Article
Agronomy
Jose V. Gaspareto, Jocenei A. T. de Oliveira, Everton Andrade, Luiz F. Pires
Summary: Representative elementary volume (REV) is required for representative measurements of soil physical properties. The REV depends mainly on the land uses for porosity and pore connectivity. The core method showed lower REV due to the larger volume analyzed than that in the cube method. It was not possible to define a REV for degree of anisotropy. The REV obtained using the cube method was more sensitive to changes in the scale of analysis, showing an increasing trend with applied wetting and drying cycles for porosity and fractal dimension.
Article
Astronomy & Astrophysics
M. F. Salek, L. E. Beckingham
Summary: Three-dimensional X-ray computed tomography imaging is a nondestructive method for microstructural characterization, but it requires time and high-performance computing to obtain and process high-quality images. This study evaluated the effects of different imaging parameters on pore connectivity and surface area quantification in sandstone samples. The results showed that there was little variation in bulk porosity, but low resolution and projection numbers resulted in lower connected porosity. Increasing bin size, voxel size, and projection numbers led to a decrease in mineral surface area, except for samples with more clay content where an increase in projection numbers resulted in an increase in surface area.
EARTH AND SPACE SCIENCE
(2023)
Article
Engineering, Civil
Tiande Wen, Xiangsheng Chen, Longtan Shao
Summary: This study examined the macropore structure of granite residual soil during multiple wetting and drying cycles using X-ray computed tomography. The results showed that the cycles caused soil shrinkage and reduced pore connectivity, leading to an increase in isolated pores. Wetting contributed to the recovery of lost pores and connections, increasing pore space and porosity. The connected macropores played a decisive role in the soil's saturated hydraulic conductivity.
JOURNAL OF HYDROLOGY
(2022)
Article
Engineering, Manufacturing
Jacques Kruger, Anton du Plessis, Gideon van Zijl
Summary: Concrete structures produced by extrusion-based 3D printing exhibit orthotropic mechanical behavior and relative weakness in interfacial regions. The microstructure, including porosity content and distribution, plays a key role in these properties and can be visualized and quantified using X-ray computed tomography. Further research is needed to understand the effect of stress concentrations at micro-cracks or voids in 3D printed concrete on mechanical behavior.
ADDITIVE MANUFACTURING
(2021)
Article
Soil Science
Sarah Smet, Erwan Plougonven, Angelique Leonard, Aurore Degre
Summary: In order to understand soil processes such as greenhouse gas release and microbial proliferation, it is important to quantitatively assess the changes in soil pore space connectivity as the soil dries. X-ray computed microtomography (μCT) can provide direct information on this, eliminating the need for interpretation based on macroscopic measurements using capillary theory. This study presents different quantitative methods to describe the configuration of the air-filled pore space in 3D μCT images of loamy soil samples. Results show that, in general, soil samples behave as expected, with increasing connectivity and decreasing tortuosity as the matric potential becomes more negative. However, no simple correlations were found between quantitative descriptors of pore space and macroscopic soil parameters.
EUROPEAN JOURNAL OF SOIL SCIENCE
(2023)
Article
Geochemistry & Geophysics
Jinsui Wu, Min Xing, Shangxian Yin, Ciyuan Zhang, Xuexi Chen, Sihai Yi, Huiqing Lian, Dongyu Xie
Summary: The microstructure and permeability of low-permeability sandstone samples obtained from North China were studied using digital core technology. The researchers collected rock images using X-ray microcomputed tomography (mu CT) and analyzed the microstructure to calculate parameters such as porosity, connected porosity, average equivalent diameter, tortuosity, and shape factor. By introducing the shape factor into the Kozeny-Carman equation, they modified the equation to include porosity, particle diameter, tortuosity, and particle shape factor.
Article
Multidisciplinary Sciences
Joseph Avila, Javier Pagalo, Mayken Espinoza-Andaluz
Summary: This study analyzes the geometric tortuosity by considering the porosity and pore size distribution, and finds that the geometric tortuosity depends not only on porosity but also on the pore size. Experimental results show that the geometric tortuosity increases when the pore size is reduced even with the same porosity. Additionally, the size of the medium affects the pore size effects. This study proposes the A-star algorithm and the Pore Centroid method as suitable methods for estimating geometric tortuosity.
SCIENTIFIC REPORTS
(2022)
Article
Soil Science
Aurelie Bacq-Labreuil, Andrew L. Neal, John Crawford, Sacha J. Mooney, Elsy Akkari, Xiaoxian Zhang, Ian Clark, Karl Ritz
Summary: Agricultural practices can significantly influence the physical and biological properties of soil, with conversion to grassland leading to notable changes in soil structure over a period of at least a decade post-conversion. Conversion to arable land, on the other hand, did not show a significant impact on soil structural evolution.
