Geoderma最新文献_第8页

Commentary: Structural equation models and causal claims in soil science and biogeochemistry – An equation-free “how to” 评论：土壤科学和生物地球化学中的结构方程模型和因果断言——一个没有方程的“如何”

IF 6.6 1区农林科学 Q1 SOIL SCIENCE

Geoderma

Pub Date : 2026-02-01 DOI: 10.1016/j.geoderma.2026.117702

Jordon Wade , Teal M. Potter , Andrew J. Margenot

Structural equation modeling (SEM) is a set of approaches that have seen exponential usage in the soil sciences as well as the related fields of agriculture and biogeochemistry. When correctly used and interpreted, SEM can be a powerful and flexible tool to test complex hypotheses on causality. However, the recent explosion of SEM usage in the soil sciences facilitated by user-friendly statistical programs has not been fully met by statistical expertise of users, reviewers and editors, ultimately leading to widespread contamination of the literature with inappropriate modeling and inflated or unfounded causal claims. The rise of such “SEM slop” poses a serious risk of an unreliable knowledge base and also undermines efforts and standards on what constitutes causality in the soil sciences. To address this, we diagnose major pitfalls in SEM, with an eye towards considerations specific to soil sciences, categorizable as three types: (1) Causal claims, including not satisfying causal criteria, lack of justified a priori models, not considering counterfactuals, and unqualified causal language; (2) Experimental design, including use in randomized complete block designs without complete pooling or multi-level models, inappropriate data type (e.g., ontological misalignment), and insufficient sample size; and, (3) Assessing the model, including incomplete or inappropriate model evaluation, non-qualified use of modification indices, and lack of robustness tests. There is a dual imperative for users as well as reviewers and editors to better implement and evaluate SEMs and claims of causality made with SEMs. To support this, we offer best practices and practical considerations on these three major pitfalls. These best practices will help SEM be appropriately employed as a powerful, nuanced statistical tool that benefits the soil science community.

结构方程模型（SEM）是一组在土壤科学以及农业和生物地球化学等相关领域得到指数级应用的方法。当正确使用和解释时，扫描电镜可以成为一个强大而灵活的工具来测试复杂的因果关系假设。然而，最近在用户友好的统计程序的推动下，土壤科学中SEM的使用爆炸式增长，并没有完全满足用户、审稿人和编辑的统计专业知识，最终导致文献被不适当的建模和夸大或毫无根据的因果关系所污染。这种“SEM斜坡”的兴起带来了知识库不可靠的严重风险，也破坏了土壤科学中因果关系构成的努力和标准。为了解决这个问题，我们诊断了SEM的主要缺陷，着眼于土壤科学的具体考虑，可分为三种类型：(1)因果主张，包括不满足因果标准，缺乏合理的先验模型，不考虑反事实和不合格的因果语言；(2)实验设计，包括在没有完全池化或多级模型的随机完全块设计中使用，不适当的数据类型（例如，本体论偏差）和样本量不足；(3)评估模型，包括模型评估不完整或不适当，修正指标使用不合格，缺乏稳健性检验。对于用户、审稿人和编辑来说，更好地实现和评估sem以及通过sem提出的因果关系主张具有双重必要性。为了支持这一点，我们提供了关于这三个主要缺陷的最佳实践和实际考虑。这些最佳实践将有助于SEM作为一种强大的、细致入微的统计工具被适当地使用，从而使土壤科学界受益。

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引用次数: 0

Carbon-phosphorus stoichiometric imbalance induced by manure amendment enhances microbial phosphorus mobilization and crop phosphorus uptake 肥料改良引起的碳磷化学计量失衡促进了微生物对磷的动员和作物对磷的吸收

IF 6.6 1区农林科学 Q1 SOIL SCIENCE

Geoderma

Pub Date : 2026-02-01 DOI: 10.1016/j.geoderma.2026.117711

Wangzun Chen , Yanlong Li , Yi Peng , Letian Wang , Gu Feng

Fertilization alters soil stoichiometric ratios, shaping microbial processes and phosphorus (P) dynamics, yet the underlying mechanisms remain poorly understood. Here, we conducted a three-year maize field experiment on the North China Plain, to test how P-based manure amendments modified soil C:P ratio, intensified microbially mediated soil P mobilization and turnover processes, and improved crop P uptake and yield. There were four treatments as follows: P0, no P fertilizer; P1, 39.27 kg ha⁻¹ of chemical P; LCP, with a total P input of 39.27 kg P ha⁻¹, input 0.76 t ha⁻¹ manure C; and HCP, with a total P input of 39.27 kg P ha⁻¹, input 1.53 t ha⁻¹ manure C. Our results suggested that manure C inputs significantly increased the content of soil dissolved organic carbon (DOC) and induced a shift in microbial community composition from oligotrophic (Acidobacteria) to copiotrophic taxa (Proteobacteria, Bacteroidetes, Myxococcota), accompanied by increased microbial biomass P. Manure amendment significantly raised the soil C:P ratio, but the microbial C:P ratio remained relatively stable across treatments. The induced C:P imbalance intensified microbial P limitation, exerting selective pressure on soil microbes preferential investment in P mobilization. Through the coordinated regulation of microbial community composition and function, manure amendment enhanced the bioavailable P pool and increased plant P acquisition. By increasing soil C:P ratios relative to full chemical fertilization, P-based manure amendment increased maize yield by 12%, improved P fertilizer recovery efficiency from 81.34% to 97.06%, enhanced P fertilizer utilization efficiency from 22.01% to 36.69%, and reduced soil P accumulation from 7.35 to 1.15 kg P ha⁻¹ year⁻¹. These findings suggest that manure-induced stoichiometric imbalance triggers a priming effect on indigenous microbial P mobilization, providing an ecologically intensive pathway to enhance fertilizer P use efficiency, reduce environmental P loading, and improve crop productivity.

