Soil & Tillage Research最新文献

Integrated multispectral analysis of pyrogenic and total carbon in fire-managed cerrado soils 塞拉多火处理土壤中热原碳和总碳的综合多光谱分析

IF 6.8 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2026-01-30 DOI: 10.1016/j.still.2026.107062

Anna Carolina A.R. Zanatta , Eduardo G. Couto , Ana Maria X. dos Santos , Daniella C.S. Assis , Letícia G. Vogel , Matheus C. Cardoso , Bruno A. Bartsch , José A.M. Dematte

Spectroscopy offers a rapid and non-destructive approach for characterizing carbon in fire-affected soils, particularly in the Cerrado biome. Distinguishing total carbon (TC) from pyrogenic carbon (PC) remains challenging because both exhibit similar spectral signatures. This study evaluates the performance of Vis–NIR, MIR, and XRF spectroscopy for estimating TC and PC in soils under prescribed fire (PRF) and no-fire management (NPRF), as well as in associated charred materials.Vis–NIR provided the best estimates of TC in PRF soils, reflecting its sensitivity to fire-induced changes in organic matter. In NPRF soils, MIR showed the highest performance for TC due to its responsiveness to functional groups in more heterogeneous, minimally disturbed matrices. For PC, combining Vis–NIR and MIR improved predictions in both management systems, with higher accuracy in NPRF soils. XRF, although highly sensitive to fire-derived elements such as Fe, Si, and Ca, showed limited performance for PC in soils; however, it achieved the best results for PC estimation in charred residues. Vis–NIR was most effective for TC in the same material.The results indicate clear differences in TC and PC behavior across fire regimes. PRF soils showed lower TC and greater thermal alteration, whereas NPRF soils preserved higher TC with less aromatic enrichment. Although PC prediction remained moderate across models, the complementary information from Vis–NIR, MIR, and XRF improved the interpretation of the physicochemical factors controlling carbon variability. Refining multispectral calibration strategies will strengthen TC and PC discrimination and support carbon monitoring and fire-management planning in tropical ecosystems.

光谱学提供了一种快速和非破坏性的方法来表征受火灾影响的土壤中的碳，特别是在塞拉多生物群系中。区分总碳（TC）和热原碳（PC）仍然具有挑战性，因为两者具有相似的光谱特征。本研究评估了Vis-NIR， MIR和XRF光谱在规定火（PRF）和无火管理（NPRF）下土壤以及相关烧焦材料中估计TC和PC的性能。Vis-NIR提供了PRF土壤中TC的最佳估计，反映了其对火灾引起的有机质变化的敏感性。在NPRF土壤中，MIR对TC表现出最高的性能，这是因为它对异质性更强、干扰最小的基质中的官能团具有响应性。对于PC，结合Vis-NIR和MIR改进了两个管理系统的预测，在NPRF土壤中具有更高的准确性。XRF虽然对火源元素如Fe、Si和Ca高度敏感，但对土壤中的PC表现有限；但对于焦化残留物的PC估计效果最好。在相同的材料中，Vis-NIR对TC最有效。结果表明，在不同的火灾制度下，TC和PC行为存在明显差异。PRF土壤表现出较低的TC和较大的热蚀变，而NPRF土壤表现出较高的TC和较少的芳香富集。尽管各模型对碳变率的预测仍然较为温和，但来自Vis-NIR、MIR和XRF的补充信息改善了对控制碳变率的物理化学因素的解释。完善多光谱校准策略将加强热带生态系统中碳和PC的区分，并支持碳监测和火灾管理规划。

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引用次数: 0

Combining tillage and nitrogen practices to optimize soil nitrogen dynamics and wheat yield across various soil textures, using RZWQM2 以RZWQM2为研究对象，采用耕作与施氮相结合的方法优化不同质地土壤氮素动态和小麦产量

IF 6.8 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2026-01-29 DOI: 10.1016/j.still.2026.107093