EUROPEAN JOURNAL OF SOIL SCIENCE
(2021)
Article
Soil Science
M. P. Salazar, L. A. Lozano, R. Villarreal, A. B. Irizar, M. Barraco, N. G. Polich, C. G. Soracco
Summary: Soil physical degradation is a current problem in the Molisols of the Pampas Region under no-tillage. Cover crops have been proposed as a solution to improve soil physical quality, but their effectiveness may vary depending on soil texture and management practices.
SOIL & TILLAGE RESEARCH
(2022)
Article
Environmental Sciences
Xiaokun Hou
Summary: The soil-water characteristic curve (SWCC) is an important parameter for describing soil moisture distribution and water movement. It is controlled by the soil's pore structure. The accuracy of SWCC prediction using the mercury intrusion porosity (MIP) technique needs further validation. The study shows that MIP data accurately predicts the SWCC for intact and dry samples, but significant errors occur for compacted samples.
Review
Soil Science
D. Luke R. Wardak, Faheem N. Padia, Martine I. de Heer, Craig J. Sturrock, Sacha J. Mooney
Summary: This paper reviews 34 studies that demonstrate the influence of zero-tillage (ZT) on porosity, depending on soil texture, pore size class, and depth. ZT can also affect important transport mechanisms that impact the fate of agrochemicals in soils, although the effects on hydraulic transport are less clear.
Article
Geosciences, Multidisciplinary
Jue Peng, Xinliang Wu, Shimin Ni, Junguang Wang, Yantun Song, Chongfa Cai
Summary: The pore structure is crucial for soil aggregation and various processes within aggregates. This study examined the intra-aggregate microstructure of six weathered soils under different climates. Results showed significant differences in the microstructure among soil types, with differences in porosity, pore size distribution, and pore shape. Soil organic carbon and aluminum oxides were found to have a positive effect on the microstructure, while iron oxides had a negative effect.
Article
Construction & Building Technology
Dongya Ren, Jie Xu, Shaonan Su, Gangsheng Tian, Xu Chen, Allen Zhang, Changfa Ai
Summary: This study uses 3D X-ray computed tomography technology to analyze the digital images of three typical asphalt mixtures with different porosities, and quantitatively and statistically analyzes several pore structure parameters at a micro level. The results show that as the total pores content increases, the difference between the pore fraction and open pores fraction decreases. The porosity of porous asphalt mixtures is high, but mainly composed of interconnected pores with only a small proportion of closed pores. The coordination number determines the connectivity and thus the porosity of the asphalt mixture, and larger open pore channels lead to larger pore diameters and greater permeability.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Marchant van den Heever, Anton du Plessis, Jacques Kruger, Gideon van Zijl
Summary: Elements fabricated by extrusion-based 3D concrete printing (3DCP) exhibit anisotropic mechanical properties, and the porosity has been found to affect the elasticity and compressive strength. This research quantitatively investigates the porosity metrics of a fibre-reinforced printable concrete (FRPC) mixture and finds that 3DCP samples have higher porosity and altered void attributes. Experimental findings show that the increase in porosity is associated with a decrease in elastic modulus and compressive capacity. The porosity is influenced by factors such as loading direction, stress concentrations, and deformability of the composite configuration.
CEMENT AND CONCRETE RESEARCH
(2022)
Article
Soil Science
Huan Fang, Kailou Liu, Daming Li, Xinhua Peng, Weijian Zhang, Hu Zhou
Summary: Inorganic fertilizers have limited effects on paddy soil structure, while green manure and swine manure can improve soil pore structure and soil aggregation. The combined application of inorganic fertilizers and green manure significantly increased soil organic carbon content and pore connectivity.
SOIL & TILLAGE RESEARCH
(2021)
Article
Biotechnology & Applied Microbiology
Gregory D. Rix, Jonathan D. Todd, Andrew L. Neal, Charles A. Brearley
Summary: HPLC methods are effective for predicting phytase activity, simplifying candidate selection, and revealing diversity of phytases. Combining with 16S sequencing and bioinformatics can uncover the contribution of MINPP activity to soil phytase activity.