施肥改变土壤化学计量比，塑造微生物过程和磷(P)动态，但潜在的机制仍然知之甚少。本研究在华北平原进行了为期3年的玉米田试验，研究了磷基肥料改剂剂对土壤碳磷比的影响，增强了微生物介导的土壤磷的动员和周转过程，提高了作物对磷的吸收和产量。4个处理分别为：P0，不施磷肥；P1, 39.27 kg ha - 1化学P；LCP，总磷投入量为39.27 kg P ha−1，粪肥C投入量为0.76 t ha−1；结果表明，有机肥C显著提高了土壤溶解有机碳（DOC）含量，并导致微生物群落组成由贫营养（酸杆菌）向富营养（变形菌门、拟杆菌门、粘球菌门）转变，同时显著提高了微生物生物量P。但各处理间微生物C:P比值保持相对稳定。碳磷失衡加剧了微生物对磷的限制，对土壤微生物优先投入磷动员施加了选择压力。通过对微生物群落组成和功能的协调调节，肥料改良增加了生物有效磷库，增加了植物磷的获取。通过提高土壤C:P比，磷肥改良使玉米产量提高了12%，磷肥回收率从81.34%提高到97.06%，磷肥利用率从22.01%提高到36.69%，土壤磷素积累量从7.35 kg P ha - 1年- 1减少到1.15 kg P ha - 1年- 1。这些结果表明，粪便诱导的化学计量失衡触发了本地微生物磷动员的启动效应，为提高肥料磷利用效率、减少环境磷负荷和提高作物生产力提供了生态集约途径。

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引用次数: 0

Pasture management in Ferralsols drives mineral-associated organic matter storage, exceeding native soil carbon stocks and enhancing cation exchange capacity feralsols的牧场管理促进了矿物相关有机质的储存，超过了原生土壤碳储量，并增强了阳离子交换能力

IF 6.6 1区农林科学 Q1 SOIL SCIENCE

Geoderma

Pub Date : 2026-02-01 DOI: 10.1016/j.geoderma.2026.117678

Lucas Raimundo Bento , Ladislau Martin-Neto , João Vitor dos Santos , Vitor Silveira Freitas , José Ricardo Macedo Pezzopane , Alberto Carlos de Campos Bernardi , Patrícia Perondi Anchão Oliveira , Steffen A. Schweizer

Pasture management is pivotal for enhancing soil organic carbon (SOC) storage in tropical grasslands, yet SOC recovery is often considered merely as the replenishment of historical losses following land-use change. It remains unclear whether managed Ferralsols can surpass the SOC stocks of native vegetation (NV) and which mechanisms drive such gains. We evaluated SOC pools, chemical composition, and nutrient-holding capacity after 24 years under unmanaged degraded pasture (DP) and fertilized managed pasture (MP), relative to NV. SOC storage in these systems was primarily mediated by the mineral-associated organic matter (MAOM) pool. Compared to NV, DP soils exhibited reduced MAOM stocks (119 vs. 92 Mg C ha⁻¹), whereas MP soils stored 148 Mg C ha⁻¹. In DP, soil acidity, low nutrient availability, and poor forage inputs induced microbial stress (as revealed by phospholipid fatty acid profiles), likely constraining MAOM formation and yielding MAOM enriched in carbohydrates with fewer carbonyl groups. In contrast, liming and fertilization in MP alleviated the Ferralsol’s low pH and nutrient deficiencies, enhancing forage yields and reducing microbial stress, likely promoting MAOM with more microbially processed signatures. NanoSIMS analyses revealed microscale organic matter patches sparsely covering clay-sized particles, indicating that SOC storage is decoupled from mineral surface area and highlighting the role of organic inputs and microbial activity in MAOM formation. Higher MAOM under MP not only increased SOC stocks but also enhanced cation exchange capacity, demonstrating that targeted pasture management can exceed native SOC stocks while improving nutrient retention.

