Soil & Tillage Research最新文献

{"title":"Multiyear crop residue cover mapping using narrow-band vs. broad-band shortwave infrared satellite imagery","authors":"Brian T. Lamb ,&nbsp;W. Dean Hively ,&nbsp;Jyoti Jennewein ,&nbsp;Alison Thieme ,&nbsp;Alexander M. Soroka ,&nbsp;Leticia Santos ,&nbsp;Daniela Jones ,&nbsp;Steven Mirsky","doi":"10.1016/j.still.2025.106524","DOIUrl":"10.1016/j.still.2025.106524","url":null,"abstract":"<div><div>Crop residue serves an important role in agricultural systems as high levels of fractional crop residue cover (<em>f</em>_R) can reduce erosion, preserve soil moisture, and build soil organic carbon. However, the ability to accurately quantify <em>f</em>_R at scale has been limited. In this study we produced annual maps of <em>f</em>_R for farmland in Maryland, USA using WorldView-3 (WV3) imagery paired with on-farm photographs (<em>n</em> = 895) classified to <em>f</em>_R using SamplePoint software. Univariate linear regressions were used to compare photograph <em>f</em>_R to WV3 crop residue indices including: 1) Shortwave Infrared Normalized Difference Residue Index (SINDRI), 2) Shortwave Infrared Difference Residue Index (SIDRI), 3) Normalized Difference Tillage Index (NDTI), and 4) Shortwave Infrared Angle Index (SWIRA). SINDRI and SIDRI are based on narrow bands capable of measuring lignocellulose absorption features. NDTI and SWIRA are based on Landsat-comparable broad bands. Our findings demonstrated that SINDRI outperformed other indices in <em>f</em>_R estimation in terms of coefficient of determination (<em>R</em>² = 0.869) and root mean square error (RMSE = 0.111), when <em>R</em>² and RMSE were averaged across six individual years. For a univariate analysis combining five years of high-quality WV3 imagery, SINDRI again exhibited the highest <em>f</em>_R estimation performance (<em>R</em>² = 0.795; RMSE = 0.141), suggesting that SINDRI can map <em>f</em>_R accurately with a singular relationship, potentially reducing the need for labor-intensive ground data collection. For broad-band indices, a multiple linear regression analysis that included a Water Index (WI) and Normalized Difference Vegetation Index (NDVI) as additional predictors increased the accuracy of <em>f</em>_R estimation significantly, particularly for SWIRA (<em>R</em>² = 0.767; RMSE = 0.144), but also NDTI (<em>R</em>² = 0.654; RMSE = 0.174). Our findings suggest that while indices computed from narrow-band imagery are most accurate for <em>f</em>_R estimation, SWIRA has the potential to improve <em>f</em>_R estimation compared to NDTI, especially when used in conjunction with WI and NDVI. An index suite of SWIRA, WI, and NDVI can be computed with Landsat 4–9 imagery, providing a more accurate record of global <em>f</em>_R dating back to 1982.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"251 ","pages":"Article 106524"},"PeriodicalIF":6.1,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil physical quality using DRES and VESS visual assessment approaches and physical properties","authors":"Ana Clara Barbosa de Souza ,&nbsp;Tairone Paiva Leão ,&nbsp;Cícero Célio de Figueiredo ,&nbsp;Marcos Aurélio Carolino de Sá","doi":"10.1016/j.still.2025.106558","DOIUrl":"10.1016/j.still.2025.106558","url":null,"abstract":"<div><div>Soil structure evaluation is one of the main tools for diagnosing changes in soil physical quality under contrasting land-use systems. Visual assessment methods have been proposed as a low cost and practical alternative to traditional methods for evaluating soil structural quality. The Rapid Diagnosis of Soil Structure (DRES) is one of the most recent visual methods proposed for assessing the structural condition of tropical soils. It is supposed to improve on other methods by setting a lower soil aggregates diameter limit for soils with good structural quality. There are few publications which assess its performance and correspondence to other soil physical properties. Thus, this study evaluated the structural quality of an Oxisol (Typic Haplustox) under pasture system (PS), silage corn under direct seeding (DS), banana orchard (BA) and native vegetation Cerrado (CN) using the DRES methodology. In addition, we correlated the scores of the visual analysis with the soil physical properties bulk density (BD), total porosity (TP), soil penetration resistance (SPR), soil penetration resistance corrected to the field capacity (SPR_FC), weighted average diameter of aggregates (WAD), soil organic matter (OM) and parameters of the water retention curve (WRC). A comparison was also made between DRES and the Visual Evaluation of Soil Structure (VESS) methodology. The soil under PS and DS showed the lowest scores for the DRES, and consequently the worst structural soil quality condition. The physical properties BD, TP, SPR, microporosity (MICRO) and macroporosity (MACRO) showed significant correlation with the visual analysis scores obtained using DRES and VESS. In general, DRES distinguished the soil structural quality under different land-use systems and can be considered a promising semi-quantitative method in diagnosing soil structural quality. However, even though DRES and VESS scored similarly in this study, there are possible critical incompatibilities between the two systems regarding diameter of aggregates that need to be addressed in further studies.