Saadi Sattar Shahadha, Mawj R. Al-Hamdany

The optimal combination of tillage and nitrogen practices could be an effective strategy for improving crop yields and mitigating soil nitrogen loss. This study aimed to identify the optimal combination of field management practices for controlling soil nitrogen distribution and enhancing wheat yield across various soil textures in the semi-arid region of Iraq, using agricultural modeling. The Root Zone Water Quality Model (RZWQM2) was calibrated and validated using experimental field data from the 2023 and 2024 wheat-growing seasons. Various modeling scenarios were then created to evaluate and determine the optimal combination of tillage practices (deep tillage and shallow tillage) with nitrogen fertilization rates (100 and 250 kg N/ha) for sandy clay and silty clay soils. The model was successfully calibrated and validated with an accepted range of statistical indicators. Simulation results indicated that both soil textures presented comparable responses to all management practices. Simulation results indicated that, deep tillage practice reduced soil nitrate leaching and N₂O emissions by an average of 0.04 μg/cm² and 0.27 kg/ha, respectively, while increasing nitrate retention in the soil profile and wheat production by an average of 0.05 and 0.03 kg/ha, respectively, compared to shallow tillage. Applying 250 kg N/ha increased soil nitrate flux and N₂O emissions, particularly when combined with shallow tillage. Therefore, combining deep tillage with nitrogen application rates is the optimal field management approach and is suggested for both soil textures, as it minimizes soil nitrogen loss and enhances wheat productivity.

耕作与施氮的最佳组合可能是提高作物产量和减轻土壤氮流失的有效策略。本研究旨在利用农业模型，确定控制伊拉克半干旱区不同土壤质地土壤氮素分布和提高小麦产量的最佳田间管理措施组合。利用2023年和2024年小麦生长季的试验田数据对根区水质模型（RZWQM2）进行了标定和验证。然后创建各种模拟情景，以评估和确定砂质粘土和粉质粘土土壤的最佳耕作方式（深耕和浅耕）和施氮量（100和250 kg N/ha）的组合。该模型被成功地校准和验证了一个可接受的统计指标范围。模拟结果表明，两种土壤质地对所有管理措施的响应都具有可比性。模拟结果表明，与浅耕相比，深耕使土壤硝态氮淋溶和N2O排放分别平均减少0.04 μg/cm2和0.27 kg/ha，土壤剖面硝态氮滞留和小麦产量分别平均增加0.05和0.03 kg/ha。施用250 kg N/ha增加了土壤硝酸盐通量和N2O排放，特别是与浅耕结合使用时。因此，深耕与施氮量相结合是最佳的田间管理方法，适用于两种土壤质地，可最大限度地减少土壤氮素流失，提高小麦产量。

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引用次数: 0

Bio-matrix film mulching enhances Salvia miltiorrhiza quality by reprogramming the rhizosphere microbiota and activating the secondary metabolic pathway 生物基质地膜覆盖通过重新编程根际微生物群和激活次生代谢途径提高丹参品质

IF 6.8 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2026-01-29 DOI: 10.1016/j.still.2026.107094

Jin Xu , Yan Wang , Bing Zhao , Yi-Hao Liu , Mao-Qiang He , Yun-Fu Gu , Xiu-Mei Yu , Qiang Chen

Plastic-film mulching (PM) has been extensively employed in medicinal plant cultivation. However, plastic film residues result in severe soil pollution and further affect plant yields and quality. Bio-matrix film, made by mushroom residues and straw powders, has good potential as a sustainable alternative. Through the integration of multi-omics analyses, encompassing the rhizosphere soil microbiome, root transcriptome, and quantification of medicinal components, this study elucidated the mechanism by which bio-matrix film mulching (BM) enhances the quality of Salvia miltiorrhiza (S. miltiorrhiza), primarily by increasing the content of salvianolic acid B. The results showed that, during the root swelling period, compared with PM, BM significantly enriched Bradyrhizobium (normalized abundances +4.81 %) and Nitrospira C (+12.26 %), which drove soil nitrogen fixation (nifH/K) and nitrification (hao, nxrB), and increased NO₃^--N content (+50.09 %). Transcriptomic analysis revealed that BM induced the activation of the nitrogen metabolism pathway (NRT2, GDH, and GS), and the phenylpropanoid and tyrosine-derived pathway (TAT, RAS, and 4CL) of S. miltiorrhiza, thereby increasing the content of salvianolic acid B by 40.67 % (P < 0.001). During the harvest period, BM further enriched beneficial microbiota, including Lentzea (linked to enhanced C/N/P cycling) and arbuscular mycorrhizal fungi, which collectively improved root nutrient assimilation and reduced the loss rate of salvianolic acid B by 16.51 %. Hence, BM enhanced the quality of S. miltiorrhiza by “rhizosphere microbiota restructuring–soil nutrient activation–plant secondary metabolic network cascade response”. It offers an innovative solution with both ecological and economic benefits for cultivating medicinal plants.