草地管理是提高热带草原土壤有机碳（SOC）储量的关键，但SOC恢复通常被认为仅仅是土地利用变化后历史损失的补充。目前尚不清楚管理的feralsols是否能够超过原生植被（NV）的SOC储量，以及驱动这种收益的机制是什么。本研究对比了无管理退化草场（DP）和施肥管理草场（MP） 24年后土壤有机碳库、化学组成和养分保持能力。结果表明，土壤有机碳储量主要由矿物相关有机质（MAOM）库介导。与NV相比，DP土壤的MAOM储量减少（119比92 Mg C ha - 1），而MP土壤的MAOM储量为148 Mg C ha - 1。在DP中，土壤酸度、低养分有效性和较差的饲料投入诱导了微生物胁迫（如磷脂脂肪酸谱所示），可能限制了MAOM的形成，并产生富含较少羰基碳水化合物的MAOM。相比之下，MP的石灰化和施肥缓解了Ferralsol的低pH和养分缺乏，提高了牧草产量，减少了微生物胁迫，可能促进了具有更多微生物处理特征的MAOM。NanoSIMS分析显示，微尺度的有机质斑块稀疏地覆盖在粘土大小的颗粒上，表明有机碳储量与矿物表面积分离，并突出了有机输入和微生物活动在MAOM形成中的作用。高MAOM不仅增加了土壤有机碳储量，还增强了阳离子交换能力，表明有针对性的牧场管理可以在提高土壤有机碳储量的同时提高养分保有量。

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引用次数: 0

Response of element cycling and budgets to nutrient additions in a tropical montane forest of Ecuador 厄瓜多尔热带山地森林元素循环和收支对养分添加的响应

IF 6.6 1区农林科学 Q1 SOIL SCIENCE

Geoderma

Pub Date : 2026-02-01 DOI: 10.1016/j.geoderma.2026.117698

Andre Velescu , Jürgen Homeier , Carlos Iván Espinosa , Wolfgang Wilcke

The tropical montane forests in southern Ecuador are subject to rising nitrogen (N), low phosphorus (P), and episodic calcium (Ca) deposition. To investigate the response of the vegetation, soil organic layer and mineral soil to 0.3 m depth to increased nutrient inputs, we initiated in 2008 an interdisciplinary Nutrient Manipulation Experiment (NUMEX) at 2000 m a.s.l. We have applied N as urea at 50 kg ha⁻¹ year⁻¹, P as NaH₂PO₄ at 10 kg ha⁻¹ year⁻¹, combined N and P at 50 + 10 kg ha⁻¹ year⁻¹, and Ca (as CaCl₂), at 10 kg ha⁻¹ year⁻¹. From 2008 to 2012, we set up annual budgets by calculating net fluxes of N, P, Ca and Na for the canopy, the organic layer and the mineral soil and determined δ¹⁵N values in the foliage of the four most abundant tree species, litterfall and organic layer. The addition of P and N + P increased P leaching from the canopy, suggesting a reduced retention of deposited P by canopy organisms. All added nutrients were largely retained in the soil organic layer and tightly cycled between the organic layer and the vegetation via litterfall and throughfall. The small leaching losses of N, P, Ca and Na from the organic layer were retained in the upper mineral soil. The retention of the added nutrients in the ecosystem indicated a strong nutrient demand. Nevertheless, the ¹⁵N enrichment in the organic layer was an early indicator of beginning N losses from the ecosystem by leaching and volatilization, which could not yet be detected by our flux-based budgeting approach.

厄瓜多尔南部的热带山地森林受到氮(N)上升、磷(P)低和偶发性钙（Ca）沉积的影响。为了研究0.3 m以下植被、土壤有机层和矿质土对增加养分投入的响应，我们于2008年启动了一项2000 m a.s.l的跨学科养分调控实验（NUMEX）。我们在50 kg ha−1年−1施用N作为尿素，在10 kg ha−1年−1施用P作为NaH2PO4，在50 + 10 kg ha−1年−1施用N和P，在10 kg ha−1年−1施用Ca（作为CaCl2）。2008 - 2012年，通过计算林冠层、有机层和矿质土N、P、Ca、Na的净通量，建立了林冠层、有机层和矿质土的年度收支，并测定了4种最丰富树种、凋落物和有机层的叶片δ15N值。P和N + P的添加增加了冠层的磷淋溶，表明冠层生物对沉积磷的保留减少。所有添加的养分大部分保留在土壤有机层中，并通过凋落物和穿透物在有机层和植被之间紧密循环。有机层中N、P、Ca和Na的少量淋失被保留在上层矿质土中。添加的营养物质在生态系统中的保留表明了强烈的营养需求。然而，有机层中的15N富集是生态系统通过淋滤和挥发开始的N损失的早期指标，这还不能通过基于通量的预算方法检测到。

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引用次数: 0

Phosphorus dynamics in acidic and neutral fen soils − does vivianite limit phosphorus release? 酸性和中性沼泽土壤中磷的动态变化——橄榄石是否限制了磷的释放？

IF 6.6 1区农林科学 Q1 SOIL SCIENCE

Geoderma

Pub Date : 2026-02-01 DOI: 10.1016/j.geoderma.2026.117685

Adrian F. Florea , Dominik H. Zak , Rasmus Jes Petersen , Carolin L. Dreher , Andreas Kappler , Hans Christian B. Hansen

Drainage and cultivation of organic lowland peat soils have profoundly altered their hydrological and biogeochemical functions, increasing greenhouse gas emissions and phosphorus (P) mobilization due to enhanced mineralization. Rewetting is increasingly promoted to mitigate these impacts. However, intensive agricultural use has led to P accumulation, primarily bound to Fe(III)(oxyhydr)oxide minerals, raising the risk of P release under anoxic conditions and challenging the restoration of these systems as nutrient sinks. Predicting P release remains difficult due to complex interactions, including P re-sorption to metal oxides with remaining P binding places and precipitation as Fe(II) or Ca phosphates such as vivianite and hydroxyapatite.

