•Soil mechanical and hydraulic properties were measured on soil with controlled traffic.•A framework with 4 phases (initial, intermediary, transitional, and near-stabilized) conditions was ...proposed.•Final stage of lowest entropy after 14 years of no-tillage is near steady-state, but still in “loosening” process.•Soil capacity and intensity properties should be measured to fully assess soil system behavior over time.
Recent studies have shown harmful effects of soil compaction in no-tillage system (NTS), but there are indications that soil structure improves with time of NTS adoption. We formulated the hypothesis that topsoils of NTS initially have worse soil physical conditions than those under conventional systems, but these conditions gradually improve with time also down to deeper depth, even when the soil is wheeled by farm machinery. Our objective was to evaluate the effect of a long-term no-tillage system and machine traffic on soil mechanical and hydraulic properties. The treatments and soil conditions consisted of five periods since the last conventional tillage (or age of NTS) in a Hapludox: 0.2, 1.5, 3.5, 5 and 14 years, with and without traffic; named recent tillage, and initial, intermediate, transition and stabilized NTS phases. Soil samples were collected from soil layers 0–7, 7–14 and 14–21cm depth to determine soil porosity, precompression stress, compressibility coefficient, saturated hydraulic conductivity, air permeability, water retention curve, bulk density and organic carbon. Conventional tillage of soil previously under no-tillage significantly affected soil capacity properties, resulting in high macroporosity and deformation susceptibility, low bulk density and precompression stress. Intensity properties were affected initially by an increased soil pore obstruction, negatively affecting air permeability and saturated hydraulic conductivity, from 0 to 21cm soil depth. However, after five years of no-tillage there was an increase in microporosity and, although small, in soil organic carbon, especially in the 0–7cm soil layer; thus, soil water retention and soil intensity properties (like soil water and air permeability) were also improved, regardless of farm machinery traffic. Over time, soil reconsolidation occurred, which resulted in reduction of the compressibility coefficient and degree of compactness, mainly in the upper layers (0–7 and 7–14cm). However, in the deepest layer with the least disturbance, the degree-of-compactness and bulk density increased. The evolution of physical properties and processes (from recent tillage to stabilized NTS phase) for no-tilled soil is proposed for controlled and uncontrolled traffic systems as a framework based on field data for capacity and intensity soil properties. The process of creating aggregates is represented, at first, by an increased number of contact points before they are re-loosened and strengthened at the same time by a rearrangement of particles, reducing aggregate bulk density but increasing soil strength at the same time. The framework is divided into 4 phases: initial (1.5 years), intermediary (3.5 years), transitional (5 years), and stabilized (14 years) conditions.
Under‐Liquid Biofabrication
In article number 2400311, Yi Lu, Orlando J. Rojas, and co‐workers describe a biofabrication platform for 3D cellulosic architecture construction, utilizing the aerobic ...microbial activities at the oil‐water interface. This under‐liquid biofabrication technique is leveraged by its versatility to combine with arbitrary multiphasic systems, paving a robust pathway for customizable and functionalizable material developments with relevance in biomedicine, soft robotics and bioremediation.
The application of surface treatments in concrete has been widely investigated over the past decades. Surface treatment technology has become more important in concrete structures especially in ...preventing deterioration and damage when exposed to extremely aggressive environments, and in further extending service life. This paper presents comprehensive details of four types of concrete treatments, including surface coating, hydrophobic impregnation, pore blocking surface treatment and multifunctional surface treatment. Additionally, the knowledge of their interaction mechanisms with cementitious substrate is presented and discussed. The advantages and drawbacks of each treatment as well as the influencing factors on the protective effects of surface treatments on concrete, such as air permeability, bonding strength and cracking resistance, are also discussed. Despite decades of study, the mechanisms of many newly developed surface treatments remain poorly understood. A deeper understanding of the chemical and physical reaction mechanisms is therefore essential, especially at micro-scale levels.
Soil surface is the locus of complex apportioning of mass and energy reaching the Earth. Pore system functioning of the surface soil, particularly airflow within the soil matrix, is affected by soil ...deformation. Our objective was to evaluate the effect of soil structure, moisture, and granulometry on soil aeration properties of three Oxisols and one Ultisol managed under no-tillage. Undisturbed samples (572), collected from loose (0.00–0.075m) and compact (0.075–0.15m) soil layers, were capillary saturated for 24h and equilibrated to nine water tensions, from 1 to 500kPa, to determine capacity (bulk density, volumetric moisture, air-filled porosity, and degree-of-compactness) and intensity (air conductivity and permeability, blocked porosity, and pore continuity) soil physical properties related to aeration; whereas disturbed soil samples were used for soil granulometry analysis. Soil granulometry, moisture, and structure (soil compaction) affect aeration capacity and intensity properties. Regardless of soil wetness, soil compaction reduces air-filled porosity, pore continuity, and air permeability. As soil moisture decreases, air permeability increases because of greater amount and continuity of soil pores available for air flow, and this increase in permeability is greatest in sandy-textured soil compared with clay-textured soils. Intensity properties are better descriptors of the time-variable aeration status of long-term no-tilled soils.
