Soil & Tillage Research最新文献

{"title":"Morphology-based mechanism of desiccation cracking in soil and montmorillonite","authors":"Jia Xu ,&nbsp;Yidi Qin ,&nbsp;A.Liman Kakewati ,&nbsp;Shuchao Liu ,&nbsp;Paul D. Hallett ,&nbsp;Gang Liu","doi":"10.1016/j.still.2025.106474","DOIUrl":"10.1016/j.still.2025.106474","url":null,"abstract":"<div><div>Cracking from soil desiccation is a common phenomenon. Stress analysis based on transient spatial distribution of soil water and fracture mechanics has been extensively applied in studying the development of soil cracks. Nevertheless, the existing experiments and theoretical models for soil crack development generally ignore the interaction between cracks, and lack quantitative analysis of the transient evolution of crack length <em>L</em>(<em>t</em>) and crack strength <em>I</em>(<em>t</em>). This study explored the transient evolution of soil and montmorillonite shrinkage and cracking by analyzing the images from both field and laboratory experiments. Our study demonstrated that in the initial stages of drying, newly formed cracks accelerated the soil moisture evaporation near the crack opening interface, resulting in a rapid increase in stress, which promoted an exponential growth of the cracks. Subsequently, the general case where two or more parallel cracks have a mutual shielding interaction led to slowing down and saturation of their development. The experimental <em>L</em>(<em>t</em>) and <em>I</em>(<em>t</em>) curves for the S-shape could be well-fitted by introducing the existence of a competitive relationship between cracks. The experimental results also showed that the <em>I</em>(<em>t</em>) curve lagged behind <em>L</em>(<em>t</em>). The shielding effect between cracks was also supported by imaging of all crack samples. Hence, the single-crack model commonly used in traditional soil desiccation cracking studies is unsuitable for analyzing cracks in soil samples. Finally, the analysis of the concave-shaped soil shrinkage characteristic curve (SSCC) and the concave-shaped the soil water evaporation curve for all soil samples revealed that they could not explain the S-shaped <em>L</em>(<em>t</em>) and <em>I</em>(<em>t</em>) curves. Therefore, the plausibility of the single or isolated crack model for the evolution of soil drying and cracking was excluded. Finally, this experimental study proposed the hypothesis that the saturation phenomena of <em>L</em>(<em>t</em>) and <em>I</em>(<em>t</em>) are likely due to the competition between cracks for the release of strain energy caused by drying.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"249 ","pages":"Article 106474"},"PeriodicalIF":6.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143325190","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":"Dynamic changes of soil aggregate-associated phosphorus adsorption-desorption characteristics in a chronosequence of Chinese fir plantations","authors":"Zhe Zhang ,&nbsp;Zhiyao Wang ,&nbsp;Shaoming Ye ,&nbsp;Shengqiang Wang","doi":"10.1016/j.still.2025.106479","DOIUrl":"10.1016/j.still.2025.106479","url":null,"abstract":"<div><div>Successive cultivation of Chinese fir affects soil phosphorus (P) adsorption-desorption characteristics by altering both abiotic and biotic factors, such as soil aggregate size and microbial activities. However, previous studies have predominantly focused on individual factors (abiotic or biotic factors) without considering their combined effects on soil P adsorption-desorption characteristics. To address the research gaps, this study was conducted to investigate the response of abiotic factors (P forms, soil organic matters (SOM), iron and aluminum oxides (Fe₂O₃ and Al₂O₃) concentrations, and aggregate sizes) and biotic factors (microbial activities) to Chinese fir stand ages (control, 9-yr, 17-yr, and 26-yr) and how the combined relationship affect P adsorption-desorption characteristics in Chinese fir plantations. The results showed that under the same initial P concentration (0.0, 0.3, 1.5, 3.0, 10.0, 20.0, and 50.0 mg L⁻¹), parameters of P adsorption-desorption characteristics including the quantity of stable adsorption P, quantity of stable desorption P, adsorption P rate, and desorption P rate in macro-aggregates (&gt; 0.25 mm) were significantly higher than that in the micro-aggregates (&lt; 0.25 mm). However, in 26-yr of Chinese fir plantations, parameters of P adsorption-desorption characteristics within almost all aggregate fractions significantly decreased, driven by declines in inorganic P, SOM, amorphous Fe₂O₃ and Al₂O₃, macro-aggregates, and microbial biomass (as indicated by PLFAs). The order of factors affecting P adsorption-desorption characteristics variation is P forms, SOM, microbial biomass, and Fe₂O₃ and Al₂O₃. The results of this study indicate crucial factors affecting the P adsorption-desorption process, with a combined effect of abiotic factors within the culture of Chinese fir. Therefore, to prevent significant soil P losses and promote P utilization efficiency, it is crucial to consider the combined impacts of abiotic and biotic factors on soil P cycling characteristics across different stand ages during Chinese fir cultivation.