地膜覆盖在药用植物栽培中得到了广泛的应用。然而，地膜残留造成了严重的土壤污染，进一步影响了植物的产量和品质。以蘑菇渣和秸秆粉为原料制备的生物基质膜具有良好的可持续发展潜力。本研究通过多组学分析，包括根际土壤微生物组、根转录组和药用成分定量分析，阐明了生物基质地膜（BM）提高丹参品质的机制，主要是通过提高丹参酚酸b的含量。结果表明，在根肿胀期，与PM相比，BM显著富集缓生根瘤菌（标准化丰度+4.81 %）和硝化螺菌C(+12.26 %)，促进土壤固氮（nifH/K）和硝化（hao, nxrB），提高NO3—N含量（+50.09 %）。转录组学分析显示，BM激活了丹参的氮代谢途径（NRT2、GDH和GS）以及苯丙氨酸和酪氨酸衍生途径（TAT、RAS和4CL），从而使丹参酚酸B的含量增加了40.67% % （P <； 0.001）。在收获期间，BM进一步丰富了有益菌群，包括Lentzea（与C/N/P循环增强有关）和丛枝菌根真菌，这些菌群共同促进了根系养分同化，使丹酚酸B的损失率降低了16.51% %。因此，BM通过“根际微生物群重构-土壤养分活化-植物次生代谢网络级联响应”提高了丹参品质。为药用植物的培育提供了一种兼具生态效益和经济效益的创新解决方案。

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引用次数: 0

Plant and microbial pathways driving soil carbon sequestration in dryland leguminous shrublands 植物和微生物途径驱动旱地豆科灌丛土壤固碳

IF 6.8 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2026-01-28 DOI: 10.1016/j.still.2026.107096

Zi-Qiang Yuan , Chao Fang , Xin Song , Yi Wu , Feng Zhang , Xiang-Wen Fang , Guang-Qian Yao , Kevin Van Sundert , Feng-Min Li

The establishment of leguminous shrubs has become a key strategy for dryland restoration, offering substantial potential to enhance soil organic carbon (SOC) sequestration. However, the mechanisms governing SOC stabilization in these systems remain insufficiently understood. Here, we investigated 30 Caragana korshinskii shrubland sites distributed across north-facing (NFS) and south-facing slopes (SFS) to identify the dominant drivers of SOC accrual within the 0–40 cm soil profile relative to adjacent croplands. Across both slope aspects, NFS shrublands exhibited a 77 % increase in particulate organic carbon (POC) and a 28 % increase in mineral-associated organic carbon (MAOC), whereas SFS shrublands showed a markedly larger enhancement in POC (257 %) but a comparable increase in MAOC (22 %). Shrubland soils accumulated substantially greater quantities of lignin phenols and microbial residue carbon (MRC), increasing by 43 % and 49 % on NFS and by 183 % and 75 % on SFS, respectively, compared with croplands. Isotopic signatures (δ¹⁵N and δ¹³C) were consistently more depleted in shrublands across both slope aspects, indicating shifts in organic matter sources and transformation pathways. Structural equation modelling revealed that C. korshinskii establishment enhanced both POC and MAOC pools by increasing root biomass and soil total nitrogen, thereby stimulating microbial activity and the accumulation of lignin phenols and MRC. Slope aspect exerted an indirect influence on POC and MAOC through its effects on root biomass, soil moisture, and mineral properties. Our findings provide direct evidence that leguminous shrubs promote SOC sequestration through the coordinated action of plant and microbial pathways, highlighting a key mechanism by which topography modulates the formation and stabilization of SOC under changing land use regimes in dryland ecosystems.

