Pub Date : 2024-11-16DOI: 10.1016/j.ejsobi.2024.103695
Yuxuan Zhang , Mengya Lu , Zhiquan Wang , Kun Zhang , Bin Zhang , Reziwanguli Naimaiti , Shangyuan Wei , Xueli Ding
Straw return accelerates the decomposition of soil organic C (SOC), a phenomenon referred to as the priming effect. However, the interactive influence of nutrient supply levels on priming effect intensity and SOC sequestration in paddy soils still needs to be better understood. In this study, we investigated the dynamics of the priming effect and associated changes in phospholipid fatty acids, enzyme activity, and microbial necromass following the addition of 13C-labelled rice straw (98 % atom) to soils under three nutrient supply levels during a 300-d incubation period. Our results showed that the addition of straw (5 g C kg−1 soil) with no-nutrient (S + Nu0), low nutrient (S + Nulow, 42 mg N kg−1, 10 mg P kg−1), and high nutrient (S + Nuhigh, 126 mg N kg−1, 30 mg P kg−1) supply increased total CO2 production by 42.9 %, 59.0 %, and 97.3 %, respectively, compared to the control soil. After 300 d, the cumulative priming effect was nearly doubled in the S + Nulow and tripled in the S + Nuhigh compared to the S + Nu0. Moreover, the intensity of priming varied with the incubation stage under nutrient treatments. Similar patterns of priming effect were observed across all straw amendments during the early incubation stages; however, the priming effect increased with the nutrient supply levels in the later stages. These patterns are linked to microbial metabolic limitation and resource acquisition strategies, as evidenced by a lower C-to-N stoichiometry of extracellular enzymes and necromass in the S + Nulow S + Nuhigh. A greater proportion of straw-derived C incorporation into SOC (indicated by higher levels 13C-SOC) in nutrient-enriched was found, which largely offset the native SOC losses, resulting in high SOC content by the end of incubation. Our findings highlight the critical role of nutrient supply in regulating the priming effect and the balance of SOC after straw return in paddy soils.
秸秆还田可加速土壤有机碳（SOC）的分解，这种现象被称为引诱效应。然而，养分供应水平对稻田土壤引诱效应强度和 SOC 固碳的交互影响仍有待进一步了解。在本研究中，我们研究了在三种养分供应水平下的土壤中添加 13C 标记的稻草（原子含量为 98%）后，在 300 天的培养期内引诱效应的动态变化以及磷脂脂肪酸、酶活性和微生物坏死物质的相关变化。结果表明，与对照土壤相比，在无养分（S + Nu0）、低养分（S + Nulow，42 mg N kg-1，10 mg P kg-1）和高养分（S + Nuhigh，126 mg N kg-1，30 mg P kg-1）条件下添加稻草（5 g C kg-1 土壤）可使二氧化碳总产量分别增加 42.9%、59.0% 和 97.3%。300 d 后，与 S + Nu0 相比，S + Nulow 的累积引诱效果几乎翻了一番，S + Nuhigh 的累积引诱效果则翻了三番。此外，在营养处理下，引诱作用的强度随培养阶段的不同而变化。在早期培养阶段，所有秸秆改良剂都观察到了类似的引诱效应模式；然而，在后期阶段，引诱效应随着营养供应水平的提高而增加。这些模式与微生物的代谢限制和资源获取策略有关，S + Nulow S + Nuhigh 中细胞外酶和坏死物质的 C-N 比化学计量较低就是证明。在营养丰富的情况下，秸秆衍生的碳有更大比例掺入 SOC（13C-SOC 含量更高），这在很大程度上抵消了原生 SOC 的损失，导致培养结束时 SOC 含量较高。我们的研究结果突显了养分供应在调节稻田土壤秸秆还田后的引诱效应和 SOC 平衡中的关键作用。
{"title":"Nutrient supply enhances positive priming of soil organic C under straw amendment and accelerates the incorporation of straw-derived C into organic C pool in paddy soils","authors":"Yuxuan Zhang , Mengya Lu , Zhiquan Wang , Kun Zhang , Bin Zhang , Reziwanguli Naimaiti , Shangyuan Wei , Xueli Ding","doi":"10.1016/j.ejsobi.2024.103695","DOIUrl":"10.1016/j.ejsobi.2024.103695","url":null,"abstract":"<div><div>Straw return accelerates the decomposition of soil organic C (SOC), a phenomenon referred to as the priming effect. However, the interactive influence of nutrient supply levels on priming effect intensity and SOC sequestration in paddy soils still needs to be better understood. In this study, we investigated the dynamics of the priming effect and associated changes in phospholipid fatty acids, enzyme activity, and microbial necromass following the addition of <sup>13</sup>C-labelled rice straw (98 % atom) to soils under three nutrient supply levels during a 300-d incubation period. Our results showed that the addition of straw (5 g C kg<sup>−1</sup> soil) with no-nutrient (S + Nu<sub>0</sub>), low nutrient (S + Nu<sub>low</sub>, 42 mg N kg<sup>−1</sup>, 10 mg P kg<sup>−1</sup>), and high nutrient (S + Nu<sub>high</sub>, 126 mg N kg<sup>−1</sup>, 30 mg P kg<sup>−1</sup>) supply increased total CO<sub>2</sub> production by 42.9 %, 59.0 %, and 97.3 %, respectively, compared to the control soil. After 300 d, the cumulative priming effect was nearly doubled in the S + Nu<sub>low</sub> and tripled in the S + Nu<sub>high</sub> compared to the S + Nu<sub>0</sub>. Moreover, the intensity of priming varied with the incubation stage under nutrient treatments. Similar patterns of priming effect were observed across all straw amendments during the early incubation stages; however, the priming effect increased with the nutrient supply levels in the later stages. These patterns are linked to microbial metabolic limitation and resource acquisition strategies, as evidenced by a lower C-to-N stoichiometry of extracellular enzymes and necromass in the S + Nu<sub>low</sub> S + Nu<sub>high</sub>. A greater proportion of straw-derived C incorporation into SOC (indicated by higher levels <sup>13</sup>C-SOC) in nutrient-enriched was found, which largely offset the native SOC losses, resulting in high SOC content by the end of incubation. Our findings highlight the critical role of nutrient supply in regulating the priming effect and the balance of SOC after straw return in paddy soils.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103695"},"PeriodicalIF":3.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-16DOI: 10.1016/j.ejsobi.2024.103694
Hao Wang , JinPing Chen , Mingxue Du , Yihao Ruan , Jiameng Guo , Ruixin Shao , Yongchao Wang , Qinghua Yang
Carbohydrate-active enzymes (CAZymes) play a crucial role in plant-derived carbon utilization and decomposition and are influenced by the crop rotation system; however, our knowledge of how different agricultural systems impact CAZyme functionality is still limited. We conducted a metagenomic analysis to evaluate the functional genes of CAZymes in a 12-year in situ farmland with three commonly used crop rotation systems: wheat-maize rotation (WM), wheat-cotton rotation (WC), and wheat-soybean rotation (WS). We aimed to study the impact of long-term use of crop rotation, especially crop rotation involving soybean, on soil organic carbon (SOC) content and to gain an in-depth understanding of the CAZyme genes in context of the disparities in SOC. After 12 years, the SOC content was significantly higher in WS than in WC (5.44 %) and WM (17.6 %). Furthermore, the crop rotation system had a significant effect on the soil microbial communities and CAZyme function genes. Detailly, WS increased the phyla abundance of Proteobacteria, Actinobacteria, and Firmicutes and enriched the glycoside hydrolase (GH) and carbohydrate-binding modules (CBM) genes; WC increased the abundance of Acidobacteria and Bacteroidota and enriched the polysaccharide lyase gene; WM increased the abundance of Nitrospirae, Candidatus_Rokubacteria, Chloroflexi and Gemmatimonadetes and enriched the gene abundance of glycosyltransferases and auxiliary activity genes. Additionally, Acidobacteria, Proteobacteria, and Actinobacteria are key phyla involved in soil carbon cycling and collectively contribute >70 % of the total CAZyme functional genes, which highlights their importance. In addition, our results indicated that total nitrogen content played a major role in influencing genes related to CAZymes, especially those belonging to the GH family. Our study demonstrates that WS conferred the advantage of increasing SOC across the three crop rotation systems. CAZyme analysis revealed that WS's could potentially support the increased abundance of Proteobacteria, Actinobacteria and Firmicutes in the soil community, at the same time potentially leading to increased number of GH and CBM genes in the soil, which may bolster the decomposition and transformation of plant-derived carbon, thus promoting an increase in SOC content. The findings of this study offer new insights into the microbial factors contributing to SOC enhancement in rotation systems.