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"249 ","pages":"Article 106479"},"PeriodicalIF":6.1,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143357313","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 Epichloë fungal endophyte-tall fescue symbiosis on mechanical characteristics of rooted soil depending on the host genotype","authors":"Nasrin Saadati ,&nbsp;Mohammad R. Mosaddeghi ,&nbsp;Mohammad R. Sabzalian ,&nbsp;Mehrnoosh Jafari","doi":"10.1016/j.still.2025.106472","DOIUrl":"10.1016/j.still.2025.106472","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Although the soil reinforcement by fibrous roots has been studied, the interaction impacts of endophyte symbiosis and plant genotype on mechanical characteristics of rooted soil have not been investigated yet. This study was conducted to explore the effects of endophyte symbiosis (&lt;em&gt;Epichloë coenophiala&lt;/em&gt;) with tall fescue (&lt;em&gt;Festuca arundinacea&lt;/em&gt;) genotypes (75B and 75 C) on root reinforcement of a sandy clay loam soil. Glasshouse grown plants with (E+) and without (E−) endophytes were tested for shear characteristics (i.e., shear strength, &lt;em&gt;S&lt;/em&gt;&lt;sub&gt;f&lt;/sub&gt;, relative shear displacement, RSD&lt;sub&gt;f&lt;/sub&gt;, and strain energy, &lt;em&gt;E&lt;/em&gt;&lt;sub&gt;strain&lt;/sub&gt;) at depths of 10, 25 and 40 cm and two matric potentials (–10 and 0 kPa) measured using a large direct shear machine. Soil reinforcement by roots was related to root area ratio (RAR, ratio of root area to soil cross-section area), chemical composition and biomechanical characteristics (i.e., tensile strength, &lt;em&gt;σ&lt;/em&gt;&lt;sub&gt;Y&lt;/sub&gt;, and tensile strain-at-failure, &lt;em&gt;ϵ&lt;/em&gt;&lt;sub&gt;Y&lt;/sub&gt;, determined by an Instron universal tension-compression device). The roots increased &lt;em&gt;S&lt;/em&gt;&lt;sub&gt;f&lt;/sub&gt;, RSD&lt;sub&gt;f&lt;/sub&gt; and &lt;em&gt;E&lt;/em&gt;&lt;sub&gt;strain&lt;/sub&gt; by 4.1x, 4.5x and 14.5x compared to the root-free soil, respectively, with endophytes causing a further increase for 75 C but not for 75B. Cellulose and cellulose/lignin ratio were higher in the 75 C roots than the 75B roots. Cellulose, cellulose/lignin ratio, &lt;em&gt;σ&lt;/em&gt;&lt;sub&gt;Y&lt;/sub&gt; and &lt;em&gt;ϵ&lt;/em&gt;&lt;sub&gt;Y&lt;/sub&gt; were always greater in the E+ plants than in the E− ones, although the effect of endophyte was more noticeable in 75 C. Largest reinforcement was recorded for 75 C E+ (i.e., &lt;em&gt;S&lt;/em&gt;&lt;sub&gt;f&lt;/sub&gt; of 36.5 kPa, RSD&lt;sub&gt;f&lt;/sub&gt; of 29.1 %, and &lt;em&gt;E&lt;/em&gt;&lt;sub&gt;strain&lt;/sub&gt; of 5.89 kJ m&lt;sup&gt;−3&lt;/sup&gt;), followed by 75B E+ &gt; 75B E– ≈ 75 C E–, directly related to ruptured+stretched roots’ numbers, RAR, root cellulose, cellulose/lignin ratio, &lt;em&gt;σ&lt;/em&gt;&lt;sub&gt;Y&lt;/sub&gt; and &lt;em&gt;ϵ&lt;/em&gt;&lt;sub&gt;Y&lt;/sub&gt;. Compared to &lt;em&gt;S&lt;/em&gt;&lt;sub&gt;f&lt;/sub&gt; and RSD&lt;sub&gt;f&lt;/sub&gt;, the &lt;em&gt;E&lt;/em&gt;&lt;sub&gt;strain&lt;/sub&gt; better discriminated the reinforcing effect of root/endophyte. Lower reinforcement was observed at saturated condition, and root/endophyte moderated the influence of matric potential on soil reinforcement. The 75 C roots (irrespective of endophyte) could effectively reinforce the soil (high slopes of &lt;em&gt;S&lt;/em&gt;&lt;sub&gt;f&lt;/sub&gt;–RAR relations). But, the reinforcing effect of 75B E– roots was low and significantly increased due to endophyte presence. The 75 C roots predominantly reinforced upper layers while 75B roots mainly reinforced lower layers. In 75 C, endophyte’s effect was significant for depths &gt; 10 cm; however, the endophyte’s effect in 75B was significant for depth of 10 cm. The 75 C roots could effectively reinforce soil irrespective of matric potential, but 75B roots mainly reinforced unsaturated soil. Overall, genotype selection of tall fescue associated wit","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"248 ","pages":"Article 106472"},"PeriodicalIF":6.