A cross-disciplinary soil-proteomics and modelling approach for predicting switches between hydrophilic and hydrophobic soil surface responses

一种跨学科的土壤蛋白质组学和建模方法，用于预测亲水性和疏水性土壤表面响应之间的切换

• 批准号: NE/K004638/1
• 负责人: Geertje Van Keulen
• 金额: $ 62.36万
• 依托单位: Swansea University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FK004638%2F1
• 关键词: cross; disciplinary; soil; proteomics; modelling

A strange property of many soils is that they do not readily wet on contact with rain, which has many implications for soil management. Although these soils may not be especially hydrophobic, wetting is slower than would be inferred from the sizes of their pores. This property is usually defined as sub-critical water repellency. Where water repellency is high (critical repellency), it causes ponding of water at soil surfaces. Water repellency affects the routes through which water and dissolved or suspended chemicals drain through the soil profile, leading to preferential surface run-off, infiltration paths resulting in serious erosion events, and flooding. Soil water repellency may be influenced by both natural and man-made events. It is known that cycles of heating and drying (amongst many other factors) may produce quite dramatic changes in this soil property. Soil water repellency results from interactions between microbial activity and physico-chemical structure, but their complexity is such that at present they are only understood on an empirical and anecdotal basis. The purpose of this project is to develop a theoretical basis to understand soil water repellency and to predict some of its consequences. The practical implications of such an understanding are profound and widespread, since they may guide land management practice and flood prevention. The three soils selected for study will be; (i) Malvern Hill clay loam, found in a previous study to exhibit extreme hydrophobicity under moderately moist summer conditions and also following air-drying in the laboratory, (ii) Gower silt loam, used in our NERC-funded proof-of-concept proteomics study and found to display up to medium levels of hydrophobicity, and (iii) Rothamsted Research Park Grass plot 3 silt loam, presently the subject of the large-scale soil metagenomic sequencing project 'Terragenome', and subcritically hydrophobic. Soil water content will be adjusted to (i) just above and (ii) just below the Critical Soil-water Content, i.e. the content at which there is a transition between hydrophobic and hydrophilic behaviour. Further perturbations will include further drying at different temperatures to water contents simulating soil conditions that may be experienced during extreme drought periods, which are likely to cause further increases in hydrophobicity.Information relating to water repellency will be obtained by the examination of soil properties at various scales of size (from nanometres to centimetres). We will establish the role of proteins in the development of water repellency using metaproteomics and specific hydrophobic protein isolation approaches. Atomic force microscopy (AFM), only recently applied to soil particles, will be used to examine their surface geography, hardness, stickiness and water repellency at this small scale. This technique combined with laser scanning microscopic techniques will be used to examine the water repellency of soil microbial proteins labelled with fluorescent dyes. Water repellency at two coarser scales will be examined using a water contact angle technique and penetration times using very small drops of water. These estimates of water repellency and soil particle properties will be incorporated into a detailed computer model of soil structure, which will be used to predict the consequences of water repellency at the decimeter scale in soil, and will be compared with laboratory measurements of the wettability of cores of a few centimeters in diameter. When the model is calibrated and validated, we will be able to use it, together with the experimental data, to predict how the perturbations change wettability. These effects will be incorporated into an existing climate model used by the Met Office, called JULES, so that predictions can be made about the likely effect of climate change. Then we will be able to suggest ways to manage UK and other soils to minimize run-off, erosion and flood risk.

