中，我们证明了硫酸盐的施用或铵的碳酸盐与磷酸一铵或磷酸二氢钾增加了磷的溶解度和化学扩散（Akinremi 等人，2006 年）。这种增强归因于硫酸盐或碳酸盐与磷之间对取代的可交换或溶解钙的阴离子竞争。我们假设 CaSO4 的形成减少了 P 的沉淀，从而增加了溶液 P。然而，沉淀 P 的化学形式尚不清楚，也没有直接证据表明土壤中存在 CaSO4。拟议的研究将展示“最先进的”光谱技术的应用，以寻找低磷肥利用率的实际解决方案。我们识别和量化双带中形成的磷矿物质的能力将有助于我们努力寻找正确的配方，以提高作物对磷的肥料利用效率。磷肥利用率的提高将通过降低投入成本和减少土壤残留磷来为加拿大农民带来经济和环境效益。