Understanding soil quality and resilience: effects of perturbations and natural variations on nitrous oxide emission water retention and structure

了解土壤质量和恢复力：扰动和自然变化对一氧化二氮排放、保水和结构的影响

• 批准号: BB/E00296X/2
• 负责人: Tom Misselbrook
• 金额: $ 15.59万
• 依托单位: Rothamsted Research
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FE00296X%2F2
• 关键词: Understanding; soil; quality; resilience; effects

This project concerns the quality of agricultural soil. Roots need water, dissolved nutrients and oxygen, and good quality soil can transport all of these. Good soil is important for sustainable agriculture / specifically the production of grass or crops without damage to the soil or surrounding environment. The structure of soil can be damaged by compaction caused by tractor wheels or tillage. Also, if nitrate-containing soil becomes waterlogged, it exudes nitrous oxide (laughing gas). Nitrous oxide is a potent greenhouse gas causing global warming, and also adds to the destruction of the stratospheric ozone layer. If a soil is resilient, then even if it does become compacted or water-logged, it can recover. The aim of this project is to learn more about the structure and processes within soil, so that we can promote soil quality and resilience, and minimise emission of nitrous oxide. We intend to use four new, or newly improved, experimental methods, based at different research centres across the UK. These are X-ray computed tomography (similar to the CAT-scans used in hospitals), a device for measuring the water-holding ability of soil when it is being drained by gravity only, an apparatus capable of monitoring the nitrous oxide emitted from twelve laboratory samples, and a 'lysimeter' which measures the precise way nitrate is distributed and leashes through the soil under simulated rainfall. Soil is a very complicated material, and up until now studies have mostly correlated their properties without completely understanding them. To move beyond that, we enlist the help of a computer model called 'Pore-Cor' which simulates the porous structure of soil. We intend to make the model even more advanced by introducing arrays of closely packed smaller pores within the larger structure, as occur in real soil. Not only does the computer program correlate all the different properties, it also displays its results in a Virtual Reality environment / so we can climb inside the soil and see what is going on. The model will allow us to understand the geometric arrangements of the smaller pores relative to the larger, the pore environments in which the nitrous oxide is generated and vented, how nitrate distributes through the soil to feed the nitrous oxide-inducing bacteria, and how compaction and saturation affect the processes occurring. The model will also drive the experimentation forward because of its need for accurate data, and enable predictions to be made for nitrous oxide emission under other conditions and in varying soil systems. The emission of nitrous oxide is affected by other factors which will not be measured or modelled, for example temperature and wind speed. It also varies according to soil management / in particular the amount of fertiliser added, tillage, and the grazing or cropping regime. However, underlying all these effects are the fundamental structures and processes, and better understanding and prediction of these will help inform policy on land management to achieve optimum soil quality and resilience, and minimum nitrous oxide emission.

该项目涉及农业土壤的质量。根需要水、溶解的养分和氧气，优质的土壤可以输送所有这些。良好的土壤对于可持续农业/特别是在不损害土壤或周围环境的情况下生产草或农作物非常重要。拖拉机车轮或耕作造成的压实可能会破坏土壤结构。此外，如果含硝酸盐的土壤被淹，就会散发出一氧化二氮（笑气）。一氧化二氮是一种强效温室气体，会导致全球变暖，还会加剧平流层臭氧层的破坏。如果土壤具有弹性，那么即使它变得板结或浸水，它也可以恢复。该项目的目的是更多地了解土壤内部的结构和过程，以便我们能够提高土壤质量和恢复能力，并最大限度地减少一氧化二氮的排放。我们打算使用基于英国不同研究中心的四种新的或新改进的实验方法。这些是 X 射线计算机断层扫描（类似于医院使用的 CAT 扫描），一种用于测量仅通过重力排水时土壤持水能力的设备，一种能够监测十二个管道中排放的一氧化二氮的装置。实验室样本和“蒸渗仪”，用于测量模拟降雨下硝酸盐在土壤中的分布和渗透方式。土壤是一种非常复杂的材料，到目前为止，研究大多将它们的特性关联起来，但没有完全理解它们。为了超越这一点，我们寻求一种名为“Pore-Cor”的计算机模型的帮助，该模型模拟土壤的多孔结构。我们打算通过在较大的结构中引入紧密堆积的较小孔隙阵列来使该模型更加先进，就像真实土壤中的情况一样。计算机程序不仅将所有不同的属性关联起来，还在虚拟现实环境中显示其结果/这样我们就可以爬到土壤里看看发生了什么。该模型将使我们能够了解较小孔隙相对于较大孔隙的几何排列、一氧化二氮产生和排出的孔隙环境、硝酸盐如何在土壤中分布以喂养一氧化二氮诱导细菌，以及如何压实和饱和度影响发生的过程。由于需要准确的数据，该模型还将推动实验向前发展，并能够预测其他条件下和不同土壤系统中的一氧化二氮排放量。一氧化二氮的排放受到其他无法测量或建模的因素的影响，例如温度和风速。它还根据土壤管理/特别是施肥量、耕作以及放牧或耕作制度而变化。然而，所有这些影响的背后是基本结构和过程，更好地理解和预测这些影响将有助于为土地管理政策提供信息，以实现最佳的土壤质量和恢复力，以及最低的一氧化二氮排放。

项目成果

Effect of soil saturation on denitrification in a grassland soil

土壤饱和度对草地土壤反硝化作用的影响

• DOI: http://dx.10.5194/bg-2016-556
• 发表时间: 2017
• 作者: Cardenas L

A model to predict the effects of soil structure on denitrification and N2O emission

预测土壤结构对反硝化和 N2O 排放影响的模型

• DOI: http://dx.10.1016/j.jhydrol.2011.08.026
• 发表时间: 2011
• 期刊: Journal of Hydrology
• 影响因子: 6.4
• 作者: Laudone G

Isotope fractionation factors controlling isotopocule signatures of soil-emitted N2O produced by denitrification processes of various rates.

同位素分馏因子控制不同速率反硝化过程产生的土壤排放 N2O 的同位素特征。

• DOI: http://dx.10.1002/rcm.7102
• 发表时间: 2015
• 期刊: RCM
• 作者: Lewicka

Effect of soil saturation on denitrification in a grassland soil

土壤饱和度对草地土壤反硝化作用的影响

• DOI: http://dx.10.5194/bg-14-4691-2017
• 发表时间: 2017
• 期刊: Biogeosciences
• 影响因子: 4.9
• 作者: Cardenas L