豆科灌木的建立已成为旱地恢复的关键策略，具有增强土壤有机碳（SOC）固存的巨大潜力。然而，在这些系统中控制SOC稳定的机制仍然没有得到充分的了解。本研究以30个柠条灌木林地为研究对象，分布在朝北（NFS）和朝南（SFS）的山坡上，以确定0-40 cm土壤剖面相对于邻近农田土壤有机碳积累的主要驱动因素。在两个坡面，NFS灌丛地颗粒有机碳（POC）增加了77 %，矿物相关有机碳（MAOC）增加了28 %，而SFS灌丛地POC（257 %）的增加幅度更大，而MAOC的增加幅度也相当（22 %）。灌木林土壤的木质素酚类物质和微生物残碳（MRC）积累量显著高于农田，在NFS上分别增加了43% %和49% %，在SFS上分别增加了183 %和75% %。同位素特征（δ¹5 N和δ¹³C）在两个坡面的灌丛中一直更加枯竭，表明有机质来源和转化途径的变化。结构方程模型表明，柠条的建立通过增加根系生物量和土壤全氮来增强POC和MAOC库，从而促进微生物活性和木质素酚类物质和MRC的积累。坡向通过对根系生物量、土壤水分和矿物性质的影响间接影响POC和MAOC。本研究结果为豆科灌木通过植物和微生物途径的协同作用促进有机碳的吸收提供了直接证据，揭示了在土地利用制度变化下，地形调节旱地生态系统有机碳形成和稳定的关键机制。

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引用次数: 0

Depth-stratified isotopic and molecular signatures reveal decoupled soil organic matter dynamics following grassland-to-cropland conversion 深度分层同位素和分子特征揭示了草地向农田转化后土壤有机质动力学解耦

IF 6.8 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2026-01-28 DOI: 10.1016/j.still.2026.107095

Yuxin Yan, Yumei Peng, Jia Shi, Chunpeng Huo, Xiang Wang

Land-use transitions (LUTs) from native grasslands to croplands induce duration-dependent destabilization in soil organic carbon (SOC) dynamics, with subsoil pools (80–100 cm) exhibiting disproportionately high vulnerability to prolonged agricultural management. This study assessed the time-dependent impacts of LUTs on SOC dynamics, by integrating stable isotopic (δ¹³C and δ¹⁵N), stoichiometric (C/N), and molecular (lignin phenols) indicators across topsoil (0–20 cm) and subsoil layers. Our results revealed bulk soils exhibited significant enrichment in δ¹³C (Δ=1.53–2.10 ‰) and δ¹⁵N (Δ=0.03–2.91 ‰) following conversion, with mineral-associated organic matter (MAOM) retaining isotopic signatures closely aligned with bulk soil. Lignin content in topsoil decreased by 18.1 % after initial cultivation but recovered under long-term management, while subsoils showed progressive lignin accumulation (+160–200 %). Compared to native systems, managed croplands exhibited a tendency toward isotopic and functional decoupling between particulate organic matter (POM) and MAOM fractions, alongside a breakdown of δ¹³C-δ¹⁵N correlations, indicative of a shift in underlying biogeochemical cycling. These changes were most pronounced in subsoils, challenging the assumption of deep SOC stability. Overall, our findings provide critical insights into the mechanisms underlying SOM persistence and vulnerability under land-use transition and highlight the need for depth- and fraction-specific assessments in managed ecosystems.

从天然草地到农田的土地利用过渡（LUTs）会导致土壤有机碳（SOC）动态的持续不稳定，土壤底土库（80-100 cm）对长期农业管理表现出不成比例的高脆弱性。本研究通过整合表层土壤（0-20 cm）和下层土壤的稳定同位素（δ13C和δ15N）、化学计量（C/N）和分子（木质素酚）指标，评估了LUTs对有机碳动态的时间依赖影响。结果表明，转化后块状土壤Δ 13c （Δ=1.53 ~ 2.10 ‰）和Δ 15n （Δ=0.03 ~ 2.91 ‰）显著富集，矿物伴生有机质（MAOM）同位素特征与块状土壤密切一致。表层土壤木质素含量在初始栽培后下降18.1 %，但在长期管理下恢复，而底土木质素含量逐渐积累（+ 160-200 %）。与自然系统相比，管理农田颗粒有机质（POM）和MAOM组分之间呈现出同位素和功能解耦的趋势，同时δ13C-δ15N相关性被破坏，表明潜在的生物地球化学循环发生了变化。这些变化在底土中最为明显，对深层有机碳稳定性的假设提出了挑战。总体而言，我们的研究结果为土地利用转型下SOM持续存在和脆弱性的机制提供了重要见解，并强调了对受管理生态系统进行深度和部分特定评估的必要性。

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引用次数: 0

Straw return modulates surface energy balance and soil hydrothermal dynamics during freeze-thaw period 秸秆还田调节冻融期地表能量平衡和土壤热液动态

