Soil & Tillage Research最新文献_第10页

Effects of long-term fertiliser application on cropland soil carbon dynamics mediated by potential shifts in microbial carbon use efficiency 长期施肥对微生物碳利用效率潜在变化介导的农田土壤碳动态的影响

IF 6.1 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2024-12-12 DOI: 10.1016/j.still.2024.106418

Di He , Guihua Li , Zhongkui Luo , Enli Wang

Fertiliser application in agricultural ecosystems affects not only the potential carbon input (via crop biomass and/or manure) into the soil, but also a series of soil processes regulating soil organic carbon (SOC) decomposition. A detailed mechanistic understanding of how fertiliser regimes affect SOC dynamics is still needed. Here we constrained the Agricultural Production Systems sIMulator (APSIM model) to long-term (> 20 years) crop and SOC measurement data collected from four trials under contrasting climatic and edaphic conditions in China. By optimizing the three most influential model parameters for SOC dynamics, i.e., the decomposition rate constant of the slow humic pool (rd_hum), the fraction of stable (non-decomposable) pool (Finert), and microbial carbon use efficiency (CUE), we analysed their responses to fertiliser application regimes to infer potential mechanisms underpinning SOC changes. Our results revealed strong effects of fertiliser regimes and sites on CUE. Sites, fertiliser regimes and their interactions explained 67 % and 1.4 % of the variation in the derived CUE and rd_hum values, respectively. Linear mixed-effects modelling showed that soil C:N ratio together with carbon input amount as a random effect explained 90 % of the variation in optimised CUE values across sites and treatments. Such impact on CUE could partly explain the impact of fertiliser and carbon input on the priming effect. Fertilisers with more carbon input (i.e., straw or manure) increased CUE by 27 % - 57 % compared with chemical fertilisers in three of four sites. However, their impacts on rd_hum was divergent when decomposition of carbon pools was simulated with first-order processes. Our results demonstrate the significant effects of fertiliser regimes on CUE and thus SOC dynamics, highlighting the importance of site-specific calibration of the current SOC models and the need to quantify uncertainty bounds of any model simulated further SOC sequestration. This study also calls for developing a clear understanding to quantify the relationship between carbon input and CUE under different environment.

在农业生态系统中施肥不仅会影响（通过作物生物量和/或粪肥）向土壤中的潜在碳输入，还会影响一系列调节土壤有机碳（SOC）分解的土壤过程。我们仍然需要从机理上详细了解肥料制度是如何影响 SOC 动态的。在此，我们将农业生产系统模拟器（APSIM）模型与中国四个气候和土壤条件截然不同的试验中收集的长期（20 年）作物和 SOC 测量数据相结合。通过优化对 SOC 动态影响最大的三个模型参数，即缓慢腐殖质池的分解速率常数（rd_hum）、稳定（不可分解）池的比例（Finert）和微生物碳利用效率（CUE），我们分析了它们对化肥施用制度的响应，以推断 SOC 变化的潜在机制。我们的研究结果表明，施肥制度和施肥地点对碳利用效率有很大影响。在得出的 CUE 和 rd_hum 值的变化中，地点、施肥制度及其交互作用分别解释了 67% 和 1.4%。线性混合效应模型显示，土壤碳氮比和作为随机效应的碳输入量可解释不同地点和处理的优化 CUE 值之间 90% 的差异。这种对 CUE 的影响可以部分解释肥料和碳投入对引诱效应的影响。与化肥相比，在四个地点中的三个地点，碳投入较多的肥料（即秸秆或粪肥）可将 CUE 提高 27% - 57%。然而，在用一阶过程模拟碳库分解时，它们对 rd_hum 的影响是不同的。我们的研究结果表明，化肥制度对 CUE 以及 SOC 动态有重大影响，这突出表明了针对具体地点校准当前 SOC 模型的重要性，以及量化任何模拟进一步 SOC 固碳的模型的不确定性边界的必要性。这项研究还要求对不同环境下的碳输入与 CUE 之间的关系有一个清晰的量化认识。

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引用次数: 0

Nature-based accumulation of organic carbon and nitrogen in citrus orchard soil with grass coverage 草地覆盖下柑橘园土壤有机碳氮的自然积累

IF 6.1 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2024-12-12 DOI: 10.1016/j.still.2024.106419