This study investigates Fe(III)(oxyhydr)oxide reduction extent and associated P mobilization in two contrasting Danish lowland peatlands over 24 months: the acidic Vejrumbro and neutral-alkaline Løvenborg. Oxalate-extractable Fe, Al, and P (Fe_ox, Al_ox, P_ox) differed substantially between sites. Løvenborg exhibited higher Fe_ox (198–241 mmol kg⁻¹) and Al_ox (41–49 mmol kg⁻¹) than Vejrumbro (Fe_ox: 27–122 mmol kg⁻¹; Al_ox: 4.5–40 mmol kg⁻¹), resulting in greater P sorption capacity (PSC: 239–287 vs. 44–155 mmol kg⁻¹). The degree of P saturation (DPS) remained low at both sites (<10%).

Under winter or wet field conditions, Fe(III)(oxyhydr)oxide reduction extent reached up to 100%, indicating complete dissolution of the Fe_ox pool. Despite extensive reduction, soluble P (P_Sol) remained low in Løvenborg (≤0.3 mg L⁻¹), whereas Vejrumbro exhibited high P_Sol concentrations (up to 4.7 mg L⁻¹). Powder X-ray diffraction and Mössbauer spectroscopy confirmed vivianite formation in Løvenborg, demonstrating P immobilization via precipitation. Moreover, in Løvenborg, the saturation index calculated using the geochemical model Minteq showed values between 2.5 and 4.2 with respect to vivianite supersaturation, while for Ca-P precipitates such as hydroxyapatite, Løvenborg soils show near equilibrium (0.09) to slight undersaturation (−1.8). In contrast, P retention in Vejrumbro was mainly through adsorption onto residual Fe and Al oxide minerals.

These results indicate that P release risk models must go beyond re-adsorption, and include precipitation pathways, which depend on metal-oxide content, cation availability (e.g., Ca²⁺, Fe²⁺), pH, alkalinity, and the extent of Fe(III) reduction. Incorporating key geochemical indicators—such as pH, sorption capacity, calcium content, Fe(III) reduction extent, and alkalinity may lead to better classification of peat soils and guide rewetting strategies safeguarding minimal P release.

有机低地泥炭土的排水和耕作深刻地改变了其水文和生物地球化学功能，增加了温室气体排放和磷(P)的动员。为了减轻这些影响，越来越多的人提倡重新润湿。然而，集约化农业利用导致了磷的积累，主要与Fe(III)（氧合）氧化物矿物结合，增加了缺氧条件下磷释放的风险，并挑战了这些系统作为养分汇的恢复。由于复杂的相互作用，预测磷的释放仍然很困难，包括磷再吸附到金属氧化物上，剩余的P结合位置和沉淀为铁（II）或钙磷酸盐，如橄榄石和羟基磷灰石。本研究调查了丹麦两个不同的低地泥炭地（酸性的Vejrumbro和中性碱性的Løvenborg）在24个月内的铁（III）（氧）氧化物还原程度和相关的磷动员。草酸盐可提取的Fe， Al和P （Feox, Alox, Pox）在不同位点之间差异很大。与Vejrumbro （Feox: 27-122 mmol kg - 1; Alox: 4.5-40 mmol kg - 1）相比，Løvenborg表现出更高的Feox （199 - 241 mmol kg - 1）和Alox (41-49 mmol kg - 1)，从而产生更大的P吸附能力（PSC: 239-287 vs. 44-155 mmol kg - 1）。两个地点的磷饱和度（DPS）都很低（10%）。在冬季或湿田条件下，Feox池的Fe(III)（氧）氧化物还原程度高达100%，表明Feox池完全溶解。尽管大量减少，但Løvenborg的可溶性磷（PSol）仍然很低（≤0.3 mg L−1），而Vejrumbro的PSol浓度很高（高达4.7 mg L−1）。粉末x射线衍射和Mössbauer光谱证实在Løvenborg形成了vivianite，证明P通过沉淀固定。此外，利用地球化学模型Minteq计算的Løvenborg土壤的钙磷沉淀饱和度指数在2.5 ~ 4.2之间，而对于羟基磷灰石等钙磷沉淀，Løvenborg土壤表现为接近平衡（0.09）至轻度欠饱和（- 1.8）。而在Vejrumbro中，P的滞留主要是通过吸附在残余的Fe和Al氧化物矿物上。这些结果表明，P释放风险模型必须超越再吸附，并包括沉淀途径，这取决于金属氧化物含量、阳离子有效性（如Ca2+、Fe2+）、pH、碱度和Fe（III）还原程度。结合关键的地球化学指标，如pH、吸附能力、钙含量、铁（III）还原程度和碱度，可以更好地分类泥炭土，并指导保证最小磷释放的再湿策略。