•Soil pore system functioning and airflow are affected by soil deformation.•We studied soil air permeability in Oxisols and Ultisol managed under no-tillage.•Soil compaction reduced primarily air-filled porosity and pore continuity.•Increased soil wetness, degree-of-compactness, and clay decrease air permeability.•Soil intensity properties are best descriptors of time-variable soil aeration status.
Air permeability is an important characteristic of windows, which significantly affects the energy consumption of a building and the quality of indoor climate in winter. Existing experimental studies ...confirm that the air permeability of windows can increase significantly when the outside temperature decreases. This phenomenon is associated with temperature deformations. Nevertheless, currently in the practice of window design the dependence of air permeability on temperature effects is not taken into account. There are methods of windows air permeability experimental determination that take into account temperature loads, but they require unique equipment and are large labor inputs. In view of this, this paper proposes a semi-empirical method for calculating the air permeability of windows with regard to temperature loads, which uses data from standard laboratory tests. This method is based on identifying the system of infiltration channels, which is formed by the window structure, with an elementary system for which the analytical solution of the infiltration equation is known. It can be used for more accurate calculations of the building's energy consumption in the cold period of time, as well as for obtaining a scientifically justified limitation of window structure deflections under the combined action of wind and temperature loads.
•An in-situ growth method evenly decorated metal–organic frameworks on nanofibers.•The superb permittivity and roughness contribute to the increased sensitivity.•The wearable capacitive sensor ...presents both high sensitivity and breathability.•The sensor’s excellent flexibility enables real-time monitoring of pulse.
Wearable electronics have emerged as versatile platforms for various biomedical applications. However, developing sensors that are both air-permeable and highly sensitive for long-term, subtle physiological signal monitoring remains a challenge. To overcome this, an innovative in-situ growth method was employed to decorate electrospun polyvinylidene fluoride (PVDF) nanofibers with a zeolitic imidazolate framework (known as ZIF-8). This approach has led to a remarkable 300% increase in sensitivity (5.94 kPa−1) compared to sensors prepared using pure PVDF nanofiber (1.42 kPa−1). This in-situ growth method effectively prevented ZIF-8 agglomeration, contributing to the desired improvement in permittivity (∼1.6), unlike blended ZIF-8/PVDF nanofiber. Furthermore, atomic force microscope and simulations were utilized to demonstrated that the nano-scale structures formed by the uniform growth of ZIF-8 significantly contribute to the enhanced sensitivity of the sensor. In addition to satisfactory air-permeability (10 mm/s) and high sensitivity, the as-prepared sensor exhibits excellent flexibility, enabling it to conform to irregular organ surfaces for real-time monitoring of pulse, respiration, and swallowing. This approach holds great promise for the development of highly sensitive and skin-friendly wearable electronics, offering significant benefits for healthcare advancement.
Optimizing tillage management is one way to reduce the risk of soil compaction due to traffic load in Northeast China. In this study, we aimed to examine the responses of precompression stress (σpc), ...compression index (Cc), pore morphology (>30 µm), air-filled porosity (εa60), air permeability at matric potential of − 60 hPa (ka60) and saturated hydraulic conductivity (Ks) to harvest traffic on soil from two contrasting tillage practices using a 10-yr old field experiment. After the crop was harvested with a combine harvester, undistributed soil cores were collected in the 0–10 and 10–20 cm layers from non-traffic and traffic zones of no-tillage (NT) and moldboard plough (MP) plots. In the non-traffic zone, the MP management showed greater total porosity (εtotal), εa60 and macroporosity (εX-ray) than the NT. There were no differences in pore connectivity, mean pore size and ka60 of the 0–10 cm layer and in Ks of the 0–20 cm layer between the two tillage practices, however, more biopores were observed under NT. Harvest traffic showed no significant effects on NT soil. In the MP plots, the εtotal, εX-ray, and pore connectivity, were decreased and pores larger than 0.15 mm were preferentially compacted. As a result of traffic, MP soil displayed lower ka60 in the 0–20 cm layer and lower εX-ray and connectivity in the 10–20 cm layer. In the NT management, the pore system had greater water and air conduction efficiencies and stable properties. Thus, compared to MP, NT can mitigate the negative effects of harvest compaction on soil in Northeast China.
•Compared with MP, NT yields lower porosity and permeability before traffic pass.•After traffic pass, NT shows more stable soil pore system and better permeability.•NT mitigates the negative effects of harvest traffic on soil pores and permeability.
•Total porosity decreased and bulk density increased after subsampling.•A slight residual effect from chiseling was detected after 5 years of NT.•CT images showed a significant tillage effect.•Gas ...transport parameters can be well predicted by CT-images.