Ludan Chen , Yuhai Bao , Xiubin He , Jie Yang , Qiao Wu , Jiaorong Lv

Grass coverage in orchards has increasingly become a sustainable practice to improve soil quality, reduce soil erosion, increase water infiltration, and enhance biodiversity and ecosystem services. It is likely to gain further adoption as a promising nature-based measure to increase organic carbon and nitrogen storage in soil. However, there is still a lack of comprehensive global quantification regarding the accumulation and availability of soil organic carbon (SOC) and total nitrogen (STN) after grass coverage in citrus orchards. A global meta-analysis was conducted to comprehensively evaluate the effects of grass coverage on SOC and STN dynamics in citrus orchards, as well as the patterns influenced by various factors. Compared to clean tillage, the accumulation rates of SOC and STN were significantly enhanced with grass coverage, with an increase of 19.98 Mg ha⁻¹ yr⁻¹ and 2.27 Mg ha⁻¹ yr⁻¹ , respectively. The microbial biomass carbon (MBC), dissolved organic carbon (DOC) and available nitrogen (AN) exhibited significantly increases following grass coverage, with average enhancements of 13.90 %, 17.94 %, and 18.04 %, respectively. The primary factors influencing the variation in SOC and STN were identified as grass age and growth modes. When grass coverage reached or exceeded 10 years and was applied uniformly across the entire orchard (full coverage), there was a more pronounced increase in SOC and STN levels. The present study provides policymakers and orchard managers with science-based evidence to guide adaptive management practices that enhance SOC and STN stocks, improve soil conditions, and increase orchard resilience to climate change.

果园植草已逐渐成为一种可持续的做法，可改善土壤质量、减少水土流失、增加水分渗透以及提高生物多样性和生态系统服务。作为增加土壤有机碳和氮储存的一种有前途的自然措施，它很可能会被进一步采用。然而，关于柑橘园植草后土壤有机碳（SOC）和全氮（STN）的积累和可用性，目前仍缺乏全面的全球量化研究。为了全面评估覆草对柑橘园土壤有机碳（SOC）和全氮（STN）动态的影响，以及受各种因素影响的模式，我们进行了一项全球荟萃分析。与清洁耕作相比，草覆盖显著提高了 SOC 和 STN 的积累率，分别增加了 19.98 兆克/公顷-¹年-¹和 2.27 兆克/公顷-¹年-¹。草地覆盖后，微生物生物量碳（MBC）、溶解有机碳（DOC）和可利用氮（AN）明显增加，平均增幅分别为 13.90 %、17.94 % 和 18.04 %。影响 SOC 和 STN 变化的主要因素是草龄和生长模式。当草的覆盖年限达到或超过 10 年，并在整个果园均匀施用（全覆盖）时，SOC 和 STN 水平会有更明显的提高。本研究为政策制定者和果园管理者提供了科学依据，以指导适应性管理实践，从而提高 SOC 和 STN 储量、改善土壤条件并增强果园对气候变化的适应能力。

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引用次数: 0

High soil bacterial diversity increases the stability of the community under grazing and nitrogen 高的土壤细菌多样性增加了放牧和施氮条件下群落的稳定性

IF 6.1 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2024-12-10 DOI: 10.1016/j.still.2024.106414

Muhammad Usman , Mengyuan Wang , Yang Liu , Lan Li , Xiumin Zhang , Tianhao Xiao , Fujiang Hou

Grasslands are one of the major terrestrial ecosystems facing severe degradation due to climatic changes and anthropogenic activities. In northwest China, the Typical steppe and alpine meadows are the major grasslands with diverse ecosystems. These grasslands are facing degradation due to excessive livestock grazing and nitrogen (N) deposition that can alter the overall grassland ecosystem, along with the soil bacterial communities and their role in the ecosystem. The bacterial community is vital for the sustainability of grassland ecosystems as it plays a crucial role in decomposing the dead organic matter and nutrient cycling. This study conducted a grazing and N addition experiment in alpine meadows and typical steppe. The impact of short-term N application and grazing on both grasslands' soil, plant, and bacterial communities was explored. Alpine meadows had higher bacterial richness (OTUs>2000) and diversity (Shannon index>6) than the typical steppe (OTUs<900; Shannon index<5.5) due to changes in climate and ecosystem. The alpha diversity (Shannon index) of the bacterial community was observed to increase under low grazing without N addition while adding medium N (100 kg/ha) without grazing increased the diversity. The combination of medium N (100 kg/ha) addition and low grazing resulted in the highest bacterial diversity in both grasslands. In contrast, the combination of N and high grazing decreased bacterial richness and diversity. The N addition and grazing affected the bacterial community composition in the typical steppe. The co-occurrence networks revealed that the network complexity in bacterial communities of alpine meadows was higher than that of typical steppe. The rich bacterial community and high soil nutrients in alpine meadows might have led to diverse microbial functionality, which provided stability to the bacterial network. The low nutrients and water availability in typical steppe lead to a lower bacterial richness, making the bacterial community vulnerable to the changes due to grazing and N. Climate is a significant factor in shaping the grassland ecosystem and its bacterial community. The changes in the grassland’s ecosystem due to high grazing and N deposition would highly affect the distressed microbial communities in arid and semiarid regions. Further, in-depth studies are required to understand the fate of these vulnerable grasslands and design management strategies for their protection.

