权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Monitoring root water uptake processes by the novel combination of magnetic resonance- and neutron imaging.

通过磁共振和中子成像的新颖组合监测根系吸水过程。

基本信息

批准号：
243975263
负责人：
Dr. Sabina Haber-Pohlmeier
金额：
--
依托单位：
Lehrstuhl für Hydromechanik und Hydrosystemmodellierung
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2013
资助国家：
德国
起止时间：
2012-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/243975263?language=en
关键词：
Monitoring root water uptake processes

项目摘要

The soil in direct vicinity of the roots, the so called rhizosphere, is heavily modified by the activity of roots, compared to bulk soil, e.g. in respect to microbiology and soil chemistry. In recent time it has turned out that the rhizosphere, though small in size, also plays a decisive role in the hydraulics controlling the water flow from bulk soil into the roots. The most promising tool for the non-invasive investigation of water dynamics, water flow and solute transport is the combination of the two imaging techniques magnetic resonance imaging (MRI) and neutron imaging (NI). Both methods are complementary: NI maps the total proton density which corresponds to total water content, and is able to detect changes and spatial patterns with high resolution. On the other side, NMR relaxation times reflect the interaction between fluid and matrix. Therefore MRI is additionally capable of classifying different water pools via their relaxation times in terms of structural water,bound water, and mobile water. In this project both methods will be combined for the first time for the detailed, three-dimensional imaging of the system root-rhizosphere-bulk soil. In order to avoid alterations of this sensitive zone by long range transport, additionally to a conventional high-field MRI device, a movable MRI system will be used that allows 3D imaging on-site at the neutron imaging facility. Investigated systems are young lupin and maize plants in fine sandy and sandy loam soils under steady state conditions, but also during desiccation - rewetting cycles.As main results we expect for the first project phase the characterization of the root, rhizosphere and surrounding bulk soil by water content (NI) and water dynamics (MRI) ending up in a classification of water fractions in the rhizosphere. After the steady state conditions in the second project phase flux processes from soil to roots are mapped by tracer tracking under stationary and rewetting cycles, respectively. The overall aim is to calculate uptake rates for different compartments and conclude on changes in conductivities.

与散装土壤相比，根附近的土壤，即所谓的根际，受到根的活动的严重影响，例如在微生物学和土壤化学方面。近年来，人们发现，根际虽然很小，但在控制水分从大块土壤流入根系的水力学中也起着决定性的作用。最有前途的工具，非侵入性调查的水动力学，水流和溶质运移是两种成像技术磁共振成像（MRI）和中子成像（NI）的组合。这两种方法是互补的：NI绘制与总含水量相对应的总质子密度图，能够以高分辨率探测变化和空间模式。另一方面，NMR弛豫时间反映了流体和基质之间的相互作用。因此，MRI还能够根据结构水、结合水和移动的水通过其弛豫时间对不同的水池进行分类。在该项目中，这两种方法将首次结合起来，对系统根-根际-土壤进行详细的三维成像。为了避免长距离运输对敏感区的影响，除了传统的高场MRI设备外，还将使用可移动的MRI系统，该系统允许在中子成像设施现场进行3D成像。调查系统是年轻的羽扇豆和玉米植物在细桑迪和桑迪壤土在稳态条件下，但也在干燥-再湿cycle.As主要结果，我们预计在第一个项目阶段的根，根际和周围的散装土壤的含水量（NI）和水动力学（MRI）的特性结束了在根际水馏分的分类。在第二个项目阶段的稳态条件后，从土壤到根系的通量过程被映射的示踪剂跟踪下的固定和再润湿周期，分别。总体目标是计算不同隔室的吸收率，并得出电导率变化的结论。