Soil & Tillage Research最新文献

{"title":"Vertical dynamics of soil organic carbon sequestration under contrasting groundwater table levels after 35-year straw return","authors":"Shuai Liu ,&nbsp;Yue Dong ,&nbsp;Milton Halder ,&nbsp;Samuel Adingo ,&nbsp;Lichu Yin ,&nbsp;Hu. Zhou ,&nbsp;Yan Ma ,&nbsp;Xinhua Peng","doi":"10.1016/j.still.2025.106580","DOIUrl":"10.1016/j.still.2025.106580","url":null,"abstract":"<div><div>Various groundwater table levels in paddy soil aggravate the complexity of soil organic carbon (SOC) sequestration under redox conditions. We investigated a long-term experimental field consisting of two groundwater tables (SWT, shallow groundwater table; DWT, deep groundwater table) and three straw application rates (NPK, without straw return; LOM, low rate of straw return; HOM, high rate of straw return). Soil samples from 0–10, 10–20 and 20–40 cm soil layers were collected and analyzed. Results revealed that SOC fraction contents significantly decreased with increasing soil depth, while SOC stability showed an opposite trend (<em>P</em> &lt; 0.05). In the 0–20 cm soil layer, straw return increased SOC fraction concentrations, resulting in higher C stocks. In the 20–40 cm soil layer, a significant decrease in SOC was explained by remarkable MOC reduction with straw addition under SWT (<em>P</em> &lt; 0.05), whereas no significant changes were observed under DWT. Relative to NPK, straw application notably increased the proportions of O-alkyl C and Carbonyl C under SWT and DWT in topsoil layer, respectively (<em>P</em> &lt; 0.05). In the deep soil layer, straw addition increased Aromatic C but decreased O-alkyl C proportions under SWT, resulting in higher aromaticity and hydrophobicity (<em>P</em> &lt; 0.05), while contrasting changing patterns were observed under DWT when compared to NPK. Hierarchical clustering analysis indicated that soil properties and SOC dynamics were primarily determined by straw return under SWT, while mainly driven by soil depth under DWT. This study highlights the importance of understanding the dynamics of SOC throughout the whole profile to groundwater table management. A preferable straw return strategy is proposed for different groundwater management based on the trade-off between economic and environmental benefits. A lower straw return amount was suggested under SWT from an economic perspective, whereas a higher straw return amount was recommended under DWT treatment for the higher increase of SOC.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"252 ","pages":"Article 106580"},"PeriodicalIF":6.1,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823264","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":"Interaction effects of organic mulch application rates and rainfall intensities on soil and water loss in karst sloping farmlands: Insights from a laboratory simulation experiment","authors":"Panpan Wu ,&nbsp;Rui Li ,&nbsp;Feiyang Cai ,&nbsp;Ling Xiong ,&nbsp;Zhengyi Tang ,&nbsp;Linlv Xiao","doi":"10.1016/j.still.2025.106574","DOIUrl":"10.1016/j.still.2025.106574","url":null,"abstract":"<div><div>Sloping farmland constitutes the primary source of soil and water loss in Southwest China. However, research and practice on organic mulching, one of the key soil and water conservation measures, have been relatively limited in karst regions. The questions of whether there are significant differences in the effectiveness of various types for organic mulches in diminishing runoff and sediment on karst sloping farmlands, and whether the interactions between organic application rates and rainfall significantly influence runoff and sediment loss, have not been systematically addressed. Therefore, the study employs simulation experiments to investigate the influence of six application rates (0 %, 30 %, 40 %, 50 %, 60 %, and 70 %) of litter, straw, and biochar under three rainfall intensities (30, 60 and 90 mm/h) for soil and water loss in karst sloping farmlands. A regression model was used to analyze the relationships between rainfall, application rates, interaction terms, and the runoff yield rate (<em>Rr</em>) and sediment yield rate (<em>Sr</em>). The results indicated that <em>Rr</em> and <em>Sr</em> decrease with increasing application rates and increased with prolonged rainfall duration. Runoff and sediment reduction efficiencies (<em>R</em>RE<!