草地是受气候变化和人类活动影响而面临严重退化的主要陆地生态系统之一。西北地区以典型草原和高寒草甸为主，生态系统多样。由于过度放牧牲畜和氮沉降，这些草地正面临退化，氮沉降会改变整个草地生态系统，以及土壤细菌群落及其在生态系统中的作用。细菌群落对草地生态系统的可持续性至关重要，因为它在分解死有机质和养分循环中起着至关重要的作用。本研究在高寒草甸和典型草原上进行了放牧加氮试验。探讨了短期施氮和放牧对草地土壤、植物和细菌群落的影响。高寒草甸细菌丰富度（OTUs>2000）和多样性（Shannon指数>；6）均高于典型草原(OTUs<900；由于气候和生态系统的变化，Shannon指数<；5.5)。低放牧不加氮条件下细菌群落的α多样性（Shannon指数）增加，不加氮条件下添加中氮（100 kg/ha）增加了细菌群落的多样性。中氮（100 kg/ha）加量和低放牧组合使两种草地的细菌多样性最高。氮与高放牧的组合降低了土壤细菌的丰富度和多样性。加氮和放牧对典型草原细菌群落组成有影响。共现网络表明，高寒草甸细菌群落的网络复杂性高于典型草原。高寒草甸丰富的细菌群落和丰富的土壤养分可能导致了微生物功能的多样化，从而为细菌网络提供了稳定性。典型草原的养分和水分利用率低，导致细菌丰富度较低，使细菌群落容易受到放牧和氮变化的影响。气候是影响草原生态系统及其细菌群落形成的重要因素。高放牧和氮沉降对干旱半干旱区草地生态系统的影响很大。进一步，需要深入研究这些脆弱草原的命运，并设计保护它们的管理策略。

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引用次数: 0

Rice straw management options impact soil phosphorus adsorption-desorption, kinetics and thermodynamics in rice-wheat system of north-western India 水稻秸秆管理方案对印度西北部水稻-小麦系统土壤磷吸附-解吸、动力学和热力学的影响

IF 6.1 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2024-12-09 DOI: 10.1016/j.still.2024.106403

Sandeep Sharma, Paawan Kaur

Fluctuations in soil management practices, temperature and moisture conditions can impact adsorption-desorption and bioavailability of phosphorus (P) in agricultural soils. Therefore, this study investigates P dynamics in straw-managed soils of Punjab collected from five treatments namely (1) conventional tillage (CT) after removal of rice straw (CT-R), (2) Treatment 1 plus biochar amendment at 2 Mg ha⁻¹ (CT+biochar), (3) zero tillage with straw retention as mulch (ZT+RM), (4) CT with straw incorporation (CT+RI) and (5) CT after rice residue burned (CT+RB) after three years from an ongoing experiment in rice-wheat cropping system. The adsorption-desorption of P followed pseudo second order kinetics (R²> 0.99) and Freundlich isotherm (R²> 0.95) for all the treatments and temperatures. Freundlich adsorption capacity (K_Fads) varied with the physico-chemical soil properties and ranged from 10.9 to 28.5, 14.3–32.2, 18.3–40.2, and 22.5–56.5 μg¹⁻ⁿg⁻¹mLⁿ at 15, 25, 35, and 45 ± 1°C, respectively. The sequential order of P adsorption was as follows: CT+ biochar > CT+RB > ZT+RM > CT+RI > CT-R, irrespective of temperature. Thermodynamic parameters revealed feasible, spontaneous and endothermic process indicative of physio-sorption via. hydrogen bonding as the dominant mechanism in in-situ straw managed soils. The Freundlich desorption coefficient (K_Fdes) ranged from 54.8 to 85.2, 39.9–60.8, 23.4–37.0, 29.6–45.7 and 19.4–36.7 μg¹⁻ⁿg⁻¹mLⁿ in CT+ biochar, CT+ RB, ZT+RM, CT+RI, CT-R, respectively at studied temperatures and was greater than adsorption in all treatments indicating hysteresis. The desorption sequence was observed as: CT-R > CT+RI > ZT+RM > CT+ RB> CT+ biochar. The greater adsorption and slower desorption of P under in-situ straw managed treatments (CT+biochar, CT+RB and ZT+RM) than CT-R and CT +RI, particularly CT+ biochar compared to CT-R will lead to more P retention in soil matrix thereby preventing eutrophication and deterioration of surface waters.