{"title":"In-depth insights into carbohydrate-active enzyme genes regarding the disparities in soil organic carbon after 12-year rotational cropping system field study","authors":"Hao Wang , JinPing Chen , Mingxue Du , Yihao Ruan , Jiameng Guo , Ruixin Shao , Yongchao Wang , Qinghua Yang","doi":"10.1016/j.ejsobi.2024.103694","DOIUrl":"10.1016/j.ejsobi.2024.103694","url":null,"abstract":"<div><div>Carbohydrate-active enzymes (CAZymes) play a crucial role in plant-derived carbon utilization and decomposition and are influenced by the crop rotation system; however, our knowledge of how different agricultural systems impact CAZyme functionality is still limited. We conducted a metagenomic analysis to evaluate the functional genes of CAZymes in a 12-year in situ farmland with three commonly used crop rotation systems: wheat-maize rotation (WM), wheat-cotton rotation (WC), and wheat-soybean rotation (WS). We aimed to study the impact of long-term use of crop rotation, especially crop rotation involving soybean, on soil organic carbon (SOC) content and to gain an in-depth understanding of the CAZyme genes in context of the disparities in SOC. After 12 years, the SOC content was significantly higher in WS than in WC (5.44 %) and WM (17.6 %). Furthermore, the crop rotation system had a significant effect on the soil microbial communities and CAZyme function genes. Detailly, WS increased the phyla abundance of <em>Proteobacteria</em>, <em>Actinobacteria</em>, and <em>Firmicutes</em> and enriched the glycoside hydrolase (GH) and carbohydrate-binding modules (CBM) genes; WC increased the abundance of <em>Acidobacteria</em> and <em>Bacteroidota</em> and enriched the polysaccharide lyase gene; WM increased the abundance of <em>Nitrospirae</em>, <em>Candidatus_Rokubacteria</em>, <em>Chloroflexi</em> and <em>Gemmatimonadetes</em> and enriched the gene abundance of glycosyltransferases and auxiliary activity genes. Additionally, <em>Acidobacteria</em>, <em>Proteobacteria</em>, and <em>Actinobacteria</em> are key phyla involved in soil carbon cycling and collectively contribute >70 % of the total CAZyme functional genes, which highlights their importance. In addition, our results indicated that total nitrogen content played a major role in influencing genes related to CAZymes, especially those belonging to the GH family. Our study demonstrates that WS conferred the advantage of increasing SOC across the three crop rotation systems. CAZyme analysis revealed that WS's could potentially support the increased abundance of <em>Proteobacteria</em>, <em>Actinobacteria</em> and <em>Firmicutes</em> in the soil community, at the same time potentially leading to increased number of GH and CBM genes in the soil, which may bolster the decomposition and transformation of plant-derived carbon, thus promoting an increase in SOC content. The findings of this study offer new insights into the microbial factors contributing to SOC enhancement in rotation systems.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103694"},"PeriodicalIF":3.7,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142652448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-06DOI: 10.1016/j.ejsobi.2024.103692
Danni Li , Yi Li , Shuihong Yao , Hu Zhou , Shan Huang , Xianlong Peng , Yili Meng
Soil pore distribution influences the permeability of gas, water, and solutes, affecting microbial activities such as nitrogen (N) mineralization. Understanding its impact on N mineralization and the subsequent N transformations is essential for managing compacted paddy soils. This study conducted incubation experiments on two paddy soils from typical Chinese rice regions, Northeastern meadow chernozemic Mollisols, and Southern umbric Ferralsols, under three bulk densities (1.0 g cm−3, 1.2 g cm−3, and 1.4 g cm−3) to investigate the effects of soil porosity on N mineralization and N cycling functional genes. Although the cumulative mineralized N showed no significant difference, with increased macropores (>100 μm) and mesopores (30–100 μm), Ferralsols exhibited a significantly higher net N mineralization rate from day 0 to day 7, while Mollisols extended the mineralization after day 21. Soil dissolved organic carbon (DOC) had a similar temporal trend to the net N mineralization rate, suggesting DOC was the product of mineralization. Soil microbial biomass carbon (MBC) showed an opposite temporal trend to the net N mineralization rate in Mollisols, suggesting microbial biomass as a key N source for mineralization. Soil pores distribution did not affect nitrification under waterlogged conditions, but it affected nirK, nirS and nosZ genes by altering redox potential and substrates availability in the pore micro-environment. Overall, soil pores over 30 μm were the key pore size ranges affecting the intensity and duration of N mineralization, with different effects on DOC, MBC, and N cycling functional genes in Mollisols and Ferralsols. These findings emphasized the role of pore size in regulating N transformation in waterlogged conditions, contributing to the understanding of the N availability in compacted paddy soils from typical geographic rice-growing regions.