许多土壤的一个奇怪特性是它们在接触雨水时不易湿润，这对土壤管理有很多影响。尽管这些土壤可能不是特别疏水，但润湿速度比根据其孔隙大小推断的要慢。该特性通常被定义为亚临界防水性。当防水性较高（临界防水性）时，会导致土壤表面积水。防水性会影响水和溶解或悬浮的化学物质通过土壤剖面排出的路线，导致优先地表径流、渗透路径，从而导致严重的侵蚀事件和洪水。土壤拒水性可能受到自然和人为事件的影响。众所周知，加热和干燥的循环（以及许多其他因素）可能会对这种土壤特性产生相当显着的变化。土壤拒水性是微生物活动和物理化学结构之间相互作用的结果，但其复杂性使得目前它们仅在经验和轶事的基础上得到理解。该项目的目的是为理解土壤拒水性并预测其一些后果奠定理论基础。这种理解的实际意义是深远而广泛的，因为它们可以指导土地管理实践和防洪。选择用于研究的三种土壤是： (i) Malvern Hill 粘壤土，在之前的研究中发现，在适度潮湿的夏季条件下以及在实验室风干后表现出极端疏水性，(ii) Gower 淤泥壤土，用于我们 NERC 资助的概念验证蛋白质组学研究，并发现显示出中等水平的疏水性，以及 (iii) Rothamsted Research Park Grass 地块 3 淤泥壤土，目前是大规模土壤的主题 宏基因组测序项目“Terragenome”，亚临界疏水性。土壤含水量将调整至 (i) 略高于和 (ii) 略低于临界土壤含水量，即疏水性和亲水性行为之间发生转变的含量。进一步的扰动将包括在不同温度下进一步干燥，以模拟极端干旱期间可能经历的土壤条件，这可能会导致疏水性进一步增加。通过检查各种尺寸（从纳米到厘米）的土壤特性，可以获得与防水性相关的信息。我们将使用宏蛋白质组学和特定的疏水性蛋白质分离方法来确定蛋白质在防水性发展中的作用。原子力显微镜（AFM）最近才应用于土壤颗粒，将用于在小范围内检查其表面形态、硬度、粘性和防水性。该技术与激光扫描显微技术相结合，将用于检查荧光染料标记的土壤微生物蛋白的防水性。将使用水接触角技术和使用非常小的水滴的渗透时间来检查两个较粗尺度的防水性。这些对防水性和土壤颗粒特性的估计将被纳入土壤结构的详细计算机模型中，该模型将用于预测土壤中分米尺度的防水性后果，并将与直径几厘米的核心润湿性的实验室测量结果进行比较。当模型经过校准和验证后，我们将能够使用它和实验数据来预测扰动如何改变润湿性。这些影响将被纳入英国气象局使用的名为 JULES 的现有气候模型中，以便可以预测气候变化可能产生的影响。然后我们将能够提出管理英国和其他土壤的方法，以尽量减少径流、侵蚀和洪水风险。

项目成果

Organic matter identifies the nano-mechanical properties of native soil aggregates.

• DOI: 10.1039/c7nr07070e
• 发表时间: 2018-01
• 期刊: Nanoscale
• 影响因子: 6.7
• 作者: S. Andrea Gazze;I. Hallin;Gerry A. Quinn;Edward G. Dudley;G. Matthews;Paul Rees;G. V. Keulen;Stefan H. Doerr;Lewis Francis

An integrated, cross-disciplinary study of soil hydrophobicity at atomic, molecular, core and landscape scales

在原子、分子、核心和景观尺度上对土壤疏水性进行综合、跨学科研究

• 发表时间: 2017
• 作者: Matthews G.P.

Atomic Force Microscopy for Soil Analysis

用于土壤分析的原子力显微镜

• 发表时间: 2016
• 作者: Gazze A

Improved Interpretation of Mercury Intrusion and Soil Water Retention Percolation Characteristics by Inverse Modelling and Void Cluster Analysis

• DOI: 10.1007/s11242-018-1087-1
• 发表时间: 2018
• 期刊: Transport in Porous Media
• 影响因子: 2.7
• 作者: G. Peter Matthews;C. L. Levy;G. Laudone;Katie L. Jones;Cathy Ridgway;I. Hallin;S. Andrea Gazze;L. Francis;W. Richard Whalley;J. Schoelkopf;P. Gane

The Metaproteome of "Park Grass" soil - a reference for EU soil science

“公园草”土壤的元蛋白质组——欧盟土壤科学的参考

• 发表时间: 2016
• 作者: Quinn G