土壤管理方法、温度和湿度条件的波动会影响农业土壤中磷的吸附-解吸和生物利用度。因此，本研究调查了旁遮普省秸秆管理土壤中的磷动态，收集了五种处理，即：(1)秸秆去除后的常规耕作（CT）（CT- r），(2)处理1加2 Mg ha - 1的生物炭改良（CT+生物炭），(3)秸秆保留作为覆盖物的零耕作（ZT+RM），(4)秸秆加入的CT （CT+RI）和(5)稻渣焚烧后的CT （CT+RB）经过三年的稻麦种植系统试验。P的吸附-解吸符合准二级动力学(R2>；0.99)和Freundlich等温线(R2>；0.95)所有的处理和温度。Freundlich吸附量（KFads）随土壤理化性质的变化而变化，在15、25、35和45 ± 1°C条件下分别为10.9 ~ 28.5、14.3 ~ 32.2、18.3 ~ 40.2和22.5 ~ 56.5 μg1−ng−1mLn。P的吸附顺序为：CT+ 生物炭>； CT+RB >； ZT+RM >； CT+RI >； CT- r，与温度无关。热力学参数显示了可行的、自发的和吸热的过程，表明通过物理吸附。在原位秸秆管理土壤中，氢键是主要机制。在实验温度下，CT+ 生物炭、CT+ RB、ZT+RM、CT+RI、CT- r处理的Freundlich解吸系数（KFdes）分别为54.8 ~ 85.2、39.9 ~ 60.8、23.4 ~ 37.0、29.6 ~ 45.7和19.4 ~ 36.7 μg1−ng−1mLn，且均大于吸附。解吸顺序为：CT- r >； CT+RI >； ZT+RM >； CT+ RB>； CT+ 生物炭。秸秆原位处理（CT+生物炭、CT+RB和ZT+RM）对磷的吸附比CT- r和CT+ RI更大，解吸更慢，特别是CT+ 生物炭与CT- r相比，将导致更多的磷滞留在土壤基质中，从而防止富营养化和地表水的恶化。

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引用次数: 0

Understanding the molecular mechanisms of interactions between biochar and denitrifiers in N₂O emissions reduction: Pathway to more economical and sustainable fertilizers 了解生物炭和反硝化菌在减少二氧化碳排放中的相互作用的分子机制：通往更经济和可持续肥料的途径

IF 6.1 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2024-12-09 DOI: 10.1016/j.still.2024.106405

Babak Minofar , Nevena Milčić , Josef Maroušek , Beata Gavurová , Anna Maroušková

Biochar application to topsoil has been repeatedly and independently reported to reduce N₂O emissions, yet the underlying mechanisms remain poorly understood. This study hypothesizes that biochar enhances the stability and catalytic activity of N₂O reductase enzymes in denitrifying bacteria, promoting the conversion of N₂O to N₂ during denitrification. Interactions between biochar and the N₂O reductase enzyme (PsN₂OR) from the denitrifying bacterium Pseudomonas stutzeri were investigated through molecular dynamics simulations. The obtained results firstly revealed that biochar stabilizes this periplasmic enzyme in the aqueous solution via hydrophobic and hydrophilic interactions. Specifically, π–π stacking and hydrophobic interactions reduce the thermal fluctuations of hydrophobic amino acids, lowering entropy and improving enzymatic efficiency. Additionally, biochar adsorbs N₂O molecules, facilitating their delivery to the active site of the enzyme and enhancing the reaction rate. Deeper understandings of molecular interactions open new pathways in developing biochar-based fertilizers with slower, more economically and more environmentally favorable release of nutrients. This new type of fertilizers creates new opportunities for the biochar market, positioning it as a valuable tool for carbon sequestration and the mitigation of N₂O emissions.