{"title":"Dynamics of nitrogen mineralization and nitrogen cycling functional genes in response to soil pore size distribution","authors":"Danni Li , Yi Li , Shuihong Yao , Hu Zhou , Shan Huang , Xianlong Peng , Yili Meng","doi":"10.1016/j.ejsobi.2024.103692","DOIUrl":"10.1016/j.ejsobi.2024.103692","url":null,"abstract":"<div><div>Soil pore distribution influences the permeability of gas, water, and solutes, affecting microbial activities such as nitrogen (N) mineralization. Understanding its impact on N mineralization and the subsequent N transformations is essential for managing compacted paddy soils. This study conducted incubation experiments on two paddy soils from typical Chinese rice regions, Northeastern meadow chernozemic Mollisols, and Southern umbric Ferralsols, under three bulk densities (1.0 g cm<sup>−3</sup>, 1.2 g cm<sup>−3</sup>, and 1.4 g cm<sup>−3</sup>) to investigate the effects of soil porosity on N mineralization and N cycling functional genes. Although the cumulative mineralized N showed no significant difference, with increased macropores (>100 μm) and mesopores (30–100 μm), Ferralsols exhibited a significantly higher net N mineralization rate from day 0 to day 7, while Mollisols extended the mineralization after day 21. Soil dissolved organic carbon (DOC) had a similar temporal trend to the net N mineralization rate, suggesting DOC was the product of mineralization. Soil microbial biomass carbon (MBC) showed an opposite temporal trend to the net N mineralization rate in Mollisols, suggesting microbial biomass as a key N source for mineralization. Soil pores distribution did not affect nitrification under waterlogged conditions, but it affected <em>nirK</em>, <em>nirS</em> and <em>nosZ</em> genes by altering redox potential and substrates availability in the pore micro-environment. Overall, soil pores over 30 μm were the key pore size ranges affecting the intensity and duration of N mineralization, with different effects on DOC, MBC, and N cycling functional genes in Mollisols and Ferralsols. These findings emphasized the role of pore size in regulating N transformation in waterlogged conditions, contributing to the understanding of the N availability in compacted paddy soils from typical geographic rice-growing regions.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103692"},"PeriodicalIF":3.7,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-05DOI: 10.1016/j.ejsobi.2024.103690
Elena Kost , Dominika Kundel , Rafaela Feola Conz , Paul Mäder , Hans-Martin Krause , Johan Six , Jochen Mayer , Martin Hartmann
The impacts of climate change, such as drought, can affect soil microbial communities. These communities are crucial for soil functioning and crop production. Organic and conventional cropping systems can promote distinct soil microbiomes and soil organic carbon contents, which might generate different capacities to mitigate drought effects on these cropping systems. A field-scale drought simulation was performed in long-term organically and conventionally managed cropping systems differing in fertilization and pesticide application. The soil microbiome was assessed during and after drought in bulk soil, rhizosphere, and roots of wheat. We found that drought reduced soil respiration and altered microbial community structures, affecting fungi in the bulk soil and rhizosphere more strongly than prokaryotes. Microbial communities associated with crops (i.e. rhizosphere and root) were more strongly influenced by drought compared to bulk soil communities. Drought legacy effects were observed in the bulk soil after harvesting and rewetting. The extent of the structural shifts in the soil microbiome in response to severe drought did not differ significantly between the organic and conventional cropping systems but each cropping system maintained a unique microbiome under drought. All cropping systems showed relative increases in potential plant growth-promoting genera under drought but some genera such as Streptomyces, Rhizophagus, Actinomadura, and Aneurinibacillus showed system-specific drought responses. This agricultural field study indicated that fungal communities might be less resistant to drought than prokaryotic communities in cropping systems and these effects get more pronounced in closer association with plants. Organic fertilization and the associated increase in soil organic carbon, or the reduction in pesticide application might not have the proposed ability to buffer severe drought stress on soil microbial taxonomic diversity. Yet, it remains to be elucidated whether the ability to maintain system-specific soil microbiomes also during drought translates into different functional capabilities to cope with the stress.