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引用次数: 0

A calibration-free approach for measuring soil thermal properties and bulk density using the thermo-TDR technique 一种使用热- tdr技术测量土壤热特性和体积密度的免校准方法

IF 6.6 1区农林科学 Q1 SOIL SCIENCE

Geoderma

Pub Date : 2026-01-16 DOI: 10.1016/j.geoderma.2026.117679

Wei Peng , Meng Zhang , Yili Lu , Zhengchao Tian , Yajing Wang , Tusheng Ren

Traditional heat-pulse methods for determining soil thermal properties require frequent probe spacing calibrations due to their susceptibility to geometric errors in heat capacity (C) estimation. Here we present a novel calibration-free thermo-TDR technique as a methodological innovation that concurrently measures soil bulk density (ρ_b), thermal conductivity (λ), and C by integrating heat-pulse theory with soil constitutive relationships within a unified inversion framework. The procedure: (i) directly calculates λ from heat-pulse signals using physical probe spacing without calibration; (ii) predicts ρ_b via a λ-ρ_b model that is parameterized with soil texture and TDR-derived water content (θ_TDR); and (iii) estimates C from ρ_b and θ_TDR using the de Vries (1963) model. This approach eliminates the need for probe spacing calibration, which is a key limitation of traditional methods. Laboratory validation with packed soils yielded high accuracy (RMSE: ≤0.08 Mg m⁻³ for ρ_b; ≤0.11 MJ m⁻³ K⁻¹ for C). Field deployments tracked dynamic ρ_b and C during natural drying events (mean RMSE: 0.09 Mg m⁻³ for ρ_b, 0.13 MJ m⁻³ K⁻¹ for C), outperforming traditional spaced probe methods that were sensitive to sensor misalignment. Eliminating probe spacing calibration makes this approach ideal for long-term monitoring and integration with automated field sensor networks, advancing studies of soil–water-energy dynamics in agronomic and vadose zone hydrology.

传统的热脉冲法用于测定土壤热性质，由于其在热容(C)估计中容易产生几何误差，需要频繁地校准探针间距。在这里，我们提出了一种新的无需校准的热- tdr技术，作为一种方法创新，通过在统一的反演框架内将热脉冲理论与土壤本构关系结合起来，同时测量土壤容重（ρb），导热系数（λ）和C。程序：(i)利用物理探针间距直接从热脉冲信号计算λ，无需校准；（ii）通过以土壤质地和tdr衍生的含水量（θTDR）为参数化的λ-ρb模型预测ρb；（iii）使用de Vries（1963）模型从ρb和θTDR中估计C。这种方法消除了对探针间距校准的需要，这是传统方法的一个关键限制。实验室验证的填充土壤具有很高的准确性（ρb的RMSE≤0.08 Mg m−3；C的RMSE≤0.11 MJ m−3 K−1）。现场部署跟踪自然干燥事件期间的动态ρb和C (ρb的平均RMSE: 0.09 Mg m−3，C的平均RMSE: 0.13 MJ m−3 K−1)，优于传统的间隔探针方法，该方法对传感器偏差敏感。消除探针间距校准使这种方法非常适合长期监测和集成自动化现场传感器网络，推进农学和渗透带水文学中土壤-水-能量动力学的研究。

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引用次数: 0

Temporal and Vertical Variability of Post-Tillage Topsoil Hydraulic Properties at a Local Scale 局部尺度耕作后表土水力特性的时间和垂直变化

IF 6.6 1区农林科学 Q1 SOIL SCIENCE

Geoderma

Pub Date : 2026-01-16 DOI: 10.1016/j.geoderma.2026.117683

Jan-František Kubát, Michal Vrána, Adam Babuljak, David Zumr

Soils exhibit considerable variability in their physical and hydraulic properties, which can change both spatially and temporally. However, studies capturing short-term temporal and internal vertical variability within tilled topsoil remain limited. In this one-year study (May 2023–2024), we investigated seasonal changes in the physical and hydraulic properties of the bare topsoil after tillage in a humid continental climate in Czechia. Monthly sampling was conducted on a 16 m² plot, targeting the upper 12 cm of soil, divided into 0 to 5 cm and 7 to 12 cm layers. A total of 28 disturbed and 107 undisturbed samples were collected, and 40 soil water retention curves (SWRCs) were measured and fitted with the van Genuchten–Mualem model to derive hydraulic parameters (α, n, θ_r, θ_s, K_s). Robust statistical analyses (permutation tests, Kruskal–Wallis, Dunn’s test, LOWESS, and MANOVA) were used to evaluate vertical and temporal variability. The results revealed significant changes in the hydraulic properties of the fitted devices. The depth explained approximately half of the total multivariate variance (η² ≈ 0.5), while time accounted for roughly one-third (η² ≈ 0.3–0.4). The upper layer exhibited greater heterogeneity in the n parameter (1.404 ± 0.126) compared to the deeper layer (1.254 ± 0.103), while α showed comparable variability (0.060 ± 0.019 vs. 0.075 ± 0.024). These moderate-to-large effect sizes indicate that, even within the first 12 cm, hydraulic behavior is neither uniform nor static. The contrasting patterns between the fitted full SWRCs and their derived parameters highlight the importance of evaluating both datasets jointly. Relying solely on parameter statistics or individual retention curve risks overlooking meaningful temporal and vertical dynamics. Our findings demonstrate that post-tillage topsoil evolves structurally and hydraulically even in the absence of vegetation or management, emphasizing the need for depth- and time-resolved parameterization in hydrological and soil-process modeling.