生物炭在表土上的应用已经多次被独立报道可以减少N2O的排放，但其潜在的机制仍然知之甚少。本研究假设生物炭提高了反硝化细菌中N2O还原酶的稳定性和催化活性，促进了反硝化过程中N2O向N2的转化。通过分子动力学模拟研究了生物炭与反硝化细菌stutzeri假单胞菌N2O还原酶（PsN2OR）的相互作用。得到的结果首次揭示了生物炭通过疏水和亲水性相互作用在水溶液中稳定该酶。具体来说，π -π堆叠和疏水相互作用减少了疏水氨基酸的热波动，降低了熵，提高了酶效率。此外，生物炭吸附N2O分子，促进其传递到酶的活性位点，提高反应速率。对分子相互作用的深入理解为开发更慢、更经济、更环保的生物炭基肥料开辟了新的途径。这种新型肥料为生物炭市场创造了新的机会，将其定位为固碳和减少二氧化碳排放的宝贵工具。

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引用次数: 0

Effects of drying-induced shrinkage on thermal and hydraulic properties of clayey soils 干缩对粘性土热水力特性的影响

IF 6.1 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2024-12-09 DOI: 10.1016/j.still.2024.106415

Zhengchao Tian , Mouhui Zhang , Jiazhou Chen , Thorsten Knappenberger

The shrinkage and swelling phenomenon of clayey soils induces substantial effects on measurement and modeling of soil thermal and hydraulic properties. This study developed a combined heat-pulse and evaporation method for simultaneous measurement of soil deformation, thermal, and hydraulic properties of clayey soils during drying-shrinkage processes. Four clayey soils with different textures and initial bulk densities (ρ_b) were subjected to evaporative-drying experiments. The results showed that the shrinkage process significantly altered the soil pore structure, water-holding capacity, and hydraulic conductivity. Neglecting the soil volume change during drying led to an underestimation of soil water retention, with maximum biases of 0.05–0.09 cm³ cm⁻³ in the water content (θ) at the same metric potential, and resulted in errors spanning several orders of magnitude in hydraulic conductivity at the same θ condition. The soil thermal properties, including volumetric heat capacity (C), thermal conductivity (λ), and thermal diffusivity (α), exhibited distinct trends with changing θ and ρ_b compared to rigid soils. The C showed strong positive linear correlations with the θ, but the slopes were lower than those for rigid soils due to the offsetting effect of increasing ρ_b. The λ first increased and then decreased with the increasing θ, in contrast to the monotonic increase observed in rigid soils. The α had a strong negative linear relationship with the θ, contrary to the typical positive correlation in rigid soils. Meanwhile, effects of the changing ρ_b on the thermal properties were opposite than did the variation in θ. The findings highlight the importance of considering soil volume change when characterizing the coupled water-heat transport processes in expansive clayey soils. The developed method provides a useful tool for investigating the complex interactions between soil deformation, thermal and hydraulic properties during drying-wetting cycles.

粘性土的收缩和膨胀现象会对土壤热力和水力特性的测量和建模产生重大影响。本研究开发了一种热脉冲和蒸发相结合的方法，用于同时测量粘性土在干燥-收缩过程中的土壤变形、热和水力特性。对四种不同质地和初始容重（ρb）的粘性土壤进行了蒸发干燥实验。结果表明，收缩过程极大地改变了土壤的孔隙结构、持水能力和导水率。忽略干燥过程中土壤体积的变化会导致土壤保水性被低估，在相同公势下，土壤含水量（θ）的最大偏差为 0.05-0.09 cm3 cm-3，而在θ相同的条件下，土壤导水性的误差会达到几个数量级。与刚性土壤相比，随着 θ 和 ρb 的变化，包括体积热容 (C)、热导率 (λ) 和热扩散率 (α)在内的土壤热特性呈现出明显的变化趋势。C 与 θ 呈很强的正线性相关，但由于 ρb 增加的抵消效应，其斜率低于刚性土壤。随着 θ 的增大，λ 先增大后减小，这与刚性土壤中观察到的单调增大不同。α 与 θ 呈强烈的负线性关系，与刚性土壤中典型的正相关关系相反。同时，ρb 的变化对热特性的影响与 θ 的变化相反。研究结果突出表明，在表征膨胀性粘性土的水热耦合传输过程时，考虑土壤体积变化非常重要。所开发的方法为研究干燥-湿润循环过程中土壤变形、热和水力特性之间复杂的相互作用提供了有用的工具。