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172277","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":"Hydrogen sulfide and earthworm casts can synergistically increase the cycling rate of soil arsenic","authors":"Van M. Dinh ,&nbsp;Le N.H. Pham ,&nbsp;Ngan T. Nguyen ,&nbsp;Quan T. Dang ,&nbsp;Phuong M. Le ,&nbsp;Linh T. Nguyen ,&nbsp;Anh T.Q. Nguyen ,&nbsp;Minh N. Nguyen","doi":"10.1016/j.still.2025.106476","DOIUrl":"10.1016/j.still.2025.106476","url":null,"abstract":"<div><div>Earthworm casts are a seasonal and freshly formed part of soil that contains highly reactive compounds, including nutrients, e.g., phosphorus and sulfur, and toxic elements, e.g., arsenic (As). Casts are dissociated and lost due to biodecomposition or field care practices. However, there exists a knowledge gap concerning the dissociation of casts and the fate of associated compounds, particularly As. Dissociation of the microstructure of earthworm casts is hypothesized to result in the release of As, and in this study, this phenomenon was investigated under an atmosphere consisting of hydrogen sulfide (H₂S), a common anoxic gas in paddy environments. Batch experiments were carried out over a time span of 10 days. Factors such as zeta potential (ζ), hydrodynamic size (d_h) and transmission (T), which reflect possible electrostatic interactions and the dissociation dynamics of cast suspensions, were evaluated by dynamic light scattering and test tube-based analysis methods. The amounts of As and other elements (e.g., P, Si, Fe, dissolved organic carbon) released from the cast suspensions were also tracked. The results show that the ζ, d_h, and T values of the cast suspensions decreased over time, while pH increased. Cast samples exhibited a less negatively charged surface, smaller size, and higher dispersibility in the presence of H₂S compared to samples without H₂S. Intensified releases of Fe, Si and DOC were also observed in the presence of H₂S. This suggests that H₂S facilitated the dissociation of the casts by dissolving cast constituents such as Fe oxides, silicates and organic matter. It can be inferred that the formation/diffusion of H₂S in soil, particularly sulfate-containing soils, can accelerate cast cycling and mobilize cast-containing pollutants (e.g., As). Therefore, field management practices that reduce the reactivity of H₂S need to be considered.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"248 ","pages":"Article 106476"},"PeriodicalIF":6.1,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172276","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":"Spatial and temporal evolution of soil organic matter and its response to dynamic factors in the Southern part of Black Soil Region of Northeast China","authors":"Xingnan Liu ,&nbsp;Mingchang Wang ,&nbsp;Ziwei Liu ,&nbsp;Xiaoyan Li ,&nbsp;Xue Ji ,&nbsp;Fengyan Wang","doi":"10.1016/j.still.2025.106475","DOIUrl":"10.1016/j.still.2025.106475","url":null,"abstract":"<div><div>Soil organic matter content (SOMC) is decreasing in the Black Soil Region of Northeast China (BSRNC) due to the combined impacts of prolonged agricultural reclamation, climate change, and soil erosion. As an essential soil quality indicator, it is urgent to analyze the dynamic characteristics of Soil organic matter (SOM). This study aims to evaluate the spatial and temporal dynamics of SOMC and identify the factors driving these changes. Two sets of soil data collected in the 1980s and 2020 were compared in the southern part of BSRNC. Five machine learning models were used to estimate the spatial distribution of surface SOMC during these two periods, and the accuracy of the five models was evaluated. Simultaneously, the factors leading to SOM's spatial variability and temporal change were assessed. The results showed that Extreme Gradient Boosting (XGBoost) had the best performance with R² of 0.65 and 0.78 for the 1980s and 2020, respectively. Spatially, SOMC was lower and decreased more in the western saline agglomeration than in other parts of the study area. Soil properties (bulk density, silt, pH) and climate (temperature, precipitation) were key factors that affected the spatial variability in SOM. Temporally, SOMC decreased from 22.8 ± 4.5 g·kg⁻¹ in the 1980s to 20.3 ± 4.4 g·kg⁻¹ in 