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"251 ","pages":"Article 106558"},"PeriodicalIF":6.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143737984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sustainable no–tillage practices with a disc type novel residue cleaning mechanism: Design, development and field evaluation","authors":"Manish Kumar ,&nbsp;Kamendra ,&nbsp;H.S. Pandey ,&nbsp;K.P. Singh ,&nbsp;Chetna Verma ,&nbsp;Satish Kumar Singh ,&nbsp;Dushyant Singh","doi":"10.1016/j.still.2025.106560","DOIUrl":"10.1016/j.still.2025.106560","url":null,"abstract":"<div><div>Crop residue management in no–tillage under conservation agriculture is crucial for maintaining soil health and optimizing crop yields. This study presents a residue cleaning mechanism specially designed for no–tillage sowing to overcome challenges posed by crop residues left by combine harvesters. This research involved design, development and field–evaluation of a residue cleaning unit attached to a seed–cum–fertilizer drill equipped with a broad–spacing toolbar. The initial trials optimized operational parameters in a test soil bin, showing maximum residue removal efficiency at 45° disc angle and 20° tilt angle. Following these trials, a tractor drawn six units of residue cleaning discs, each with 12 teeth and a diameter of 350 mm were fabricated along with an inverted T–type furrow opener. The developed prototype of six-row seed–cum–fertilizer drill with a residue cleaning mechanism (T1) was evaluated for the wheat–green gram–maize cropping system and compared with the ten–row Happy Seeder (T2). The results showed that the improvement in grain yield for green gram (6.05 %) was significantly higher for T1 compared to T2. However, the improvements in grain yield for wheat (4.43 %) and maize (0.86 %) was not statistically significant (p &lt; 0.05), resulting in higher net incomes for T1. For each cropping system, the energy analysis showed that, T1 (27.47 MJ/kg) required slightly less specific energy than T2 (28.34 MJ/kg). However, T1 had slightly higher total carbon emissions (10970.89 kg CO2eq/ha) compared to T2 (10638.17 kg CO2eq/ha). The benefit–cost ratio was lower for T1 (2.08) compared to T2 (2.16), but increasing the number of rows in the T1 treatment could enhance field capacity, potentially reducing carbon emissions and improving economic returns.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"251 ","pages":"Article 106560"},"PeriodicalIF":6.1,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143737985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linking microbial metabolism and ecological strategies to soil carbon cycle function in agroecosystems","authors":"Xianwen Long ,&nbsp;Jiangnan Li ,&nbsp;Xionghui Liao ,&nbsp;Wei Zhang ,&nbsp;Kelin Wang ,&nbsp;Jie Zhao","doi":"10.1016/j.still.2025.106562","DOIUrl":"10.1016/j.still.2025.106562","url":null,"abstract":"<div><div>Revealing regional-scale differences in microbial community structure and metabolic strategies across different land use types and soil types and how these differences relate to soil carbon (C) cycling function is crucial for understanding the mechanisms of soil organic carbon (SOC) sequestration in agroecosystems. However, our understanding of these knowledge still remains unclear. Here, we employed metagenomic methods to explore differences in microbial community structure, functional potential, and ecological strategies in calcareous soil and red soil, as well as the relationships among these factors and SOC stocks. The results showed that the bacterial absolute abundance and diversity were higher and the fungal absolute abundance and diversity were lower in calcareous soil than in red soil. This may be attributed to stochastic processes dominated the assembly of bacterial and fungal communities in calcareous soil and red soil, respectively. This in turn was closely related to soil pH and Ca^2 + content. Linear discriminant analysis showed that genes related to microbial growth and reproduction (e.g., amino acid biosynthesis, central carbon metabolism, and membrane transport) were enriched in calcareous soil. While genes related to stress tolerance (e.g., bacterial chemotaxis, DNA damage repair, biofilm formation) were enriched in red soil. The great difference in soil properties between calcareous soil and red soil may be the cause of this result. Compared with red soil, the higher soil pH, SOC, and calcium and magnesium content in calcareous soil increased the bacterial absolute abundance and diversity, thus increasing the SOC sequestration potential of microorganisms, but also increased the decomposition of organic carbon by fungi, thus increasing the SOC loss potential. However, the bacterial absolute abundance and diversity were much higher than that of fungi. Therefore, soil carbon sequestration potential was still greater than its loss potential in karst agroecosystems. Agricultural disturbance intensity may be the main factor affecting these relationships. Overall, these findings advance our understanding of how soil microbial metabolic processes are related to SOC sequestration.