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引用次数: 0

Organic fertilizer substitution increased soil organic carbon through the association of microbial necromass C with iron oxides 有机肥替代通过微生物坏死体C与氧化铁的关联增加了土壤有机碳

IF 6.1 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2024-12-07 DOI: 10.1016/j.still.2024.106402

Yinan Xu , Jing Sheng , Liping Zhang , Guofeng Sun , Jianchu Zheng

Organic fertilizer was widely used to enhance the buildup of soil organic carbon (SOC) and microbial necromass C. Iron and aluminum (Fe/Al) oxides serve as critical factors influencing SOC by controlling microbial necromass C. Nevertheless, the alterations and dynamics of microbial necromass C alongside Fe/Al oxides in the presence of organic fertilizer remain poorly elucidated. To evaluate the effect of organic fertilizer substitution for chemical fertilizer on Fe/Al oxides and its relationship to microbial necromass C, a site experiment was initiated in 2010 including three treatments: chemical fertilizer (CF), 50 %CF+ 50 % organic fertilizer (50 % OF), and 100 % organic fertilizer (100 %OF). The data were collected after 4, 8, and 13 years of experiments in 2014, 2018, and 2023, respectively. The results showed that organic fertilizer substitution decreased C loss from microbial mineralization and increased microbial necromass C, and thus contributed to SOC accumulation. With experiment duration, SOC content did not increase from 2018 to 2023 under 100 %OF may be due to C saturation, while microbial necromass still had an increasing trend. In 2023, bacterial and fungal necromass C was increased by 157.4 % and 178.5 % under 50 %OF, and by 230.7 % and 337.8 % under 100 %OF compared with CF, respectively. This suggests that prolonged use of organic fertilizer can enhance the stable SOC. Organic fertilizer increased microbial necromass C mainly through promoting the formation of Fe/Al oxides, and Fe oxides had a more important effect than Al oxides. Overall, we concluded that organic fertilizer substitution increased stable SOC sequestration through the association of microbial necromass C with iron oxides.

有机肥被广泛用于提高土壤有机碳（SOC）和微生物坏死物C的积累。铁和铝（Fe/Al）氧化物通过控制微生物坏死物C而成为影响土壤有机碳（SOC）的关键因素。然而，有机肥存在下微生物坏死物C随Fe/Al氧化物的变化和动态尚不清楚。为评价有机肥替代化肥对Fe/Al氧化物的影响及其与微生物死亡菌群C的关系，于2010年开展了化肥、50% %CF+ 50 %有机肥（50 % of）和100% %有机肥（100 % of） 3种处理的现场试验。这些数据是在2014年、2018年和2023年分别进行了4年、8年和13年的实验后收集的。结果表明，有机肥替代减少了微生物矿化造成的碳损失，增加了微生物坏死团C，从而促进了有机碳的积累。随着试验时间的延长，2018 - 2023年土壤有机碳含量在100 %OF下没有增加，可能是由于碳饱和，而微生物坏死块仍有增加的趋势。2023年，与CF相比，在50 %OF下，细菌和真菌坏死团C分别增加了157.4 %和178.5 %；在100 %OF下，细菌和真菌坏死团C分别增加了230.7 %和337.8 %。说明长期施用有机肥可以提高土壤的稳定有机碳。有机肥增加微生物坏死团C主要是通过促进Fe/Al氧化物的形成，且Fe氧化物的作用比Al氧化物更重要。总的来说，我们得出结论，有机肥替代通过微生物坏死团C与氧化铁的关联增加了稳定的有机碳固存。

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引用次数: 0

Straw return combined with potassium fertilization improves potassium stocks in large-macroaggregates by increasing complex iron oxide under rice–oilseed rape rotation system 水稻-油菜轮作条件下，秸秆还田配施钾肥通过增加复合氧化铁来提高大-大团聚体钾储量

IF 6.1 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2024-12-07 DOI: 10.1016/j.still.2024.106404