{"title":"Soil microbial resistance and resilience to drought under organic and conventional farming","authors":"Elena Kost , Dominika Kundel , Rafaela Feola Conz , Paul Mäder , Hans-Martin Krause , Johan Six , Jochen Mayer , Martin Hartmann","doi":"10.1016/j.ejsobi.2024.103690","DOIUrl":"10.1016/j.ejsobi.2024.103690","url":null,"abstract":"<div><div>The impacts of climate change, such as drought, can affect soil microbial communities. These communities are crucial for soil functioning and crop production. Organic and conventional cropping systems can promote distinct soil microbiomes and soil organic carbon contents, which might generate different capacities to mitigate drought effects on these cropping systems. A field-scale drought simulation was performed in long-term organically and conventionally managed cropping systems differing in fertilization and pesticide application. The soil microbiome was assessed during and after drought in bulk soil, rhizosphere, and roots of wheat. We found that drought reduced soil respiration and altered microbial community structures, affecting fungi in the bulk soil and rhizosphere more strongly than prokaryotes. Microbial communities associated with crops (i.e. rhizosphere and root) were more strongly influenced by drought compared to bulk soil communities. Drought legacy effects were observed in the bulk soil after harvesting and rewetting. The extent of the structural shifts in the soil microbiome in response to severe drought did not differ significantly between the organic and conventional cropping systems but each cropping system maintained a unique microbiome under drought. All cropping systems showed relative increases in potential plant growth-promoting genera under drought but some genera such as <em>Streptomyces</em>, <em>Rhizophagus, Actinomadura</em>, and <em>Aneurinibacillus</em> showed system-specific drought responses. This agricultural field study indicated that fungal communities might be less resistant to drought than prokaryotic communities in cropping systems and these effects get more pronounced in closer association with plants. Organic fertilization and the associated increase in soil organic carbon, or the reduction in pesticide application might not have the proposed ability to buffer severe drought stress on soil microbial taxonomic diversity. Yet, it remains to be elucidated whether the ability to maintain system-specific soil microbiomes also during drought translates into different functional capabilities to cope with the stress.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103690"},"PeriodicalIF":3.7,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142587210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-03DOI: 10.1016/j.ejsobi.2024.103691
Min Wang , Chang Liao , Weili Lai , Songyi Huang , Shihong Xiao , Caiqiong Deng , Xianhua Gan , Qing Ma , Mengyun Liu
<div><h3>Context</h3><div>Stand conversion in subtropical regions has altered soil physicochemical properties and microbial communities, leading to changes in microbially mediated processes, such as microbial necromass C (MNC) formation and accumulation. However, previous studies on the effects of stand conversion on MNC are lacking, leading to gaps in our understanding regarding the influence of long-term stand conversion on MNC accumulation in different soil layers and the relative importance of soil properties for regulating MNC.</div></div><div><h3>Aims</h3><div>In this study, we used field surveys and soil analysis to assess the effects of converting a <em>Eucalyptus</em> forest into other planted forest (broadleaf mixed forest [BM] and <em>Acacia mangium</em> × <em>Acacia auriculiformis</em> forest [AM]) on soil properties, enzyme activity, microbial community composition, and MNC after conversion 20 years in Guangdong, South China.