IF 6.8 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2026-01-26 DOI: 10.1016/j.still.2026.107083

Wanning Wang , Hexiang Zheng , Xingwang Wang , Delong Tian , Qian Wang , Zailin Huo

Straw return modifies topsoil properties that are crucial for understanding soil-atmosphere interactions and their impact on soil hydrothermal conditions in seasonally frozen areas. However, the effects of uniformly returning crushed straw (3–5 cm in length at 1.6–1.8 kg·m⁻²) on the surface energy balance (SEB) and soil water-heat dynamics during the freeze-thaw period remain inadequately quantified. We conducted a two-year field experiment in a cold-arid region of Northwest China, employing a Bowen ratio energy balance system (BREBS) to monitor SEB components (Rn, Gs, H, LE), alongside soil temperature and moisture. Results demonstrated that straw return (ST) obviously altered SEB components during freeze-thaw periods. Specifically, over the two-year period, seasonal variations showed that ST reduced Rn by 8.6–9.1 W·m⁻² relative to NT, decreased Gs by 0.24 W·m⁻², lowered LE by 49 %, while increased the Bowen ratio by 48 % and H. During the thawing period, diurnal variations showed LE decreasing by 36 % and H increasing by 11 % under ST compared to NT. Furthermore, ST delayed topsoil thawing by 3–7 days, increased unfrozen water content (UWC) by 2.9–4.3 %, reduced freezing depth, and stabilized deep-layer soil temperature and moisture. These findings endorse straw return as a viable strategy for conserving soil moisture, mitigating frost damage, and optimizing spring sowing schedules in arid cold regions.’

秸秆还田改变了表层土壤的性质，这些性质对于了解季节性冻结地区土壤-大气相互作用及其对土壤热液条件的影响至关重要。然而，在冻融期，秸秆碎料（长度为3-5 cm，长度为1.6-1.8 kg·m−2）均匀回用对地表能量平衡（SEB）和土壤水热动态的影响仍未得到充分量化。在中国西北寒冷干旱区进行了为期两年的田间试验，采用博温比能量平衡系统（BREBS）监测土壤温度和湿度，同时监测土壤SEB组分（Rn、Gs、H、LE）。结果表明，秸秆还田明显改变了冻融期土壤SEB组分。2年的季节变化表明，与NT相比，ST降低了8.6 ~ 9.1 W·m−2，降低了0.24 W·m−2，降低了49 %，增加了48 %和H。在融化期间，日变化表明，与NT相比，ST下LE减少了36 %，H增加了11 %。此外，ST使表土融化延迟了3 ~ 7天，使未冻水含量（UWC）增加了2.9 ~ 4.3 %，降低了冻结深度。稳定了深层土壤的温度和湿度。这些发现支持秸秆还田是在干旱寒冷地区保持土壤水分、减轻霜冻损害和优化春播时间表的可行策略。”

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引用次数: 0

Assessing soil organic carbon responses to tillage and extreme weather in Pakistan using the CQESTR model 利用CQESTR模型评估巴基斯坦土壤有机碳对耕作和极端天气的响应

IF 6.8 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2026-01-24 DOI: 10.1016/j.still.2025.107047

Adnan Zahid , Hero T. Gollany , Sajid Ali , Mukhtar Ahmad , Nadeem Iqbal

Intensive tillage has depleted soil organic carbon (SOC) and threatened the sustainability of the rice-wheat cropping system of South Asia. This study assessed SOC dynamics using the CQESTR model, a process-based model, to identify the best management option under five tillage and extreme weather scenarios: (i) conventional tillage (S-1), (ii) residue incorporation (S-2), (iii) direct seeding with straws removed (S-3), (iv) direct seeding with rice straw returned while wheat straw removed (S-4), and (v) conservation tillage with both rice and wheat residues retained (S-5). Five yield scenarios (i.e., current yield, 5 or 10 % decrease/increase) were simulated with three extreme weather scenarios. The CQESTR-simulated and the measured values were strongly correlated (r = 0.991, p < 0.001) for the 0–45 cm soil depth across different tillage scenarios. Nash–Sutcliffe efficiency (NSE) of 0.99, a root mean square error (RMSE) of 0.36, and a mean square deviation (MSD) of 0.13 confirmed simulated and measured values were well correlated. Among the tillage scenarios, the highest SOC gain of 1.84 Mg ha-¹ year-¹ was recorded under the S-5 scenario, followed by 0.24, 0.21, and 0.21 Mg ha-¹ year-¹ under S-4, S-3, and S-2, respectively. In contrast, conventional tillage (S-1) was predicted to lose 0.49 Mg ha⁻¹ under predictive periods of 2019–2038. The conservation tillage with residues retained (S-5) sequestered SOC, while S-1 depleted SOC across all scenarios. The S-5 had a maximum SOC increase of 3.0 Mg ha⁻¹ at 110 % yield and 2.6 Mg ha⁻¹ with baseline weather under RCP 4.5 during 20 predictive years. Therefore, continuous conservation tillage with total residue returned (S-5) can potentially reduce the effects of extreme weather while increasing SOC and enhancing the region's sustainability.