Zhihao Xiong , Ziyi Gao , Jianwei Lu , Yangyang Zhang , Xiaokun Li

Potassium (K) supplementation strategies are required to enhance farm productivity in rice-upland rotations, where intensive cultivation practices often result in K deficiencies. Straw return improves the adsorption of K by increasing the content of soil humic acid in macroaggregates. Iron/aluminium (Fe/Al) oxides promote soil organic carbon storage and aggregate stability by acting as binding agents. However, limited information is available on the effects of Fe/Al oxides on the distribution of aggregate-associated K stocks. A field experiment was performed in the Yangtze River Basin, an area with low K stemming from intensive cultivation, with four fertilization treatments: inorganic nitrogen-phosphorus fertilizer (NP), (NPK), inorganic NP with straw return (NP+St), and inorganic NPK with straw return (NPK+St). Results showed that the straw return (NP+St), K fertilization (NPK) and the combination of both (NPK+St) increased soil exchangeable K content (EK) by 32.6 %, 23.7 % and 53.6 % in the rice season, respectively, and increased by 49.9 %, 25.5 % and 182.0 % in the oilseed rape season, respectively, compared with that of no K addition (NP) treatment. K stocks in macroaggregates accounted for more than 90 % of the total K stocks in all treatments. Straw return and K fertilization increased EK and non-exchangeable K (NEK) stocks in large-macroaggregates (>2 mm) by increasing the aggregate-associated K content and regulating the abundance of aggregate. Redundancy analysis showed that complex iron oxide (Fep) was one of the main factors influencing soil available K. The NP+St and NPK+St treatments increased the proportion of particle size and K stocks by increasing the Fep content in large-macroaggregates. Pearson’s correlation analysis and random forest model analysis indicated that EK and NEK stocks in the large-macroaggregates were positively correlated with K uptake by rice and oilseed rape, which suggested that they were key factors influencing K uptake. Therefore, straw return increased Fep in large-macroaggregates to expand the K stock in soil and K uptake by crops under this field experiment conditions. Our results provided new insights with implications for improving soil K availability by straw return combined with K fertilization.

在水稻旱地轮作中，需要采取补钾策略来提高农业生产率，在旱地轮作中，精耕细作常常导致缺钾。秸秆还田通过增加土壤大团聚体中腐植酸的含量来促进对钾的吸附。铁/铝（Fe/Al）氧化物作为结合剂促进土壤有机碳的储存和团聚体的稳定性。然而，关于铁/铝氧化物对团聚体相关K元素分布的影响的信息有限。在长江流域精耕细作低钾地区，采用无机氮磷肥（NP）、无机氮磷肥（NPK）、无机氮磷肥配合秸秆还田（NP+St）和无机氮磷肥配合秸秆还田（NPK+St） 4种施肥处理进行田间试验。结果表明，秸秆还田（NP+St）、氮磷钾（NPK）及两者配施（NPK+St）在水稻季分别使土壤交换态钾含量（EK）提高了32.6 %、23.7 %和53.6 %，在油菜季分别比不施钾（NP）处理提高了49.9 %、25.5 %和182.0 %。各处理大团聚体K储量占总K储量的90% %以上。秸秆还田和施钾通过增加团聚体相关钾含量和调节团聚体丰度，增加了大-宏观团聚体（>2 mm）中EK和NEK储量。冗余分析表明，复合氧化铁（Fep）是影响土壤速效钾的主要因素之一。NP+St和NPK+St处理通过提高大团聚体中Fep含量，提高了粒径和K储量的比例。Pearson相关分析和随机森林模型分析表明，大-宏观团聚体中EK和NEK储量与水稻和油菜的钾吸收呈显著正相关，是影响钾吸收的关键因素。因此，在本大田试验条件下，秸秆还田增加了大-宏观团聚体Fep，扩大了土壤钾储量和作物对钾的吸收。本研究结果为秸秆还田配施钾肥提高土壤钾有效性提供了新的思路和启示。

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引用次数: 0

Comparing WEPP with USLE based models: The role of bare fallow runoff and soil loss plots WEPP与基于USLE模型的比较：裸休耕地径流和土壤流失地的作用

IF 6.1 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2024-12-06 DOI: 10.1016/j.still.2024.106413