</div></div><div><h3>Results</h3><div>We found that the content of soil organic C (SOC) in the surface soil (0–10 cm after litter removal) increased by 64.9 % when <em>Eucalyptus</em> was converted to AM, whereas there was no significant difference in the subsurface soil (10–20 cm). β-1,4-glucosidase (BG) and β-1,4-N-acetaminophen glucosidase (NAG) activity increased significantly, while leucine aminopeptidase (LA) activity decreased significantly in the surface soil. In the subsurface soil, BG activity did not change significantly; nonetheless, acid phosphomonoesterase (AP) activity decreased. The fungal, bacterial, and gram-negative bacterial biomass did not significantly differ among the different forests in the surface soil, but the fungal, bacterial, gram-positive, and gram-negative bacterial biomass decreased significantly in the subsurface soil. The ratio of fungi to bacteria was highest in the BM, whereas the ratio of gram-positive to gram-negative bacteria was highest in the AM. Soil fungal and microbial necromass C and the ratio of fungal to bacterial necromass C increased significantly in the surface soil when <em>Eucalyptus</em> was converted to AM. The contribution of MNC and fungal necromass C to SOC content significantly increased by 22.20 % and 26.23 %, respectively, when <em>Eucalyptus</em> was converted to AM. The main controlling factors of MNC accumulation in the surface soil were pH and total N, whereas soil enzyme activity (BG related to C-acquisition) was the dominant determinant of MNC accumulation in the subsurface soil.</div></div><div><h3>Conclusion</h3><div>Our study provides evidence that converting <em>Eucalyptus</em> to AM may promote MNC accumulation in the surface soil by changing soil pH and TN content to affect soil enzyme activity and microbial community structure, and ultimately changed MNC accumulation. Therefore, developing effective forest management practices, such as reasonable stand conversion may help to enhance forest SOC accumulation by increasing MNC accumulation.</d
背景亚热带地区的林分转换改变了土壤理化性质和微生物群落，导致微生物介导的过程发生变化，如微生物坏死物质 C（MNC）的形成和积累。然而，以前缺乏有关林分转换对 MNC 影响的研究，导致我们对长期林分转换对不同土层中 MNC 积累的影响以及土壤特性对调节 MNC 的相对重要性的认识存在差距。目的 在本研究中，我们利用实地调查和土壤分析评估了在中国南方广东将桉树林改造成其他人工林（阔叶混交林 [BM] 和芒果相思树 × 金合欢林 [AM]）20 年后对土壤性质、酶活性、微生物群落组成和 MNC 的影响。结果我们发现，当桉树转化为 AM 后，表层土壤（去除枯落物后 0-10 厘米）的土壤有机碳（SOC）含量增加了 64.9%，而表层下土壤（10-20 厘米）则无显著差异。表层土壤中，β-1,4-葡萄糖苷酶（BG）和β-1,4-N-乙酰氨基酚葡萄糖苷酶（NAG）活性显著增加，而亮氨酸氨肽酶（LA）活性显著降低。在地下土壤中，BG 活性没有明显变化；但酸性磷单酯酶（AP）活性有所下降。在表层土壤中，不同森林的真菌、细菌和革兰氏阴性菌生物量没有显著差异，但在表层下土壤中，真菌、细菌、革兰氏阳性菌和革兰氏阴性菌生物量显著下降。真菌与细菌的比例在 BM 中最高，而革兰氏阳性菌与革兰氏阴性菌的比例在 AM 中最高。当桉树转化为 AM 时，表层土壤中的土壤真菌和微生物坏死物质 C 以及真菌与细菌坏死物质 C 之比显著增加。桉树转化为 AM 后，MNC 和真菌坏死物质 C 对 SOC 含量的贡献率分别大幅增加了 22.20 % 和 26.23 %。表层土壤中 MNC 积累的主要控制因素是 pH 值和全氮，而土壤酶活性（与 C 获取有关的 BG）是表层下土壤中 MNC 积累的主要决定因素。因此，制定有效的森林管理措施，如合理的林分转换，可能有助于通过增加 MNC 积累来提高森林 SOC 积累。
{"title":"Plantation conversion of Eucalyptus promotes soil microbial necromass C accumulation","authors":"Min Wang , Chang Liao , Weili Lai , Songyi Huang , Shihong Xiao , Caiqiong Deng , Xianhua Gan , Qing Ma , Mengyun Liu","doi":"10.1016/j.ejsobi.2024.103691","DOIUrl":"10.1016/j.ejsobi.2024.103691","url":null,"abstract":"<div><h3>Context</h3><div>Stand conversion in subtropical regions has altered soil physicochemical properties and microbial communities, leading to changes in microbially mediated processes, such as microbial necromass C (MNC) formation and accumulation. However, previous studies on the effects of stand conversion on MNC are lacking, leading to gaps in our understanding regarding the influence of long-term stand conversion on MNC accumulation in different soil layers and the relative importance of soil properties for regulating MNC.</div></div><div><h3>Aims</h3><div>In this study, we used field surveys and soil analysis to assess the effects of converting a <em>Eucalyptus</em> forest into other planted forest (broadleaf mixed forest [BM] and <em>Acacia mangium</em> × <em>Acacia auriculiformis</em> forest [AM]) on soil properties, enzyme activity, microbial community composition, and MNC after conversion 20 years in Guangdong, South China.