--> <!--> and <em>S</em>RE<!--> <!-->) rose with higher application rates, and the effectiveness (p &lt; 0.05) of the three organic mulches on <em>Rr</em> and <em>Sr</em> varied significantly. The <em>R</em>RE<!--> <!--> and <em>S</em>RE<!--> <!--> for litter were the highest (44.05 %, 81.27 %), followed by straw (34.00 %, 46.53 %), while biochar had the lowest (31.63 %, 35.11 %), and <em>R</em>RE<!--> <!--> consistently exceeded the <em>S</em>RE<!--> <!-->. Interaction terms significantly affected the <em>Rr</em> and <em>Sr</em> of litter and biochar (p &lt; 0.05) but did not have a significant impact on straw (p &gt; 0.05). Considering these findings and the cultivation characteristics of karst sloping farmland, and along with the availability and cost, straw is recommended for agricultural practices. This study provides a theoretical foundation and practical guidance for agronomic tillage practices and soil loss control in karst sloping farmlands.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"252 ","pages":"Article 106574"},"PeriodicalIF":6.1,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816969","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":"In-season temporal variability of soil carbon and nitrogen pools after half a century of a tillage and crop rotation gradient","authors":"Noelymar Gonzalez-Maldonado ,&nbsp;Leonardo Deiss ,&nbsp;Faheem Ali ,&nbsp;Steve W. Culman","doi":"10.1016/j.still.2025.106566","DOIUrl":"10.1016/j.still.2025.106566","url":null,"abstract":"<div><div>Reduced soil disturbance and diversified crop rotations are practices that can enhance organic matter and soil health. Understanding how these practices influence seasonal soil carbon (C) and nitrogen (N) variability during the growing season is critical for agroecosystem sustainability. We assessed temporal dynamics of soil C and N pools at six sampling dates over a maize (<em>Zea mays L.</em>) growing season, in a 55-year tillage and crop rotation experiment on silt loam and clay loam alfisols. Crop rotation had a more consistent effect than tillage on soil C and N pools (0–20 cm depth), with the most diverse rotation increasing soil organic carbon (SOC), permanganate oxidizable carbon (POXC), mineralizable carbon (Min C), total nitrogen (TN), autoclaved-citrate extractable (ACE) protein, inorganic N at both sites. No-Till increased C and N pools in the clay loam, but not in the silt loam soil. In general, fractions of C (POXC and Min C) and N (ACE protein and inorganic N) were more seasonally variable than total pools (SOC and TN). Despite temporal variation, tillage and rotation effects remained mostly consistent throughout the growing season, except for Min C which values decreased, and treatment differences diminished as the season progressed. Our findings suggest that 1) crop diversification with perennials enhances soil C and N regardless of soil type or tillage; 2) long-term No-Till has stronger effects in clay loam than silt loam soils, and 3) although C and N pools vary seasonally, long-term management effects persist throughout the growing season.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"252 ","pages":"Article 106566"},"PeriodicalIF":6.1,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817515","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":"Characterization of preferential flow and transport pathways under farmland with different land uses","authors":"Jiamin Ge ,&nbsp;Dongli She ,&nbsp;Xinni Ju ,&nbsp;Taohong Cao ,&nbsp;Yongqiu Xia","doi":"10.1016/j.still.2025.106573","DOIUrl":"10.1016/j.still.2025.106573","url":null,"abstract":"<div><div>Groundwater contamination in agriculturally intensive utilization areas is serious and widespread. Understanding the leaching of pollutants into groundwater is necessary, particularly the roles of preferential flow with macropores and solute transport in agricultural landscapes. However, limited studies focus on the quantitative effect of preferential flow on soil water and pollutants transport under different land uses in in-situ fields. This study quantified the process and paths of soil water and solute transport. This work also evaluated the impacts of three land uses (rice–wheat rotation (RW), vegetable (VG), and pear orchard (PO) fields) on the displacement of sodium bromide (Br⁻) and brilliant blue on a profile scale combined with field infiltration experiments. Results showed that in RW, VG, and PO fields, the stained area ratio decreased by 81.8 %, 82.6 %, and 86.7 % within 0–30 cm, respectively. Across the entire soil profile (0–100 cm), the majority of stained path width ratio concentrated at &lt; 1 cm, accounting for 53.8 %, 62.0 %, and 56.7 % in the RW, VG, and PO fields. In 0–20 cm soil layers, the proportion of stained path width ratio ranging from 1–8 cm relative to the entire profile was higher in RW and VG fields (51.2 % and 54.0 %, respectively) compared to the PO field (38.1 %). Moreover, the high macroporosity corresponds to the low stained area ratio. Further analysis revealed that water flow in the surface layers of all three land uses was primarily matrix flow. In contrast, macropore flow, predominantly mixed with low interaction, dominated in the subsurface layers (below 30 cm). Macropores were the main influencing factor of preferential flow. The mean residual concentration of Br⁻ ion in the profile followed the pattern RW (0.11∙10^–3 mol L^–1) &gt; PO (0^.08∙10^–3 mol L^–1) &gt; VG (0.04∙10^–3 mol L^–1). The RW field exhibited a deeper infiltration depth and faster movement speed. Consequently, the RW field with the characteristics of drying–wetting exhibited a more pronounced preferential flow than VG and PO in the profile, especially below the root zone (&gt; 40 cm). This study provides valuable insights into the migration pathways of nonpoint source and groundwater pollution in plain river network areas.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"252 ","pages":"Article 106573"},"PeriodicalIF":6.1,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816968","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":"Covariate selection approaches in spatial prediction of soil quality indices using machine learning models at the watershed scale, west of Iran","authors":"Marziyeh Zandi Baghche-Maryam ,&nbsp;Mohsen Sheklabadi ,&nbsp;Shamsollah Ayoubi","doi":"10.1016/j.still.2025.106571","DOIUrl":"10.1016/j.still.2025.106571","url":null,"abstract":"<div><div>Assessing soil quality indices (SQI’s) is a fundamental approach for agricultural and natural resources as well as sustainable management practices. This study addresses the digital mapping of SQI’s, with the objective of comparing the efficacy of four variable selection methods in Hamadan Province (west of Iran). The following methods were utilized to evaluate the predictive power of three machine learning (ML) models: principal component analysis (PCA), Boruta, recursive feature elimination (RFE), and random forest (RF). The ML models include artificial neural network (ANN), random forest (RF), and Cubist algorithm. Environmental variables were extracted from the digital elevation model (DEM) and Sentinel-2 image and employed in three scenarios: (i) topographic attributes, (ii) remote sensing data, and (iii) integration of scenarios (i) and (ii). A systematic and random grid sampling method was employed to collect 150 soil samples. Surface soil samples, were collected from 0–25 cm depth in agricultural and rangeland areas. The dominant soil groups were Xerorthents, Calcixerepts, and Haploxerepts. The samples were analyzed for physical and chemical properties, and the minimum data set (MDS) was determined by applying PCA. The indicators were scored using both linear and non-linear functions, and the SQI’s were calculated using the Additive Soil Quality Index (SQIa), the Weighted Soil Quality Index (SQIw), and the Nemoro Soil Quality Index (SQIn) methods. The best performances of the SQI’s were observed for SQIn derived from MDS and TDS using linear scoring. The results showed that scenario (iii) consistently yielded the most accurate predictions. The Boruta method and Cubist algorithm produced R² and RMSE values of 0.84 and 0.023, respectively, which were the most optimal in this context. The accuracy assessment demonstrated that the Boruta method and Cubist algorithm exhibited the highest accuracy in all three scenarios for predicting SQI. The uncertainty assessment revealed that the northwestern of the studied regions exhibited a higher degree of uncertainty, which can be attributed to the high diversity in topographic and soil attributes. The findings of this study offer a framework for developing spatial-based models to generate soil quality maps at a large scale, thereby facilitating informed decision-making for the further future land use plannings.