No-tillage system (NT) has been widely adopted around the world to restore the quality of soil structure in previously tilled soils, especially in tropical and subtropical climates. Our objective was to assess the legacy of chiseling in a NT in a subtropical climate by means of gas transport and pore morphology. The experiment was conducted in a split-plot design with two factors and four replications. The main plot was divided into a part under 18 years of no-tillage (18 NT) and a part with 5 years of no-tillage after receiving 13 years of chiseling tillage down to 25 cm depth (5 NT). The subplots were soybean and maize crops. Sixteen soil samples of 567 cm3 (large cores) were sampled from the 4–12 cm depth and scanned to detect pore diameter > 120 μm. Then, small subsamples of 100 cm3 (small cores) were extracted from the large ones to detect pore diameter > 74 μm using X-ray computed tomography (CT). A range of CT-derived soil pore characteristics were quantified for both sample sizes. In the small samples, air permeability (ka) and relative gas diffusivity (Ds/Do) were determined at −60, −100, and −300 hPa matric potentials. Classical laboratory results showed no significant treatment effects on bulk density (Bd), total porosity (TP), macroporosity (εa>30), ka and Ds/Do. There was no significant treatment effect on CT-macroporosity, although 5 NT tended to be higher than 18 NT. CT images showed a significant tillage effect on CT-maximum connectivity of macropores, where for 5 NT was higher (0.75) than in 18 NT (0.65) on the large samples. Therefore, a slight residual effect from chiseling was detected after 5 years of no-tillage. TP and εa>30 decreased and Bd increased significantly after subsampling. Ds/Do and ka were significantly correlated to CT-derived pore characteristics. This suggests that CT image analysis has high capacity for predicting gas transport.
•Compaction effects on soil properties 30–90 cm were investigated for a sandy loam.•Visual evaluation of soil profiles showed detrimental impacts to >50 cm.•Laboratory measurements quantified ...detrimental effects on soil pore characteristics.•A single pass of 12 Mg loaded self-propelled machine wheel had only minor effects.•Multiple pass of 8 Mg loaded wheels with high traction had major impacts.
Traffic in agricultural fields with very high wheel loads imposes a risk of severe structural damage deep into the subsoil. However, there is a paucity of studies quantifying these effects. This study focuses on heavy traffic-induced changes in soil structure for a sandy loam soil in a temperate region. The treatments included no compaction (Control), compaction with ∼3 Mg (M3) and ∼8 Mg (M8) wheel loads with multiple (4–5) wheel passes, and compaction with a single-pass wheel load of ∼12 Mg (S12). The compaction treatments were replicated four consecutive years. Subsoil structural quality was evaluated visually by the SubVESS method, and soil pore characteristics were quantified for minimally disturbed soil cores sampled at 30, 50, 70 and 90 cm depth two years after the end of the experiment. Our results indicate that M8 significantly affected soil structural properties to >50 cm depth in terms of reduced subsoil structural quality, air-filled pore space, air permeability, gas diffusivity, pore volume and increased bulk density. Results also showed that the degree of compactness was ≥95% for M8 at 30 and 50 cm depth. Even though a pre-existing dense soil matrix was described in the studied soil, results confirmed that high wheel loads may cause significant subsoil compaction at >50 cm depth. Surprisingly, the S12 treatment did not show marked signs of decreasing structural quality at depth. Thus, our results indicate that primarily traffic applying multiple passes with high wheel loads compromises soil structure at depth. The S12 results further suggest the need to investigate the influence of factors other than wheel load and inflation pressure on the risk of subsoil compaction.
Intensive soil disturbance by conventional tillage and heavy machinery traffic for planting, cultivation, and harvesting operations are the main causes of soil compaction and degradation of soil ...physical quality in sugarcane fields. However, the adoption of conservation soil tillage practices, such as no-till and reduced tillage associated with traffic control have been proposed as a key strategy to preserve soil physical quality, enhancing water availability and air fluxes. Nevertheless, the effects of reduced tillage associated with traffic control in sugarcane fields are still not well documented. A study was carried out to quantify soil water availability and air flux indicators in two soils with contrasting textures (named Sandy Loam and Clayey soil) under conventional and reduced tillage practices associated with and without controlled machinery traffic in central-southern Brazil. Soil physical parameters such as bulk density, total porosity, air-filled porosity, air permeability, pore continuity index, and the least limiting water range (LLWR) were measured. In both soils, there was no difference between conventional and reduced tillage in bulk density, air permeability, and LLWR. However, reduced tillage with non-traffic decreased bulk density and increased macroporosity, air-filled porosity, air permeability, pore continuity, and LLWR in Sandy Loam soil. In Clayey soil, the bulk density and LLWR did not change between tillage practices, but air permeability and pore continuity index were larger under reduced tillage with non-traffic. These results highlighted that soil disturbance by conventional tillage does not improve the water availability and air permeability during the crop cycle. However, the traffic control is essential to support the adoption of reduced tillage in sugarcane fields, preserving soil water availability and air fluxes for the subsequent ratoons. Reduced tillage and traffic control are two of the most important pillars for reducing soil compaction and promoting sustainability of sugarcane production in Brazil.
•Reduced tillage system did not negatively impact the least limiting water range (LLWR) compared to conventional tillage.•Reduced and conventional tillage system sustain similar air-filled porosity and air permeability.•Reduced tillage associated with traffic control increase LLWR in Sandy loam soils.•Traffic control is essential to support the adoption of reduced tillage in sugarcane fields.
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