</div></div><div><h3>Results</h3><div>We found that the content of soil organic C (SOC) in the surface soil (0–10 cm after litter removal) increased by 64.9 % when <em>Eucalyptus</em> was converted to AM, whereas there was no significant difference in the subsurface soil (10–20 cm). β-1,4-glucosidase (BG) and β-1,4-N-acetaminophen glucosidase (NAG) activity increased significantly, while leucine aminopeptidase (LA) activity decreased significantly in the surface soil. In the subsurface soil, BG activity did not change significantly; nonetheless, acid phosphomonoesterase (AP) activity decreased. The fungal, bacterial, and gram-negative bacterial biomass did not significantly differ among the different forests in the surface soil, but the fungal, bacterial, gram-positive, and gram-negative bacterial biomass decreased significantly in the subsurface soil. The ratio of fungi to bacteria was highest in the BM, whereas the ratio of gram-positive to gram-negative bacteria was highest in the AM. Soil fungal and microbial necromass C and the ratio of fungal to bacterial necromass C increased significantly in the surface soil when <em>Eucalyptus</em> was converted to AM. The contribution of MNC and fungal necromass C to SOC content significantly increased by 22.20 % and 26.23 %, respectively, when <em>Eucalyptus</em> was converted to AM. The main controlling factors of MNC accumulation in the surface soil were pH and total N, whereas soil enzyme activity (BG related to C-acquisition) was the dominant determinant of MNC accumulation in the subsurface soil.</div></div><div><h3>Conclusion</h3><div>Our study provides evidence that converting <em>Eucalyptus</em> to AM may promote MNC accumulation in the surface soil by changing soil pH and TN content to affect soil enzyme activity and microbial community structure, and ultimately changed MNC accumulation. Therefore, developing effective forest management practices, such as reasonable stand conversion may help to enhance forest SOC accumulation by increasing MNC accumulation.</d","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103691"},"PeriodicalIF":3.7,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-24DOI: 10.1016/j.ejsobi.2024.103689
Ying Wang , Yimei Huang , Na Li , Qian Huang , Baorong Wang , Shaoshan An
Autotrophic microorganisms can fix carbon dioxide (CO2) into organic carbon (C), potentially offering a natural mechanism to mitigate global climate change. Forest soils, recognized as vast and critical C repositories with significant microbial CO2 fixation rates, remain understudied, particularly regarding the spatial variations of autotrophic bacteria and their relationship to soil functions in arid regions. In this study, we systematically investigated soil multifunctionality, along with the spatial distribution of autotrophic bacterial communities identified by the RubisCO cbbL and cbbM genes, and the driving factors across a longitudinal gradient in the Loess Plateau forest soils. The investigation spanned an ∼850 km west-east transect with precipitation below 600 mm. The alpha diversity of cbbL-containing bacteria, as measured by the Chao1 index, was correlated with climatic variables such as precipitation and elevation instead of local soil characteristics. In contrast, the alpha diversity of cbbM-containing bacteria was associated with soil properties. The community composition of autotrophic bacteria, based on cbbL and cbbM genes, showed greater similarity in soils from the eastern Loess Plateau and was distinct from those in the western region. The cbbL- and cbbM-containing generalist taxa were subject to differential selection and promotion between the eastern and western regions. Temperature, soil pH and spatial variables were key drivers influencing the community composition of cbbL- and cbbM-containing bacteria. The diversity and communities of soil autotrophic bacteria significantly affected soil multifunctionality. The study demonstrates that soil autotrophic bacteria in forest soils are intricately connected to climatic conditions, soil pH and spatial factors, significantly impacting soil multifunctionality. These insights provide evidence that can be instrumental in predicting and potentially enhancing the functional capacity of forest ecosystems in the Loess Plateau.
