Biosolids phosphorus forms, transformation and bioavailability in soil

土壤中生物固体磷的形态、转化和生物利用度

• 批准号: 402440-2011
• 负责人: Sharifi, Mehdi
• 金额: $ 1.68万
• 依托单位: Trent University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=529570
• 关键词: Biosolids; phosphorus; forms; transformation; bioavailability

Recycling of phosphous (P) is exteremly important as the phosphate industry predicts exhaustion of available P reserves in next 100 to 250 years. Land application of biosolids on agricultural lands helps closing the rural-urban nutrient cycle. However, to effectively manage biosoilds P in agro-ecosystems, a better understanding of biosolids P forms, transformation and bioavailability is required. Improper application rates can result in either losses of crop yield or P accumulation in soil with increased environmental risks. Total concentrations of P in biosolids generally fall in range of 1 to 5% dry weight basis, 70 to 90% of which is in inorganic forms. Understanding the bioavailability of biosolids P after addition to soil requires an understanding of not only the forms and amounts of P in these materials, but also the forms and amounts of elements or materials that can modify P behaviour, kinetics of P transformation and its interactions with soil and plant roots. Traditional speciation methods provide limited insight into identification of biosolids P compounds. As an alternative to chemical extraction, advanced spectroscopic techniques have been recently offered for characterization of P species in soil and amendments. The X-ray Absorption Near-Edge Structure technique is one of the latest spectroscopic tools for solid phase speciation of P. This technique can distinguish between precipitated and adsorbed phases of P. Different P compounds in biosolids have also been identified using P-31 Nuclear Magnetic Resonance spectroscopy, a technique that provides direct molecular and structural characterization of organic P. Through greenhouse and field study, biosolids P forms will be characterized using advanced analytical techniques. Effects of soil properties, moisture and temperature on biosolid P transformation over the study period will be evaluated. As well, biosolids P transformation in soil and rhizosphere, its bioavailability and mobility in the soil will be investigated. Finally, the residual effect of applied biosolid P in the soil will be quantified.

磷 (P) 的回收极其重要，因为磷酸盐行业预计可用磷储量将在未来 100 至 250 年内耗尽。在农田上施用生物固体有助于闭合城乡养分循环。然而，为了有效管理农业生态系统中的生物固体磷，需要更好地了解生物固体磷的形式、转化和生物利用度。施用量不当可能会导致作物产量损失或土壤中磷积累，从而增加环境风险。生物固体中磷的总浓度通常在干重的 1% 至 5% 范围内，其中 70% 至 90% 为无机形式。了解生物固体磷添加到土壤后的生物利用度不仅需要了解这些材料中磷的形式和含量，还需要了解可以改变磷行为的元素或材料的形式和含量、磷转化动力学及其与土壤和植物根系的相互作用。传统的形态分析方法对生物固体 P 化合物的鉴定提供的见解有限。作为化学提取的替代方案，先进的光谱技术最近已被用于表征土壤和改良剂中的磷形态。 X 射线吸收近边结构技术是用于 P 固相形态分析的最新光谱工具之一。该技术可以区分 P 的沉淀相和吸附相。还使用 P-31 核磁共振波谱技术鉴定了生物固体中的不同 P 化合物，该技术提供了有机 P 的直接分子和结构表征。通过温室和现场研究，将使用 先进的分析技术。将评估研究期间土壤性质、湿度和温度对生物固体磷转化的影响。此外，还将研究土壤和根际中生物固体磷的转化、其生物利用度和在土壤中的迁移性。最后，将量化施用生物固体磷在土壤中的残留效应。