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"252 ","pages":"Article 106571"},"PeriodicalIF":6.1,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817514","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":"Developing more effective phosphorus-loaded iron modified biochar fertilisers for improvement of peanut yield and regulation of soil phosphorus fractions","authors":"Junxiao Zhang ,&nbsp;Qi Wu ,&nbsp;Daocai Chi ,&nbsp;Guimin Xia ,&nbsp;Emmanuel Arthur","doi":"10.1016/j.still.2025.106572","DOIUrl":"10.1016/j.still.2025.106572","url":null,"abstract":"<div><div>Phosphorus-loaded iron-modified biochar (Fe-BP) can be used as farmlands' slow-release phosphorus (P) fertilizer. This study aimed to explore the effects of Fe-BP on soil P composition, phosphatase activity, peanut P accumulation, and P fertilizer utilization efficiency in sandy soi<u>l</u>. The two-year experiment was a randomized complete block design including no biochar and no P fertilizer (B0P0), no biochar and conventional phosphate fertilizer (CK) (B0P1, CK, P₂O₅ is 144 kg· ha⁻¹), biochar and CK (B1P1), iron-modified biochar (Fe-B) and CK (FeB-P1), P loaded Fe-B and CK (FeBP-P1), P loaded Fe-B and two third CK (FeBP-P2, P₂O₅ is 96 kg· ha⁻¹). It was found that Fe-B increased P accumulation, yield and P fertilizer utilization efficiency in peanuts. The physiological efficiency of P (PEP) of FeBP-P1 increased by 14.8 % compared with that of FeB-P1. During the fallow period, FeB-P1 decreased the soil available P content, while FeBP-P1 increased the soil available P content, and this effect lasted into the second year. Fe-B did not increase soil pH and did not significanlty affect acid phosphatase. FeBP-P2 increased NaHCO₃-Pi by 66 % and 49 %, respectively, compared to B0P0 and B0P1. This increase is mainly due to the slow release of phosphates carried by FeBP-P2. Overall, Fe-BP enhanced soil available P under reduced P fertilizer application, improving P use efficiency.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"252 ","pages":"Article 106572"},"PeriodicalIF":6.1,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143800254","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":"Dual film-controlled model urea improves summer maize yields, N fertilizer use efficiency and reduces greenhouse gas emissions","authors":"Yifeng Li ,&nbsp;Wenfei Yang ,&nbsp;Wanxin Wang ,&nbsp;Ningning Yu,&nbsp;Peng Liu,&nbsp;Bin Zhao,&nbsp;Jiwang Zhang,&nbsp;Baizhao Ren","doi":"10.1016/j.still.2025.106565","DOIUrl":"10.1016/j.still.2025.106565","url":null,"abstract":"<div><div>Controlled-release fertilizers are recognized for improving nitrogen efficiency, but they are significantly affected by environmental factors and often leading to suboptimal results. Nitrogen fertilizer synergists, due to their water solubility, exhibit limited persistence in the soil and cannot achieve the desired effect. Therefore, we incorporated nitrogen fertilizer synergists into the film of controlled-release fertilizer. Nitrogen fertilizer synergists were encapsulated within the film of the controlled-release fertilizer to achieved “dual film-controlled model”, which improved the performance of the controlled release fertilizer. A field experiment was conducted with five treatments: no N fertilizer (N0), controlled-release fertilizer (C210), controlled-release fertilizer combined with urease inhibitor (C210N), controlled-release fertilizer combined with nitrification inhibitor (C210D), controlled-release fertilizer combined with nitrification inhibitor and urease inhibitor (C210DN). Maize yield and economics, nitrogen use efficiency, gas emissions, global warming potential and apparent nitrogen losses were assessed. The results indicated that the application of this model regulates soil microbial community structure and functionality, thereby influencing soil nitrogen cycling processes and reduced global warming potential (GWP) and greenhouse gas intensity (GHGI). Additionally, C210DN increased NH₄⁺-N content in the 0–20 cm soil layer at the sixth leaf stage and the tasseling stage, while significantly decreasing NO₃^--N content. The dual film-controlled model improved nitrogen use efficiency by 7.9 %–17.7 %. Overall, the dual film-controlled urea model enhanced summer maize yield and nitrogen fertilizer use efficiency while mitigating environmental pollution and emissions.