集约耕作使南亚地区土壤有机碳（SOC）耗竭，威胁到稻麦种植系统的可持续性。本研究利用基于过程的CQESTR模型评估了土壤有机碳动态，以确定五种耕作和极端天气情景下的最佳管理方案：(i)传统耕作（S-1），（ii）秸秆混交（S-2），（iii）秸秆秸秆直接播种（S-3），（iv）秸秆秸秆直接播种，秸秆秸秆去除（S-4），以及(v)保留水稻和小麦秸秆的保护性耕作（S-5）。在三种极端天气情景下，模拟了五种产量情景（即当前产量、5%或10% %减少/增加）。在0 ~ 45 cm不同耕作方式下，cqestr模拟值与实测值呈强相关（r = 0.991,p <； 0.001）。Nash-Sutcliffe效率（NSE）为0.99，均方根误差（RMSE）为0.36，均方偏差（MSD）为0.13，证实模拟值与实测值具有良好的相关性。在不同耕作方式下，S-5方案土壤有机碳收益最高，为1.84 Mg ha-¹ 年-¹ ，S-4、S-3和S-2分别为0.24、0.21和0.21 Mg ha-¹ 年-¹ 。相比之下，在2019-2038年的预测期内，常规耕作（S-1）预计损失0.49 Mg ha -1。保留残留物（S-5）的保护性耕作吸收了有机碳，而保留残留物（S-1）的保护性耕作消耗了有机碳。在20个预测年期间，S-5在产量为110 %时土壤有机碳最大增幅为3.0 Mg ha - 1，在RCP为4.5的基线条件下土壤有机碳最大增幅为2.6 Mg ha - 1。因此，全残还田（S-5）连续保护性耕作可以减少极端天气的影响，同时增加土壤有机碳，增强区域的可持续性。

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引用次数: 0

Greenhouse gas emissions in response to tillage and crop phase in a four-year crop rotation 温室气体排放对四年轮作中耕作和作物阶段的响应

IF 6.8 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2026-01-24 DOI: 10.1016/j.still.2026.107089

Upendra M. Sainju , William B. Stevens , Jalal D. Jabro , William M. Iversen , Brett L. Allen , Sikiru Y. Alasinrin

Cropping systems can affect greenhouse gas (GHG) emissions due to variations in farm operations, root respiration, and soil organic matter mineralization that need further exploration. We examined the effect of tillage (conventional till [CT] and no-till [NT]) and crop phases (sugarbeet [Beta vulgaris L.] and corn [Zea mays L.]) on CO₂, N₂O, and CH₄ fluxes and GHG balance (GHGB or sum of CO₂ equivalents of all GHGs) in an irrigated barley (Hordeum vulgare L.)-sugarbeet-corn-soybean (Glycine max L.) rotation from 2016 to 2020 in the US northern Great Plains. A static chamber method was used to measure GHG fluxes at 3–30 d intervals, depending on crop performance and soil environment, throughout the year. While CO₂ peak fluxes occurred mostly during the crop growing season, N₂O peak fluxes occurred throughout the year. The CH₄ flux was minimal, except for some peaks in October 2017 and January and April 2019. Cumulative CO₂ flux from May to April and GHGB were 26–44 % greater for CT with sugarbeet than NT with sugarbeet or corn in 2016–2017 and 24–41 % greater for NT with sugarbeet than CT with corn in 2018–2019 and 2019–2020. Cumulative N₂O flux was 70–244 % greater for CT with sugarbeet than NT with sugarbeet in 2016–2017 and 2019–2020 and 38–73 % greater for NT with sugarbeet than other treatments in 2018–2019. Cumulative CH₄ flux did not vary among treatments in any year. The GHG emissions can be reduced by using CT with corn and NT with corn and sugarbeet compared with CT with sugarbeet during the dry year and using CT with corn compared with other treatments during the wet year in the barley-sugarbeet-corn-soybean rotation under sandy loam soils of the US northern Great Plains, indicating that treatments effect on reducing GHG emissions varied with climatic conditions.