2020, and the average content reduced by 2.5 g·kg⁻¹ overall. This study revealed that the loss of SOMC increases with soil erosion. Land use also affects change in SOM. The most severe decrease in SOM occurred when forests were reclaimed as drylands (-6.2 g·kg⁻¹). In the past 40 years, increasing temperatures have been accompanied by a decrease in SOM, while increasing precipitation has had little positive effect on SOM. The coupled effect of land use change and soil erosion had the highest contribution rate to SOMC changes, at 8.66 %, followed by the independent effect of soil erosion at 6.40 %. To summarize, this study clarified spatial variability and temporal change in SOM and elucidated the mechanism of dynamic factors affecting SOM, which can guide the design of sustainable agricultural policies.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"248 ","pages":"Article 106475"},"PeriodicalIF":6.1,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104357","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":"Adaptive regulation of microbial community characteristics in response to nutrient limitations under mulching practices across distinct climate zones","authors":"Ke Dang ,&nbsp;Haofeng Liang ,&nbsp;Shuqing Guo ,&nbsp;Zihan Fan ,&nbsp;Hongbing Li ,&nbsp;Mingsheng Ma ,&nbsp;Suiqi Zhang","doi":"10.1016/j.still.2025.106465","DOIUrl":"10.1016/j.still.2025.106465","url":null,"abstract":"<div><div>Soil nutrient stoichiometric imbalance result in nutrient limitation for microbial metabolism, which subsequently affects the microbial community structure. However, the differences in microbial metabolic limitations and adaptive regulatory strategies of microorganisms in response to mulching practices and varying climatic conditions have not yet been fully clarified. This study evaluates three treatments, straw mulch planting (SM), plastic-film mulch planting (PM), and conventional flat planting (CK) to assess the response of microbial metabolic limitation and community structures to mulching measures across three climate zones: the temperate semi-arid zone (Yuzhong), the mid-temperate semi-arid zone (Dingxi), and the warm temperate semi-humid zone (Changwu) in the Loess Plateau, China. The results indicate that microbial metabolism had strong relative carbon (C) and phosphorus (P) limitations at our study sites. Soil nutrient imbalances caused by mulching measures under different climatic conditions alter the degree of microbial nutrient limitation. Compared with CK, microbial P limitation under the SM treatments was 5.9 % lower, with the largest reduction in Changwu, whereas the PM treatment increased microbial P limitation by 4.1 %, with the largest increase in Yuzhong. The microbial community structures in Yuzhong and Dingxi exhibit greater sensitivity to soil physicochemical properties and microbial metabolic limitations. The bacterial Chao1 index in PM in Yuzhong and Dingxi and the fungal Chao1 index in SM in Yuzhong significantly increased relative to CK. Mulching measures had no significant effect on bacterial and fungal diversity or bacterial abundance in Changwu. Furthermore, redundancy discriminant analysis demonstrated that the variable explanations of soil physicochemical properties, stoichiometry, and microbial resource limitations were higher in Yuzhong and Dingxi than in Changwu. Further, soil water content and vector angle were the main factors driving the separation of soil samples at the microbial order level. All in all, these results enhance our understanding of how mulching measures regulate microbial communities across different climatic regions, particularly in response to varying precipitation patterns. Further research is needed to determine how mulch-induced nutritional limitation changes the ecological functions of microbes in agroecosystems.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"248 ","pages":"Article 106465"},"PeriodicalIF":6.1,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072328","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":"Vetch cover crops reduce the magnitude of citrus rhizosphere effect on plant-derived carbon by promoting suberin and lignin phenol accumulation in citrus orchard","authors":"Jiajia Zhang ,&nbsp;Xin Yang ,&nbsp;Lixiong Zeng ,&nbsp;Jianwen Hu ,&nbsp;Willam R. Horwath ,&nbsp;Zunji Jian ,&nbsp;Hongbing Yang ,&nbsp;Fuhua Li ,&nbsp;Lei Lei ,&nbsp;Wenfa Xiao","doi":"10.1016/j.still.2025.106469","DOIUrl":"10.1016/j.still.2025.106469","url":null,"abstract":"<div><div>The rhizosphere is an