土壤的物理和水力特性表现出相当大的变异性，可以在空间和时间上发生变化。然而，在耕作表土中捕捉短期时间和内部垂直变化的研究仍然有限。在这项为期一年（2023-2024年5月）的研究中，我们研究了捷克湿润大陆性气候下裸露表土耕作后物理和水力特性的季节变化。每月取样面积为16 m2，取样范围为土壤上部12 cm，分为0 ~ 5 cm层和7 ~ 12 cm层。共采集28个扰动样和107个未扰动样，测量40条土壤保水曲线（SWRCs），采用van Genuchten-Mualem模型拟合得到水力参数（α, n, θr, θs, Ks）。采用稳健的统计分析（排列检验、Kruskal-Wallis检验、Dunn检验、LOWESS和方差分析）来评估垂直和时间变异。结果显示，安装装置的水力性能发生了显著变化。深度解释了大约一半的多变量方差（η2≈0.5），而时间解释了大约三分之一（η2≈0.3-0.4）。上层n参数的异质性（1.404±0.126）大于下层（1.254±0.103），而α参数的异质性（0.060±0.019 vs. 0.075±0.024）具有可比性。这些中等到较大的效应表明，即使在最初的12厘米内，水力行为既不是均匀的，也不是静态的。拟合的完整swrc及其衍生参数之间的对比模式突出了联合评估两个数据集的重要性。仅仅依赖于参数统计数据或个人留存曲线可能会忽视有意义的时间和垂直动态。我们的研究结果表明，即使在没有植被或管理的情况下，耕作后的表土在结构和水力上也会发生变化，这强调了在水文和土壤过程建模中需要深度和时间分辨参数化。

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引用次数: 0

Stoichiometry of peatlands and plants: Mutual interactions in biogeochemical cycles 泥炭地和植物的化学计量学：生物地球化学循环中的相互作用

IF 6.6 1区农林科学 Q1 SOIL SCIENCE

Geoderma

Pub Date : 2026-01-16 DOI: 10.1016/j.geoderma.2026.117687

Wojciech Piaszczyk , Andrzej Szlachta , Stanisław Łyszczarz , Norbert Szymański , Michał Jasik , Mirosław Żelazny , Stanisław Małek , Jarosław Lasota , Ewa Błońska

Although peatlands cover only a small fraction of the Earth’s surface, they store large amounts of carbon and play a key role in global biogeochemical cycles. A joint assessment of the stoichiometry of biogenic elements (C, N and P) and nutrients ratios may improve our understanding of soil–plant interactions across different types of Histosol. The aim of this study was to analyse the stoichiometry of C:N:P and nutrients ratios in peat soils and conifer needles (Picea abies and Pinus sylvestris) across three different histosol types: fibric, hemic and sapric. Particular emphasis was placed on soil–plant relationships and evaluating the potential of stoichiometric indicators to diagnose peatland condition. Samples were collected from 255 sites across Poland. Composite soil samples (0–15 cm depth) and conifer needles were analysed for C and N using an elemental analyser, and for Ca, Mg, K, Al and P using ICP-OES. Ratios (C/N, C/P, N/P, Ca/Mg, Ca/Al and Ca·K·Mg/Al) were then calculated. Statistical procedures included descriptive statistics (median and quartile deviation), a Kruskal–Wallis test (p < 0.05), a principal component analysis (PCA), generalised linear models (GLM), Spearman’s rank correlations and simple linear regressions. Soil carbon content, as well as the C/N, C/P and N/P ratios, decreased systematically from fibric to sapric histosols. Meanwhile, the contents of Ca, Mg, K and Al were significantly higher in sapric soils. In plants, the contents of C, N and P, as well as the C/N, C/P and N/P ratios, did not differ between histosol types. However, the ratios (particularly Ca/Al and Ca·K·Mg/Al) were highest in sapric histosols. Soil–plant correlations were weak for C/N, C/P, and N/P, but slightly stronger for Ca/Al and Ca·K·Mg/Al. PCA (PC1 = 35.52 %; PC2 = 19.41 %) revealed a clear separation, with plants associated with phosphorus and nutrients ratios and soils grouped with C/N and C/P. GLM confirmed the significant effects of both sample and histosol types, with an interaction observed for most indices (except Ca/Mg). Both classical ratios (C/N, C/P and N/P) and ratios (Ca/Al, Ca/Mg and Ca·K·Mg/Al) provide complementary insights into peatland functioning. The decline of C/N and C/P ratios with increasing humification, combined with higher nutrient ratios, indicates their potential for diagnosing peatland degradation and monitoring nutrient cycling dynamics.