MICROBIAL BIOTECHNOLOGY
(2021)
Article
Microbiology
Andrew L. Neal, Timothy McLaren, Mariana Lourenco Campolino, David Hughes, Antonio Marcos Coelho, Ubiraci Gomes de Paula Lana, Eliane Aparecida Gomes, Sylvia Morais de Sousa
Summary: The study found that different phosphorus fertilizer sources did not significantly affect crop performance, but did influence the accumulation of fertilizer phosphorus into organic soil pools. Phosphatase activity was the only biological parameter influenced by phosphorus fertilization. Differences in rhizosphere microbiomes were observed due to crop type, not fertilization.
FEMS MICROBIOLOGY ECOLOGY
(2021)
Article
Engineering, Civil
Xiaoxian Zhang, Andrew L. Neal, John W. Crawford, Aurelie Bacq-Labreuil, Elsy Akkari, William Rickard
Summary: The study revealed that soil structure changed after long-term fertilization, with different alterations observed at core and aggregate scales. Fertilization had a more significant impact on the core scale than on the aggregate scale, and aggregates fertilized with farmyard manure and in woodland were more permeable. Fertilization affected porosity, permeability, and tortuosity of the soil.
JOURNAL OF HYDROLOGY
(2021)
Article
Mathematics, Interdisciplinary Applications
Miguel Angel Martin, John W. Crawford, Andrew Neal, Carlos Garcia-Gutierrez
Summary: Metagenomics provides insights into the structure and function of the human gut microbiome, showing commonalities and resilience across host populations. The non-random clustering of taxa suggests functional networks in the microbiome community. Researchers seek models to understand the underlying structure and properties of microbiomes.
FRACTALS-COMPLEX GEOMETRY PATTERNS AND SCALING IN NATURE AND SOCIETY
(2021)
Article
Microbiology
Danteswari Chalasani, Anirban Basu, Sarma V. S. R. N. Pullabhotla, Beatriz Jorrin, Andrew L. Neal, Philip S. Poole, Appa Rao Podile, Andrzej Tkacz
Summary: Pigeon pea, a primary protein source for over a billion people in developing countries, forms symbiosis with N-2-fixing bacteria, particularly Rhizobium spp. The bacterial community associated with pigeon pea is significantly influenced by plant roots location, developmental stage, and soil type, with Proteobacteria being the dominant group. Native symbiont Bradyrhizobium spp. struggles to effectively colonize pigeon pea roots, leading to poor nodulation in Indian soils. This emphasizes the importance of symbiont competitiveness in agricultural soils for improving pigeon pea yield and reducing food poverty.
Article
Microbiology
Andrew L. Neal, David Hughes, Ian M. Clark, Janet K. Jansson, Penny R. Hirsch
Summary: Soil management practices, particularly in agriculture, affect soil microbiomes and their community structures and functional states. Understanding how soil microbiomes respond to combined stresses is crucial for predicting system performance under different land use scenarios and identifying environmentally friendly management practices.
Article
Environmental Sciences
Erping Cui, Xiangyang Fan, Chao Hu, Andrew L. Neal, Bingjian Cui, Chuncheng Liu, Feng Gao
Summary: This study found that regulating N in NPK fertilizer can effectively reduce the risk of ARGs associated with reclaimed water irrigation in soil, with N fertilization having the strongest impact on bacterial communities in soil.
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
(2022)
Article
Soil Science
Feng Wang, Xiaoxian Zhang, Andrew L. Neal, John W. Crawford, Sacha J. Mooney, Aurelie Bacq-Labreuil
Summary: Through studying soil samples archived from a reversion experiment initiated in 2008 at Rothamsted Research in the UK, it was found that the intra-aggregate reconfiguration following management changes is a slow process, and the ability of pore space to transport substrates is more important than the habitat they provide in SOC stabilization.
SOIL & TILLAGE RESEARCH
(2022)
Article
Soil Science
Jolanda E. Reusser, Federica Tamburini, Andrew L. Neal, Rene Verel, Emmanuel Frossard
Summary: This study elucidates the chemical nature of increasing molecular size organic phosphorus (Porg) in soil extracts using gel-filtration size exclusion chromatography (SEC) and solution 31P nuclear magnetic resonance (NMR) spectroscopy. The results show that organic P is present across the entire molecular size range and comprises multiple components of varying NMR peak line width. Additionally, the stabilisation of inositol hexakisphosphates (IP6) in soils is associated with the organic phase.