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"252 ","pages":"Article 106565"},"PeriodicalIF":6.1,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791955","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":"Effects of ultrasonic vibration-assisted cutting on tillage blade performance and soil fragmentation characteristics under different soil moisture contents","authors":"Jian Cheng ,&nbsp;Kan Zheng ,&nbsp;Junfang Xia ,&nbsp;Beihai Zhang ,&nbsp;Yang Ni ,&nbsp;Jun Ma","doi":"10.1016/j.still.2025.106575","DOIUrl":"10.1016/j.still.2025.106575","url":null,"abstract":"<div><div>In response to the challenge of high cutting resistance experienced by the blade during tillage operations, this study proposes a resistance reduction method based on ultrasonic vibration-assisted cutting. Five types of soil with different moisture contents were selected as the research objects, and a dynamic model of the blade and soil particles under ultrasonic vibration was constructed. The simulations employed the discrete element method (DEM) coupled with a contact model to calibrate soil models with different moisture contents. The cutting force and cutting energy in both the ultrasonic vibration-assisted cutting (UVAC) and conventional cutting (CC) modes were analyzed. Least significant difference and regression analysis were used to determine the differences between the two modes. Additionally, the force and velocity of soil particles under both cutting modes were examined to quantitatively and intuitively assess the fragmentation between particles. The results demonstrated that the simulation results were largely consistent with the bench experiment results. The simulation analysis effectively captured the trends in cutting force and cutting energy observed in the actual cutting process and revealed the microscopic changes in soil fragmentation. For all five moisture contents, the cutting force in both modes gradually increased with cutting depth, while the cutting force in UVAC mode was significantly reduced. As moisture content increased from 10 % to 30 %, the cutting energy for both modes decreased, with higher moisture content corresponding to lower energy requirements during cutting. Notably, the cutting energy in UVAC mode was reduced by more than 60 % across all moisture contents. Furthermore, UVAC mode enhanced the force and velocity of soil particles, facilitating the fragmentation of interparticle bonds. However, the electrical energy in UVAC mode was consistently higher than that in CC mode. In conclusion, this study demonstrates that using ultrasonic vibration-assisted blade for soil cutting effectively reduces cutting force and cutting energy while enhancing the fragmentation of soil particles. These findings provide a new research direction for the development of resistance reduction equipment in agricultural tillage operations.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"252 ","pages":"Article 106575"},"PeriodicalIF":6.1,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791956","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":"Effects of particle size fractions and clay content for determination of soil organic carbon and soil organic matter","authors":"Matthew Tiller ,&nbsp;Lucy Reading ,&nbsp;Les Dawes ,&nbsp;Marc Miska ,&nbsp;Prasanna Egodawatta","doi":"10.1016/j.still.2025.106568","DOIUrl":"10.1016/j.still.2025.106568","url":null,"abstract":"<div><div>Soil organic matter (SOM) and soil organic carbon (SOC) influence soil behaviour, quality, and applications. While conversion equations exist, the GlobalSoilMap Science Committee (2015) determined that no universal equation is viable due to regional soil variability. Instead, region-specific equations are required. This study presents SOM and SOC data from 75 sites for soils at 0–5 cm and 5–15 cm depth intervals, aligning with GlobalSoilMap specifications, allowing