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"251 ","pages":"Article 106562"},"PeriodicalIF":6.1,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143737983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of concentrated flow and shallow water table on pesticides trapping efficiency of vegetative filter strips – A case study of Northeast China","authors":"Liming Yan ,&nbsp;Yang Ou ,&nbsp;Yuanyuan Sui ,&nbsp;Huiping Liu ,&nbsp;Yang Deng ,&nbsp;Qi Cui ,&nbsp;Minglian Shang","doi":"10.1016/j.still.2025.106557","DOIUrl":"10.1016/j.still.2025.106557","url":null,"abstract":"<div><div>The Northeast Black Soil Region is a key grain production area in China, facing significant pesticide runoff risks due to extensive agricultural activity. Vegetative filter strips (VFS) are crucial for reducing diffuse pollution, but their effectiveness is compromised by concentrated flow (CF) and shallow water table (SWT) conditions. Quantitatively assessing the negtive effects of these hydrological processes on VFS pesticide removal performance has thus become an urgent issue. This study combined field monitoring with VFSMOD-W simulation to quantify the impacts of CF and SWT on VFS pesticide removal performance. Results show that under typical meteorological conditions in the Black Soil Region, the performance decline of VFS accelerates when CFR exceeds 30 %, and becomes significantly compromised when CFR reaches 60 %. However, SWT effects are less severe, with significant performance declines observed only when it is below 0.5 m. When SWT rises to 0.2 m, outflow reaches 2.2 times the inflow, pesticide removal drops by 55 %, while sediment removal remains stable. When both CF and SWT reach critical thresholds, the decline in pesticide removal is not additive. Pearson correlation analysis and redundancy analysis (RDA) further highlighted that impacting factors explain 86.8 % of VFS performance variability, with CF, SWT, VFS length in the direction of flow (VL), soil vertical saturated hydraulic conductivity (VKS), and rainfall intensity (T) identified as primary influencing factors. To optimize VFS performance, identifying CF pathways and extending VFS length are essential. Additionally, deep plowing to break plow pans and using mixed plant species with robust root systems for riparian restoration are recommended strategies for SWT. This integrated approach offers insights for enhancing VFS efficiency in mitigating agricultural pollution in the Black Soil Region and similar ecosystems globally.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"251 ","pages":"Article 106557"},"PeriodicalIF":6.1,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143735201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Soil structure development in a five-year chronosequence of maize cropping on two contrasting soil textures","authors":"Maxime Phalempin ,&nbsp;Nils Jentzsch ,&nbsp;John Maximilian Köhne ,&nbsp;Susanne Schreiter ,&nbsp;Ralf Gründling ,&nbsp;Doris Vetterlein ,&nbsp;Steffen Schlüter","doi":"10.1016/j.still.2025.106561","DOIUrl":"10.1016/j.still.2025.106561","url":null,"abstract":"<div><div>The development of soil structure is a complex process driven by the interplay of physical, biological, and chemical factors. Plant roots play an important role in shaping the porous soil architecture; however, their relative contribution is hard to quantify. This study assessed root-driven structural (bio-)pore formation, its impact on hydraulic properties (e.g., infiltration capacity), and how it is influenced by soil texture (loam vs. sand). We combined X-ray computed tomography and machine learning-based segmentation to analyze 720 soil cores from a five-year chronosequence of maize cultivation without tillage. With this methodology, we showed that soil texture was the primary driver of soil structure development and the dynamics of root-derived organic matter. In loam, rapid root decomposition left an interconnected biopore network, enhancing infiltration despite soil settlement. In sand, a greater accumulation of root-derived particulate organic matter resulted from more vigorous root growth, larger diameters, and slower root decomposition. In sand, soil settlement reduced the infiltration capacity over time. These findings underscore the need to integrate organic matter dynamics into soil structure studies, with implications for sustainable land management and carbon storage strategies. Expanding this approach to diverse soils and climates could improve soil process modeling and soil management globally.