由于农场经营、根系呼吸和土壤有机质矿化的变化，种植制度会影响温室气体（GHG）排放，这些需要进一步探索。研究了2016 - 2020年美国北部大平原灌溉大麦(Hordeum vulgare L.)-甜菜-玉米-大豆（Glycine max L.）轮作中耕作方式（常规耕作[CT]和免耕[NT]）和作物阶段（甜菜[Beta vulgaris L.]和玉米[Zea mays L.]）对CO2、N2O和CH4通量和温室气体平衡（GHGB或所有温室气体CO2当量总和）的影响。根据作物性能和土壤环境的不同，采用静态室法在全年每隔3-30 d测量温室气体通量。CO2峰值通量主要出现在作物生长季节，而N2O峰值通量出现在全年。除2017年10月和2019年1月和4月出现峰值外，CH4通量最小。2016-2017年5 - 4月累积CO2通量和温室气体排放总量，种植甜菜的稻田比种植甜菜或玉米的稻田高26-44 %，2018-2019年和2019-2020年种植甜菜的稻田比种植玉米的稻田高24-41 %。在2016-2017年和2019-2020年期间，含糖甜菜的CT处理的累积N2O通量比含糖甜菜的NT处理高70-244 %，在2018-2019年期间，含糖甜菜的NT处理的累积N2O通量比其他处理高38-73 %。各处理间的累积CH4通量无显著差异。在美国北部大平原砂质壤土下大麦-甜菜-玉米-大豆轮作中，旱年与玉米联合使用CT、玉米与甜菜联合使用NT比旱年与玉米与甜菜联合使用NT更能减少温室气体排放，旱年与玉米联合使用CT比其他处理更能减少温室气体排放，说明不同气候条件下不同处理的温室气体减排效果不同。

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引用次数: 0

Coupling root morphology and soil mechanics: The R–S MAFI model for predicting root–soil interactions 根系形态与土壤力学的耦合：预测根系-土壤相互作用的R-S MAFI模型

IF 6.8 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2026-01-23 DOI: 10.1016/j.still.2026.107092

He Zheng , Dongfang Li , Lei Wei , Min He , Hao Sun , Lin Zhu , Maohua Xiao

Barnyardgrass roots markedly alter soil mechanical behavior and pose significant challenges to rotary tillage and mechanical weeding in paddy fields. However, most existing studies rely on 2D or soilless observations that cannot represent real three-dimensional (3D) fibrous root architecture, and they rarely consider the bidirectional mechanical feedback between root growth and soil shear strength. Consequently, the spatiotemporal evolution of barnyardgrass root systems and their reinforcement effect on soil remains poorly quantified. To address these deficiencies, this study develops a Root–Structure–Mechanics–Adaptive Fractal Integration (R–S MAFI) model that integrates 3D root morphological development with soil porosity–dependent mechanical feedback. The model facilitates dynamic simulation of root architecture (e.g., length and distribution depth) for a period of 0–32 days, and the obtained parameters are highly consistent with experimental measurements, validating the model's geometric reliability. Direct shear tests and simulation results further demonstrated that roots considerably enhance soil shear strength: at 32 days, the predicted shear strength of the root–soil composite was 39.5 % higher than that of bare soil, closely matching the experimentally measured improvement of 36.2 %. The shear strength distribution over time and soil depth indicated that the most significant reinforcement occurred in shallow layers (30–60 mm), with weaker reinforcement observed at greater depths (>90 mm). The R–S MAFI model provides a robust tool for studying root–soil interactions in crops and weeds and offers theoretical support for the optimization of rotary tillage, mechanical weeding, and soil amendment practices.