P.I.A. Kinnell

There are many soil erosion models and model applications. However, as a general rule, models of rainfall erosion cannot fully model the complexity of the detachment and transport processes involved in soil erosion by rain so that it is crucial that soil erosion models are tested against experimental data. In developing the USLE, the designers recognised that the fundamental ability of a model to predict erosion in croplands began with its ability to account for soil losses from bare fallow areas under natural rainfall. Given this, any event-based model perceived to be a replacement for USLE-based models should be first tested for its ability to account for event soil losses from bare fallow areas under natural rain. Comparisons between the abilities of WEPP, RUSLE2 and the USLE-M to account for event soil loss on bare fallow runoff and soil loss plots leads to questions about the capacity of WEPP to model erosion on areas where some storms produce rills but others do not. One reason for this may lie in the fact that, in WEPP, sediment produced by raindrop-driven erosion is moved by flow-driven sediment transport to the outlet in situations where flow-driven sediment transport in channels does not occur. The modelling approach adopted by the designers of the USLE requires the veracity of any alternative erosion model to be established on bare fallow runoff and soil loss plots before focusing on erosion on vegetated areas.

土壤侵蚀模型及其应用有很多。然而，一般来说，降雨侵蚀模型不能完全模拟降雨侵蚀所涉及的剥离和输运过程的复杂性，因此用实验数据对土壤侵蚀模型进行检验是至关重要的。在开发USLE的过程中，设计师认识到模型预测农田侵蚀的基本能力始于它在自然降雨下光秃秃的休耕地区的土壤流失的能力。鉴于此，任何基于事件的模型被认为是基于usle的模型的替代品，都应该首先测试其考虑自然降雨下光秃秃的休耕地区的事件土壤损失的能力。通过比较WEPP、RUSLE2和USLE-M对休耕径流和土壤流失区的事件土壤流失的能力，人们对WEPP在一些风暴产生细沟而另一些风暴没有产生细沟的地区模拟侵蚀的能力提出了质疑。其中一个原因可能是，在WEPP中，雨滴驱动侵蚀产生的泥沙在河道中不发生流驱动输沙的情况下，通过流驱动输沙向出口移动。USLE设计者采用的建模方法要求在关注植被地区的侵蚀之前，在光秃秃的休耕径流和土壤流失地块上建立任何替代侵蚀模型的准确性。

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引用次数: 0

Evaluation of nutrient spatial distribution and heavy metal pollution improvement in small-scale farmland under the action of biochar and microbial organic fertilizer 生物炭与微生物有机肥作用下小农农田养分空间分布及重金属污染改善评价

IF 6.1 1区农林科学 Q1 SOIL SCIENCE

Soil & Tillage Research

Pub Date : 2024-12-06 DOI: 10.1016/j.still.2024.106386

Zhenyu He , Bo Kang , Leiyu Feng , Yonggao Yin , Jie Yang , Guiqiang Liu , Fusheng Zha

Currently, China is undergoing reforms in its rural land transfer policy. As a traditional agricultural country, the operation and management of small-scale farmland serve as the primary economic source for Chinese farmers. However, small-scale farmland is vulnerable to external influences and lacks sufficient risk-resistance capabilities. Developing a low-cost, long-term improvement model is essential for enhancing small-scale farmland.This paper explores the direct integration of biochar and microbial organic fertilizer into the cultivation process of heavy metal-contaminated farmland. The results indicate that the combined application of biochar and microbial organic fertilizer increased soil fertility by 161 % and enhanced the abundance of the antagonistic Chaetomiaceae by 31.6 %. Geostatistical simulations revealed low variation in soil pH, while fertility and water content exhibited high variability. Furthermore, the partial least squares path model confirmed that biochar and organic fertilizer promote.This study elucidates the improvement mechanisms facilitated by biochar and microbial organic fertilizer, providing valuable insights for the management of small-scale farmland in the context of agricultural reform in China.

当前，中国正在进行农村土地流转政策改革。作为一个传统的农业国家，小规模农田的经营管理是中国农民的主要经济来源。然而，小规模农田易受外界影响，缺乏足够的抗风险能力。开发一种低成本、长期的改良模式对于改善小规模农田至关重要。探索将生物炭与微生物有机肥直接整合到重金属污染农田的耕作过程中。结果表明，生物炭与微生物有机肥配施可使土壤肥力提高161 %，拮抗毛藻科植物丰度提高31.6% %。地质统计模拟结果显示，土壤pH值变化不大，而肥力和水分含量变化较大。此外，偏最小二乘路径模型也证实了生物炭和有机肥对土壤养分的促进作用。本研究阐明了生物炭和微生物有机肥对土壤的改善机制，为中国农业改革背景下的小规模农田管理提供了有价值的见解。

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引用次数: 0