尽管泥炭地只覆盖了地球表面的一小部分，但它们储存了大量的碳，在全球生物地球化学循环中发挥着关键作用。对生物源元素（C、N和P）的化学计量学和养分比例的联合评估可能会提高我们对不同类型组织土壤中土壤-植物相互作用的理解。本研究的目的是分析泥炭土和针叶松（Picea abies和Pinus sylvestris）在三种不同组织类型（纤维、化学和辛辣）中的C:N:P和养分比的化学计量学。特别强调土壤-植物关系和评价化学计量指标诊断泥炭地状况的潜力。样本是从波兰255个地点收集的。使用元素分析仪分析复合土壤样品（0-15 cm深度）和针叶针叶的C和N，使用ICP-OES分析Ca、Mg、K、Al和P。计算C/N、C/P、N/P、Ca/Mg、Ca·K·Mg/Al比值。统计程序包括描述性统计（中位数和四分位数偏差）、Kruskal-Wallis检验（p < 0.05）、主成分分析（PCA）、广义线性模型（GLM）、Spearman秩相关和简单线性回归。土壤碳含量、碳氮比、碳磷比和氮磷比从纤维到树胶呈系统下降趋势。同时，含盐土壤中Ca、Mg、K、Al的含量显著高于含盐土壤。在植物中，C、N、P含量以及C/N、C/P和N/P比值在不同类型的组织溶胶中没有差异。其中，以Ca/Al和Ca·K·Mg/Al比值最高。C/N、C/P和N/P的土壤-植物相关性较弱，而Ca/Al和Ca·K·Mg/Al的土壤-植物相关性略强。PCA （PC1 = 35.52%; PC2 = 19.41%）显示出明显的分离，植物与磷和养分比例相关，土壤与C/N和C/P分组。GLM证实了样品和组织溶胶类型的显著影响，在大多数指数中观察到相互作用（Ca/Mg除外）。经典比率（C/N、C/P和N/P）和比率（Ca/Al、Ca/Mg和Ca·K·Mg/Al）都为泥炭地功能提供了补充见解。C/N和C/P比值随腐殖化程度的增加而下降，并结合更高的养分比率，表明它们在诊断泥炭地退化和监测养分循环动态方面具有潜力。

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引用次数: 0

Isotopy, micromorphology and composition of pedogenic gypsum in loess-palaeosol sequences in the Ebro Valley as a combined paleoenvironmental proxy 埃布罗河谷黄土-古土壤层序中成土石膏的同位素、微形态和组成及其复合古环境指标

IF 6.6 1区农林科学 Q1 SOIL SCIENCE

Geoderma

Pub Date : 2026-01-15 DOI: 10.1016/j.geoderma.2025.117667

D. Álvarez , E. Playà , O. Artieda , R. Rodríguez-Ochoa , J.R. Olarieta , R.M. Poch

The loess palaeosol sequences in the Ebro valley are associated with arid and semi-arid climates in the past, where the main pedogenic process is the mobilisation of carbonate and gypsum through the soil, resulting in secondary accumulations. Due to the fact that, in this context, the conservation of palaeoenvironmental indicators is very limited, the objective of this research is to explore the potential of pedogenic gypsum to provide with information about the palaeoenvironmental conditions affecting its development and preservation.

This study has consisted in the sampling and analysis of pedogenic gypsum accumulations from five Loess-Palaeosol Sequences (LPS) applying several approaches and analytical techniques. Traditional methods based on the morphological study of gypsum and supported by micromorphological research have been applied, allowing us the observation of crystalline shapes, pedofeatures and mineral arrangements. We also performed isotopic analyses of pedogenic gypsum, including the isotopic signature of the stable sulphate (δ³⁴S, δ¹⁸O) and gypsum hydration water (δ²H, δ¹⁸O). Besides, the minor and trace elements composition (Ba, Sr, Na, K, and Mg) was also analysed.

Despite the difficulties when analysing pedogenic gypsum, due in part to its high solubility, our results show that the intensity of the dissolution/reprecipitation processes combined with the loess sedimentation rates determine gypsum characteristics and distribution in the studied loess profiles. Besides helping to determine the gypsum primary source areas, isotopic and micromorphological analyses suggest possible regional and temporal paleoclimatic differences (more/less arid) from the close or more open systems of gypsum in relation to meteoric water.

In addition, the minor and trace elements composition suggests the presence of fluid and solid inclusions in the gypsum crystals of some horizons. This corresponds to gypsum formation in a medium with water rich in sulphates and other salts, and an increased proportion of primary gypsum in the sediment, in contrast to the precipitation of gypsum in unsaturated water.

The combination of different methods has confirmed that pedogenic gypsum is a potential tool for improving palaeoenvironmental knowledge in arid and semi-arid regions. However, due to its limitations, it is recommended to combine additional techniques and indicators to use pedogenic gypsum as an effective palaeoenvironmental proxy.