important interface for plant carbon (C) input. The rhizosphere effect (RE) plays a substantial role in soil C maintenance and stabilisation. However, it remains unclear how the RE interacts with various residual C sources, such as plant and microbial residues from green manure planting in orchards. We examined the plant- and microbial-derived C contents in the rhizosphere and bulk soil under two management practices of smooth vetch (<em>Vicia villosa</em> var. <em>glabresens</em>) cover and clean tillage. The citrus RE on plant-derived C shifted from positive to negative due to the increase in total root biomass and the carbon/nitrogen ratio of vetch roots and leaves. This shift led to a significantly higher accumulation of lignin phenols (40.64 %, 31.60 %) and suberin (95.71 %, 59.02 %) in the rhizosphere compared to bulk soil. The magnitude of the citrus RE on microbial-derived C was enhanced, primarily driven by increases in soil carbon/phosphorus and nitrogen/phosphorus ratios, and the fungi-to-bacteria ratio (41 % in rhizosphere soil). Additionally, a decrease in the gram-positive-to-gram-negative bacteria ratio in the rhizosphere soil contributed to this effect. Finally, vetch decreased fungal (-22.77 %, −24.52 %) and microbial necromass C (-16.10 %, −13.74 %) in rhizosphere and bulk soil respectively. Partial least squares path modelling showed that vetch characteristics (total effect −1.01) were key contributors to citrus RE on plant-derived C, whereas edaphic variables (total effect 1.86) played an essential role in citrus RE on microbial-derived C in orchards under vetch cover. The results of this study contribute to a comprehensive understanding of the mechanisms underlying the RE on soil C accumulation in orchards managed with green manure.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"248 ","pages":"Article 106469"},"PeriodicalIF":6.1,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072327","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":"Adsorbent application and nitrogen deep placement reduced ammonia emissions in wheat fields","authors":"Yang Yang ,&nbsp;Weizheng Shu ,&nbsp;Ye Yang ,&nbsp;Xiaoyu Ni ,&nbsp;Yuejin Wu ,&nbsp;Wenge Wu ,&nbsp;Na Li","doi":"10.1016/j.still.2025.106456","DOIUrl":"10.1016/j.still.2025.106456","url":null,"abstract":"<div><div>Increasing soil ammonium (NH₄⁺) adsorption and nitrogen (N) application depth may be beneficial for reducing ammonia (NH₃) emissions. However, there is little consensus about the combined effects of adsorbent application and N application depth on field NH₃ emissions. The study aimed to investigate the combined effects of adsorbent (humic acid-modified montmorillonite) application and N deep placement on NH₃ emissions in wheat fields. A three-year field experiment was conducted during 2020−2023. The nine treatments included the control test (CK), adsorbent applied in 0−10 cm layer (A1), adsorbent applied in 10−20 cm layer (A2), N applied in 0−10 cm layer (N1), N and adsorbent applied in 0−10 cm layer (N1A1), N applied in 0−10 cm layer and adsorbent applied in 10−20 cm layer (N1A2), N applied in 10−20 cm layer (N2), N applied in 10−20 cm layer and adsorbent applied in 0−10 cm layer (N2A1), and N and adsorbent applied in 10−20 cm layer (N2A2). Results showed that field NH₃ emissions ranged 3.88−7.76 kg N ha⁻¹ in the treatments without N application and 10.00−25.86 kg N ha⁻¹ in N-applied treatments. The greater NH₃ emissions with N application were partly attributed to the higher soil NH₄⁺ concentration, pH, and temperature and the lower volumetric water content. Adsorbent application reduced NH₃ emissions by 2.0 %−42.3 % because it increased soil adsorption of NH₄⁺. N deep placement reduced soil pH and NH₄⁺ concentration in 0−10 cm layers, and then decreased NH₃ emissions by 20.0 %−50.1 % (<em>p</em> &lt; 0.05). A combination of adsorbent application and N shallow application led to similar NH₃ emissions as N deep placement, while it also led to greater wheat grain yield and biomass. NH₃ emissions were 13.5 %−51.5 % lower in N2A2 than in other N-applied treatments. Overall, adsorbent application and N deep placement reduced NH₃ emissions and improved wheat productivity, and thus is a promising practice in wheat production.