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"251 ","pages":"Article 106561"},"PeriodicalIF":6.1,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143725739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Faster soil organic carbon turnover in MAOM versus POM: straw input causes larger microbial driven soil organic carbon decomposition but higher straw accumulation in MAOM","authors":"Xiongsheng Yu ,&nbsp;Lili Wang ,&nbsp;Qiang Wang ,&nbsp;Guoyan Zhou ,&nbsp;Han Sun ,&nbsp;Georg Guggenberger ,&nbsp;Yongfu Li ,&nbsp;Kuzyakov Yakov ,&nbsp;Yu Luo ,&nbsp;Yingyi Fu","doi":"10.1016/j.still.2025.106549","DOIUrl":"10.1016/j.still.2025.106549","url":null,"abstract":"<div><div>Straw-related carbon (C) dynamics are central for soil organic C (SOC) accrual in soils. However, the underlying microbial groups driving straw decomposition and accumulation in particulate organic matter (POM) and mineral-associated organic matter (MAOM) remain elusive. This study effectively isolated POM and MAOM by using ultrasonic energy (kept below 80 J mL⁻¹) and size-density fractionation that minimally impacts microbial activity and community. We further conducted an 87-day incubation to examine the transformation of added C4 straw and the involved bacterial mechanisms in POM and MAOM. Here, we showed that: i) SOC turnover was faster in MAOM compared to POM, as MAOM stabilized more straw C, likely through strong organic-mineral interactions, while exhibiting significantly higher SOC mineralization than POM over the incubation period; and ii) MAOM, versus POM, exhibited difference of bacterial community and metabolisms during incubation. For instance, microorganisms within MAOM were enriched with genes involved in i) decomposing easily utilized C sources (e.g., sugars, pectin) and ii) the pathways of microbial biomass synthesis. This led to faster SOC turnover via larger native SOC decomposition (possibly through co-metabolism mechanisms) and higher new SOC formation (possibly through biomass-necromass accumulation). Conversely, POM enriched with K-strategists and genes encoding enzymes decomposing recalcitrant C sources (e.g., cellulose, hemicellulose, lignin), possibly via nitrogen mining as nutrients were exhausted in the later stage. This study firstly reveals the bacterial drivers involved in straw-C transformation within POM and MAOM by proper separating approach and highlights the different bacterial community and their metabolisms underpinning added straw decomposition and consequent C accrual in POM and MAOM.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"251 ","pages":"Article 106549"},"PeriodicalIF":6.1,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143704023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rice yield and nutrient dynamics in a fertilizer-free and agrochemical-free paddy field with inter-tillage weeding","authors":"Zhiduo Zhou ,&nbsp;Shoichiro Hamamoto ,&nbsp;Junichi Kashiwagi ,&nbsp;Yan Zhu ,&nbsp;Munehide Ishiguro ,&nbsp;Hajime Araki","doi":"10.1016/j.still.2025.106531","DOIUrl":"10.1016/j.still.2025.106531","url":null,"abstract":"<div><div>Excessive fertilizer and agrochemical applications cause many environmental problems. Some studies in Japan have indicated that high yields can be obtained without fertilizers and agrochemicals and with frequent inter-tillage weeding. After conversion from conventional cultivation, we evaluated the plant conditions and soil nutrients of this cultivation system for five years (2018–2022) under three different inter-tillage frequencies: no inter-tillage (0-T), twice inter-tillage (2-T), and five times inter-tillage (5-T). Control plots (CI) were established in 2022, where fertilizers and chemicals were applied as a conventional method, to compare the yield. In the inter-tillage fields, the yield significantly decreased in the second year but increased in the fourth year, ultimately reaching 81 % of the fertilized control field yield in the final year. Higher frequency inter-tillage weeding improved rice growth by suppressing weeds within one season. Soil ammonium concentration and nitrogen in plants decreased in the second and third years and began to recover, contributing to increased yield. Without fertilizer application, the soil carbon content increased while the soil total nitrogen content decreased, and nitrogen mineralization is expected to be promoted with long-term inter-tillage practices. Different mechanical tillage before transplanting and inter-tillage weeding during the cultivation season did not affect soil organic carbon content. Phosphorus, potassium, and silica deficiency did not occur during the five years without fertilizer input. These results provide a fundamental understanding of fertilizer- and agrochemical-free rice cultivation and contribute to the development of new sustainable cultivation systems to reduce fertilizer and agrochemical applications.