稗草根系显著改变了土壤的力学行为，对水田旋耕和机械除草提出了重大挑战。然而，现有的研究大多依赖于二维或无土观测，不能代表真实的三维（3D）纤维根结构，并且很少考虑根生长与土壤抗剪强度之间的双向力学反馈。因此，对禾草根系的时空演变及其对土壤的加固作用的定量研究仍然很缺乏。为了解决这些不足，本研究开发了一个根系结构-力学-自适应分形积分（R-S MAFI）模型，该模型将三维根系形态发育与土壤孔隙度依赖的力学反馈相结合。该模型可对0 ~ 32天的根系构型（如长度、分布深度等）进行动态模拟，得到的参数与实验测量值高度吻合，验证了模型的几何可靠性。直接剪切试验和模拟结果进一步表明，根系显著提高了土壤抗剪强度：在32 d时，根土复合材料的预测抗剪强度比裸土高39.5% %，与实验测量的36.2% %非常接近。抗剪强度随时间和土层深度的分布表明，浅层（30 ~ 60 mm）加固效果最显著，深度越深（90 mm）加固效果越弱。R-S MAFI模型为研究作物和杂草的根土相互作用提供了强有力的工具，并为轮作、机械除草和土壤改良措施的优化提供了理论支持。

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引用次数: 0

Evaluation of phosphate adsorption and desorption on Andosols using a stirred flow chamber 用搅拌流室评价磷酸盐在安多溶胶上的吸附和解吸

IF 6.8 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2026-01-23 DOI: 10.1016/j.still.2026.107090

Yuika Ochi, Takehide Hama

Andosols are soils derived from volcanic ash minerals and contain significant amounts of active aluminum and iron, which strongly adsorb phosphorus (P). However, the excessive P accumulation can lead to water pollution. Reaction time can affect the adsorption and desorption dynamics of P, and therefore, it is a key factor to understand P cycling. Nevertheless, the kinetics of phosphate adsorption/desorption in Andosols is not well understood, and the relationship between phosphate desorption amount and the oxidation-reduction potential (ORP), which is the main factor, is also unclear. Therefore, in this study, the adsorption/desorption behavior of phosphate under oxidizing and reducing conditions was investigated using a stirred-flow chamber test, which is suitable for evaluating the reaction kinetics and desorption process. The results indicated that phosphate strongly adsorbed under oxidative conditions, with the maximum adsorption correlating to the active aluminum levels. Further, phosphate desorbed as Fe(Ⅲ) reduced under reducing conditions and formed soluble Fe(Ⅱ). The desorption process could be described by a Gompertz-type model, which showed an exponential increase in phosphate/Fe(Ⅱ) desorption with decreasing pe + pH values. The maximum phosphate desorption showed strong correlations with Fe-P bond and active iron content, whereas the maximum Fe(II) desorption was statistically correlated with active aluminum and iron contents. Based on the established relationship between pe + pH and phosphate/Fe(Ⅱ) desorption, the maximum loss of phosphate/Fe(II) can be calculated by measuring the temporal change in pe + pH on farmland. This study provides understanding the phosphate adsorption/desorption kinetics in Andosols and contribute to preventing eutrophication.

安多土是来源于火山灰矿物的土壤，含有大量的活性铝和铁，它们对磷有很强的吸附作用。然而，过量的磷积累会导致水体污染。反应时间会影响磷的吸附和解吸动力学，因此是了解磷循环的关键因素。然而，磷酸盐在安多索溶胶中的吸附/解吸动力学尚不清楚，磷酸盐解吸量与氧化还原电位（ORP）之间的关系也不清楚，而氧化还原电位是主要因素。因此，在本研究中，采用搅拌流室试验研究了磷酸盐在氧化和还原条件下的吸附/解吸行为，该试验适合于评价反应动力学和解吸过程。结果表明，磷酸盐在氧化条件下具有较强的吸附作用，其最大吸附量与活性铝水平有关。此外，磷酸盐解吸为Fe（Ⅲ），在还原条件下还原并形成可溶性Fe（Ⅱ）。解吸过程可以用gompertz模型来描述，随着pe + pH值的降低，磷酸盐/Fe（Ⅱ）的解吸呈指数增长。磷酸盐最大解吸量与Fe- p键和活性铁含量呈显著相关，而Fe（II）最大解吸量与活性铝和活性铁含量呈显著相关。根据已建立的pe + pH与磷/铁（Ⅱ）解吸的关系，通过测定农田pe + pH的时间变化，可以计算出磷/铁（II）的最大损失。该研究有助于了解磷酸盐在安多酚中的吸附/解吸动力学，并有助于防止富营养化。

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引用次数: 0