埃布罗河谷的黄土古土壤序列与过去的干旱和半干旱气候有关，其主要的成土过程是碳酸盐和石膏通过土壤的动员，导致次生堆积。由于在此背景下，古环境指标的保存非常有限，本研究的目的是探索成土石膏的潜力，为影响成土石膏发育和保存的古环境条件提供信息。本研究采用多种方法和分析技术，对5个黄土-古土壤层序（LPS）的成土石膏堆积进行了采样和分析。基于石膏形态学研究和微形态学研究的传统方法已经得到应用，使我们能够观察到晶体形状、土壤特征和矿物排列。对成土石膏进行了同位素分析，包括稳定硫酸盐（δ34S, δ18O）和石膏水化水（δ2H, δ18O）的同位素特征。此外，还分析了微量元素（Ba、Sr、Na、K、Mg）的组成。尽管在分析成土石膏时存在困难，部分原因是其溶解度高，但我们的研究结果表明，溶解/再沉淀过程的强度与黄土沉积速率相结合，决定了所研究的黄土剖面中石膏的特征和分布。同位素和微形态分析除了有助于确定石膏的主要来源地区外，还从石膏的封闭或开放系统与大气水的关系中揭示了可能的区域和时间古气候差异（多或少干旱）。此外，微量元素和微量元素的组成表明，在某些层位的石膏晶体中存在流体和固体包裹体。这与石膏在富含硫酸盐和其他盐的水的介质中形成相对应，并且与石膏在不饱和水中的沉淀相比，沉积物中初级石膏的比例增加。不同方法的结合证实了成土石膏是改善干旱和半干旱地区古环境知识的潜在工具。然而，由于其局限性，建议结合其他技术和指标，将成土石膏作为有效的古环境指标。

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引用次数: 0

Microbial and plant-derived carbon contributions to particulate and mineral-associated organic carbon in perennial and annual cropping systems 多年生和一年生作物系统中微生物和植物源碳对颗粒和矿物相关有机碳的贡献

IF 6.6 1区农林科学 Q1 SOIL SCIENCE

Geoderma

Pub Date : 2026-01-15 DOI: 10.1016/j.geoderma.2026.117688

Yiwei Shang , Zhi Liang , Imran Ahammad Siddique , Michaela Dippold , Diego Abalos , Jørgen Eivind Olesen

Perennial cropping systems hold great potential to enhance soil organic carbon (SOC) stocks and contribute to climate change mitigation. However, the effects of perennial crops on SOC fractions with different stabilities remain poorly understood. Particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) are considered to have different formation mechanisms and different stabilities. Plant- and microbial-derived carbon (C) are the main origins of SOC, yet their relative contributions to POC and MAOC remain unclear. Here, based on an 11-year experiment, we compared two perennial cropping systems (festulolium and grass-clover) with an annual cropping system (maize), to investigate their effects on soil POC and MAOC, and quantify the contribution of plant- and microbial-derived C to these two soil C fractions using lignin phenols and amino sugars as biomarkers.

The soil of the two perennials had higher POC and MAOC than maize at 0–20 cm soil depth, with higher proportions of POC in SOC. The higher POC of the two perennials was linked to their significantly higher fungal and bacterial necromass C in POC. Total microbial necromass C accounted for only 29% of POC and 36% of MAOC at 0–20 cm across all systems, suggesting that plant-derived C dominates these two C pools. However, no significant differences were detected in the lignin phenols content in POC and MAOC at 0–20 cm. Our results challenge the conventional assumption that microbial necromass C dominates MAOC, highlighting the role of plant-derived C in POC and MAOC, which could have a greater influence on soil C sequestration in climates with low mean annual temperature than previously assumed. Given that only two biomarkers were used, interpretations should not be extrapolated beyond their analytical scope.

多年生种植系统在增加土壤有机碳储量和促进减缓气候变化方面具有巨大潜力。然而，多年生作物对不同稳定性有机碳组分的影响尚不清楚。颗粒有机碳（POC）和矿物伴生有机碳（MAOC）被认为具有不同的形成机制和不同的稳定性。植物碳和微生物碳(C)是有机碳的主要来源，但它们对POC和MAOC的相对贡献尚不清楚。在此，基于一项为期11年的实验，我们比较了两种多年生种植制度（黄草叶和草三叶草）与一年生种植制度（玉米），研究了它们对土壤POC和MAOC的影响，并以木质素酚类和氨基糖作为生物标志物，量化了植物和微生物来源的C对这两种土壤C组分的贡献。在0 ~ 20 cm土壤深度，两种多年生植物土壤POC和MAOC均高于玉米，且POC在有机碳中所占比例较高。两种多年生植物较高的POC与POC中较高的真菌和细菌坏死团C有关。在所有系统中，0-20 cm处微生物坏死团C仅占POC的29%和MAOC的36%，表明植物来源的C在这两个C库中占主导地位。而在0 ~ 20 cm， POC和MAOC的木质素酚含量无显著差异。我们的研究结果挑战了微生物坏死体C主导MAOC的传统假设，强调了植物来源的C在POC和MAOC中的作用，这可能对年平均气温较低的气候条件下的土壤碳封存产生更大的影响。鉴于只使用了两种生物标志物，解释不应超出其分析范围。

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引用次数: 0