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"251 ","pages":"Article 106531"},"PeriodicalIF":6.1,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143696032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Wood gasification biochar enhances soil carbon sequestration without affecting greenhouse gas fluxes or wheat yield in sub-alkaline soil","authors":"Laura Trozzo ,&nbsp;Paride D’Ottavio ,&nbsp;Ayaka Wenhong Kishimoto-Mo ,&nbsp;Matteo Francioni","doi":"10.1016/j.still.2025.106556","DOIUrl":"10.1016/j.still.2025.106556","url":null,"abstract":"<div><div>The agricultural sector plays a vital role in mitigating soil greenhouse gas (GHG) emissions and enhancing carbon sequestration. One promising approach is wood biochar produced through gasification, which generates both syngas and stable biochar. This study evaluates the effects of wood gasification biochar (WGB) on subalkaline soil under Mediterranean climate conditions. A field experiment was conducted over two cropping years, monitoring soil N₂O, CH₄, and CO₂ fluxes, along with temperature and water content, for two treatments: unamended wheat (control) and wheat amended with 60 Mg ha⁻¹ of WGB. Additionally, soil physicochemical properties at 0–10 cm and 10–40 cm depths and wheat yield were assessed. In the WGB treatment, soil N₂O, CH₄, and CO₂ fluxes remained unchanged, though a slight increase in soil temperature (+0.1 °C) was observed. No significant differences were detected in soil pH, total and ammoniacal nitrogen, bulk density, or cation exchange capacity. However, soil nitric nitrogen levels significantly decreased. Soil carbon stock increased 2.2-fold at 0–10 cm and 1.4-fold at 10–40 cm, with this effect persisting into the second year. Wheat yield remained comparable between treatments, averaging ∼2.0 Mg ha⁻¹ (control) vs. ∼1.8 Mg ha⁻¹ (WGB) in year one and ∼3.9 Mg ha⁻¹ vs. ∼3.1 Mg ha⁻¹ in year two. These findings indicate that wood gasification biochar enhances soil carbon sequestration without affecting GHG emissions or wheat yield, reinforcing its potential for sustainable soil management and circular agriculture.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"251 ","pages":"Article 106556"},"PeriodicalIF":6.1,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanical properties and microstructural evolution of Malan loess with depth: Insights from multivariate statistical models","authors":"Xuanyu Gao ,&nbsp;Wanli Xie ,&nbsp;Kangze Yuan ,&nbsp;Qiqi Liu","doi":"10.1016/j.still.2025.106548","DOIUrl":"10.1016/j.still.2025.106548","url":null,"abstract":"<div><div>Malan loess is widely distributed on the Chinese Loess Plateau and poses great challenges to geotechnical, ecological, and agricultural practices due to its unique structure and collapsibility. It is essential to understand the evolution of these properties with depth to assess soil stability and reduce engineering risks in the area. This study investigates the mechanical properties and microstructural evolution of Malan loess with depth and employs multivariate statistical methods to explore their complex interrelationships. Oedometer-collapse tests reveal a 94.2 % reduction in collapsibility coefficient (<em>δ</em>_<em>s</em>) from 0.0722 at 1 m to 0.0042 at 9 m, indicating a significant reduction in collapsibility with increasing depth. According to the results of the direct shear test, it showed that the shear strength initially decreases and then increases due to the combined effect of the water content and dry density. Scanning electron microscopy (SEM) images reveal the densification of the loess structure, with changes in particle contact from point to face contact and the evolution from macropores to mesopores and small pores as depth increases. Quantitative analysis by Avzio showed a decrease of 61.5 % in macropores area and an increase of 62.5 % in small pores area. The results obtained by Pearson’s correlation analysis and random forest model showed that among these microstructural characteristics, the total pore area (<em>%IncMSE</em> = 22.77 %) is the most important factor influencing the collapsibility properties of loess and water content (<em>%IncMSE</em> = 17.72 %) acts a key role in controlling shear strength. Additionally, compared to traditional methods, the random forest model offers a more insightful understanding of nonlinear relationships and multifactorial coupling effects. These findings provide scientific guidance for geotechnical engineering in loess regions, aiding in risk mitigation and promoting sustainable construction.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"251 ","pages":"Article 106548"},"PeriodicalIF":6.1,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143675580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}