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"248 ","pages":"Article 106456"},"PeriodicalIF":6.1,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072329","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":"Field-saturated and near-saturated soil hydraulic conductivity as influenced by conventional and soil health management systems","authors":"Anuradha Garg ,&nbsp;Samuel Kwakye ,&nbsp;Anna Cates ,&nbsp;Heidi Peterson ,&nbsp;Kathryn LaBine ,&nbsp;Greg Olson ,&nbsp;Vasudha Sharma","doi":"10.1016/j.still.2025.106467","DOIUrl":"10.1016/j.still.2025.106467","url":null,"abstract":"<div><div>Agricultural management practices can influence soil structure and health in the long term. Hydraulic conductivity (cm/s), indicating the soil’s ability to transport water through its profile in both near-saturated (<em>K</em>) and field-saturated conditions (<em>K</em>_<em>fs</em>), is a key parameter to assess soil’s hydrological characteristics. This study investigated the impact of two different management practices (soil health versus conventional) on hydraulic conductivity. Two pairs of sites in Olmsted and Freeborn counties of Minnesota, USA, were studied for two years (2022 and 2023) to analyze the variability over the growing season. Results demonstrated that <em>K</em> showed variable response to the agricultural management systems. The values were observed to be higher in conventional fields in June while in August, soil health sites exhibited higher conductivity. The effect of time on <em>K</em> was much stronger (<em>p</em> &lt;&lt; 0.01) than management (<em>p</em> &gt; 0.05), while their interaction also significantly influenced the <em>K</em> values (<em>p</em> &lt; 0.01). Field-saturated hydraulic conductivity (<em>K</em>_<em>fs</em>) was found to be higher in conventional fields (<em>p</em> &lt; 0.01) but was also moderately affected by the time of measurement (<em>p</em> &lt; 0.05). It is important to note that <em>K</em> represents hydraulic conductivity of the soil matrix while <em>K</em>_<em>fs</em> accounts for the water flow through soil’s structured media (including cracks, wormholes, etc.). Our results suggested that preferential flow paths were more prevalent in conventional fields, while the soil matrix responded differently over the growing season in soil health and conventional fields. Considering the growing focus on soil health practices, this study highlights crucial findings related to the hydrological impacts of different agricultural management systems.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"248 ","pages":"Article 106467"},"PeriodicalIF":6.1,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072403","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":"Size sorting in rill detachment for a typical silt loam on the Loess Plateau","authors":"Qiming Zhu,&nbsp;Jun’e Liu,&nbsp;Xiaoqian Qi,&nbsp;Xike Cheng,&nbsp;Zhengchao Zhou","doi":"10.1016/j.still.2025.106470","DOIUrl":"10.1016/j.still.2025.106470","url":null,"abstract":"<div><div>Soil detachment is the initial subprocess of soil erosion, and provides sediment for subsequent sediment transport and deposition. Understanding the size sorting mechanisms during soil detachment is crucial for advancing our knowledge of soil erosion. To investigate these mechanisms, a typical silt loam from the Loess Plateau was selected, and PVC rill flume tests (3 m × 0.1 m × 0.05 m) were conducted at four slopes (9°, 12°, 15°, and 18°) and five flow discharges (3, 5, 7, 9, and 11 L min⁻¹). The results indicated that the effective median particle size (<em>D</em>₅₀) of the detached sediment was smaller than that of the original soil, whereas the ultimate value was larger. The effective <em>D</em>₅₀ decreased with increasing slope but exhibited an initial increase followed by a decrease as the flow discharge increased. The sediment primarily consisted of effective fine and coarse silt, with a higher content of effective fine silt than the original soil. Under the experimental conditions, a flow discharge of 7 L min⁻¹ was identified as the critical point at which the influence of the flow discharge on the selectivity of effective particles began to stabilize. During rill detachment, most fine or medium-to-coarse sand particles were agglomerated by clay and fine silt particles. Particles smaller than 21.66 μm or larger than 119.38 μm were prone to detachment. These findings could enhance the understanding of sorting mechanisms during rill detachment, and provide a theoretical basis for preventing and mitigating of soil erosion on the Loess Plateau.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"248 ","pages":"Article 106470"},"PeriodicalIF":6.1,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072326","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}