Article
Engineering, Environmental
Yuan Liu, Andrew L. Neal, Xiaoxian Zhang, Haiyan Fan, Honglu Liu, Zhongyang Li
Summary: The impact of reclaimed wastewater irrigation on the spread of antibiotic resistance genes in soil is influenced by various biotic and abiotic factors, with cropping system having a greater effect on the profile of ISs and resistance genes than irrigation. Most ARGs co-occurred with metal and biocide resistance genes through efflux pumps, emphasizing the importance of understanding and enhancing crop management for mitigating ARG dissemination in RW-irrigated soils.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Environmental Sciences
Silvia Garaycochea, Nora Adriana Altier, Carolina Leoni, Andrew L. Neal, Hector Romero
Summary: Grassland biomes provide important ecosystem services through nutrient cycling, with organic phosphorus (Po) being a significant component of soil phosphorus. This study analyzed soil metagenomes from different grassland biomes worldwide to investigate the distribution and abundance of key P enzymes and their relationship with environmental factors. The results showed that alkaline phosphatase phoD was the most abundant P enzyme gene, followed by acid phosphatases Nsap-A and Nsap-C. pH, T-max, SOC, and soil moisture were found to be associated with the abundance and diversity of all studied genes, and the presence of certain genes correlated with specific soil properties.
ENVIRONMENTAL MICROBIOLOGY REPORTS
(2023)
Article
Food Science & Technology
Andrew L. Neal, Harry A. Barrat, Aurelie Bacq-Lebreuil, Yuwei Qin, Xiaoxian Zhang, Taro Takahashi, Valentina Rubio, David Hughes, Ian M. Clark, Laura M. Cardenas, Laura-Jayne Gardiner, Ritesh Krishna, Margaret L. Glendining, Karl Ritz, Sacha J. Mooney, John W. Crawford
Summary: Achieving food security requires resilient agricultural systems with improved nutrient-use efficiency, optimized water and nutrient storage in soils, and reduced gaseous emissions. Our study demonstrates how the influence of organic matter on nitrogen transformations in arable soils can be deciphered by integrating metagenomic data with soil structural parameters.
Article
Microbiology
Alexander D. Williams, Emily Rousham, Andrew L. Neal, Mohammed Badrul Amin, Jon L. Hobman, Dov Stekel, Mohammad Aminul Islam
Summary: Through the use of DNA sequencing, our study shows that there is no significant difference in the antibiotic resistance genes found in stool samples taken from individuals with high exposure to poultry routinely fed antibiotics and those without such exposure. This finding is significant as it suggests limited transmission of antibiotic resistance genes between poultry and humans in these circumstances. However, our research also demonstrates that commercially reared poultry are more likely to possess resistance genes to antibiotics commonly administered on medium-sized farms. Additionally, our study highlights the under-explored potential of wastewater as a source of various antibiotic resistance genes, some of which are clinically relevant.
MICROBIOLOGY SPECTRUM
(2023)
Article
Multidisciplinary Sciences
Xiaoxian Zhang, Peter A. Whalley, Andrew S. Gregory, W. Richard Whalley, Kevin Coleman, Andrew L. Neal, Sacha J. Mooney, Kenichi Soga, Tissa H. Illangasekare
Summary: Biogeochemical reactions in soil pore space play a crucial role in the gaseous emissions measured on a macroscopic scale, but their quantification is challenging due to the complexity and heterogeneity of soils. In this study, a volumetric-average method is developed to calculate aerobic respiration rates using a microscopic representation of soil structure. The results show that the model accurately reproduces the variations in carbon dioxide emissions under different soil water content and temperature gradients, suggesting that it captures the key microscopic processes governing soil respiration. The study highlights the importance of incorporating oxygen dissolution and diffusion in water associated with soil pore space in soil organic carbon models, in addition to thermal microbial adaptation, substrate heterogeneity, microbial turnover, and carbon use efficiency.
JOURNAL OF THE ROYAL SOCIETY INTERFACE
(2022)
Article
Developmental Biology
M. Jordana Rivero, Nicolas Lopez-Villalobos, Alex Evans, Alexandre Berndt, Andrew Cartmill, Andrew L. Neal, Ann McLaren, Anne Farruggia, Catherine Mignolet, Dave Chadwick, David Styles, Davy McCracken, Dennis Busch, Graeme B. Martin, Hannah Fleming, Helen Sheridan, James Gibbons, Lutz Merbold, Mark Eisler, Nicola Lambe, Pablo Rovira, Paul Harris, Paul Murphy, Philip E. Vercoe, Prysor Williams, Rui Machado, Taro Takahashi, Thomas Puech, Tommy Boland, Walter Ayala, Michael R. F. Lee
Summary: Research-led animal and plant breeding, as well as feeding strategies, are essential for optimizing ruminant systems to address the challenges of climate change and limited land resources.
REPRODUCTION FERTILITY AND DEVELOPMENT
(2021)