for global applicability of research findings. While this study develops region-specific SOM-SOC conversion equations for southeastern Queensland, the findings contribute to the broader understanding of how soil properties influence SOM-SOC relationships. The methods used, particularly clustered regression based on clay content and particle size, can be applied in other regions worldwide to refine soil carbon estimates in diverse landscapes. Regression analysis showed that the selected particle size fractions (&lt;2 mm vs. &lt;0.5 mm) had minimal effect on the dry combustion (DC) method but significantly influenced loss on ignition (LOI) results. A regression slope of 0.827 indicated that &lt; 2 mm samples yielded higher SOM values than &lt; 0.5 mm samples, introducing uncertainty in LOI-derived estimates. Clay content further impacted conversions: samples with &lt; 15 % clay produced robust equations with high coefficients of determination, whereas those with &gt; 15 % clay exhibited increased variance, lower slopes, and reduced accuracy, necessitating caution in their application. This research improves understanding of SOM-SOC relationships across key depth intervals and particle size fractions. It highlights the influence of clay content and particle size on LOI and DC methods, refining the accuracy of SOM and SOC estimation. These findings are valuable globally for soil science, agriculture, hydrology, and engineering, aiding more precise soil carbon assessments in various environmental and land management applications.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"252 ","pages":"Article 106568"},"PeriodicalIF":6.1,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791957","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":"Depth matters: The impact of vegetation clipping on phosphorus fractions across peatland depth profiles","authors":"Yuchen Suo ,&nbsp;Xin Guo ,&nbsp;Leming Ge ,&nbsp;Chenhao Cao ,&nbsp;Meng Wang","doi":"10.1016/j.still.2025.106564","DOIUrl":"10.1016/j.still.2025.106564","url":null,"abstract":"<div><div>The stability of carbon (C) stocks in peatlands is closely linked to phosphorus (P) bioavailability. Plant plays a crucial role in modulating P bioavailability. However, the mechanisms by which different plant functional types (PFTs; mainly <em>Sphagnum</em> moss, shrub, and graminoid) modulate P bioavailability in peatlands remain unknown, especially the vertical stratification related to plant belowground biomass distributions. In this study, we investigated the effects of PFT clipping on soil P bioavailability through a vegetation clipping manipulation, followed by the application of low molecular weight organic acids (LMWOAs) (azelaic, malonic, and muconic acids) and phosphatase enzymes (acid phosphatase, phosphodiesterase, and phytase). The results showed that LMWOAs are the key factors in promoting the concentration of soluble P in the soil, especially for organic P (P_o). Following PFT clipping, P bioavailability significantly decreased, except for graminoids, where clipping increased it. The relative abundance of P-solubilizing bacteria <em>Acinetobacter</em> and <em>Rhodanobacter</em> increased while soil pH decreased after graminoid clipping, which enhanced the desorption and dissolution of inorganic P and increased water-soluble orthophosphate concentration. Acid phosphatase activity decreased by ∼40 % after PFT clipping, indicating the reduction in the mineralization of P_o and the accumulation of potentially bioavailable P (i.e., enzyme-labile P_o), especially acid phosphatase and phosphodiesterase labile P_o. Furthermore, <em>Sphagnum</em> mosses, shrubs, and graminoids were the primary regulators of P bioavailability at depths of 0–10, 0–20, and 20–30 cm, respectively. Shift in vegetation composition driven by climate change and human activity may significantly influence P dynamics and the stability of C stock in peatlands, offering critical insights for balancing peatland conservation and agricultural utilization.</div></div>","PeriodicalId":49503,"journal":{"name":"Soil & Tillage Research","volume":"252 ","pages":"Article 106564"},"PeriodicalIF":6.1,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143791954","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}