{"title":"Longitudinal distributions of CO2-fixing bacteria in forest soils and their potential associations with soil multifunctionality","authors":"Ying Wang , Yimei Huang , Na Li , Qian Huang , Baorong Wang , Shaoshan An","doi":"10.1016/j.ejsobi.2024.103689","DOIUrl":"10.1016/j.ejsobi.2024.103689","url":null,"abstract":"<div><div>Autotrophic microorganisms can fix carbon dioxide (CO<sub>2</sub>) into organic carbon (C), potentially offering a natural mechanism to mitigate global climate change. Forest soils, recognized as vast and critical C repositories with significant microbial CO<sub>2</sub> fixation rates, remain understudied, particularly regarding the spatial variations of autotrophic bacteria and their relationship to soil functions in arid regions. In this study, we systematically investigated soil multifunctionality, along with the spatial distribution of autotrophic bacterial communities identified by the RubisCO <em>cbbL</em> and <em>cbbM</em> genes, and the driving factors across a longitudinal gradient in the Loess Plateau forest soils. The investigation spanned an ∼850 km west-east transect with precipitation below 600 mm. The alpha diversity of <em>cbbL</em>-containing bacteria, as measured by the Chao1 index, was correlated with climatic variables such as precipitation and elevation instead of local soil characteristics. In contrast, the alpha diversity of <em>cbbM</em>-containing bacteria was associated with soil properties. The community composition of autotrophic bacteria, based on <em>cbbL</em> and <em>cbbM</em> genes, showed greater similarity in soils from the eastern Loess Plateau and was distinct from those in the western region. The <em>cbbL-</em> and <em>cbbM-</em>containing generalist taxa were subject to differential selection and promotion between the eastern and western regions. Temperature, soil pH and spatial variables were key drivers influencing the community composition of <em>cbbL-</em> and <em>cbbM-</em>containing bacteria. The diversity and communities of soil autotrophic bacteria significantly affected soil multifunctionality. The study demonstrates that soil autotrophic bacteria in forest soils are intricately connected to climatic conditions, soil pH and spatial factors, significantly impacting soil multifunctionality. These insights provide evidence that can be instrumental in predicting and potentially enhancing the functional capacity of forest ecosystems in the Loess Plateau.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103689"},"PeriodicalIF":3.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-22DOI: 10.1016/j.ejsobi.2024.103687
L. Vang Sørensen , S. Rodríguez-Martínez , M. Rollo , J. Klaminder
Ants serve as ecosystem engineers that maintain important ecological processes within forests. Given their ecological importance, it is a clear scientific shortcoming that we lack non-invasive methods to survey their behaviour inside common opaque habitats such as mounds, litter, and soil. In this study, we assess if acoustic signals from red wood ant (Formica rufa) mounds are useful to infer temporal changes in ant activity within forested ecosystems. We found that acoustic indices used previously as a proxy for soil fauna in soil ecological studies (Acoustic Complexity Index, Bioacoustic Index) can indeed separate sounds generated by the ant's daily routines (biophony) from other forest sounds. Yet, we also show that these indices are problematic proxies for soil diversity as they increase not only due to an increased number of species but also due to an increased number of the same species. Acoustic measures that incorporated the strength of acoustic signals, Average Power Density (APD) and Peak Power Density (PPD) also increased with increasing ant abundance and constituted the conceptually best proxy for ant activity. For example, the PPD could i) track diurnal changes in Formica rufa activity with a high temporal resolution (minutes) and ii) detect altered behavioural responses to temperature changes. We conclude that microphones detecting biophony can provide high-resolution information about in situ ant behaviours in forested ecosystems. Thus, passive acoustics monitoring offers a promising avenue as a non-invasive monitoring tool for soil macrofauna studies.
蚂蚁是维持森林重要生态过程的生态系统工程师。鉴于蚂蚁在生态方面的重要性，我们缺乏非侵入式方法来调查蚂蚁在土丘、垃圾和土壤等常见不透明栖息地内的行为，这是一个明显的科学缺陷。在这项研究中，我们评估了来自红木蚁（Formica rufa）蚁丘的声学信号是否有助于推断森林生态系统中蚂蚁活动的时间变化。我们发现，以前在土壤生态研究中用作土壤动物群替代物的声学指数（声学复杂性指数、生物声学指数）确实可以将蚂蚁日常活动产生的声音（生物声音）与其他森林声音区分开来。然而，我们也发现，这些指数是有问题的土壤多样性代用指标，因为它们的增加不仅是由于物种数量的增加，也是由于相同物种数量的增加。声学指标包括声信号强度、平均功率密度（Average Power Density，APD）和峰值功率密度（Peak Power Density，PPD），它们也随着蚂蚁数量的增加而增加，在概念上是蚂蚁活动的最佳代表。例如，PPD 可以 i) 以较高的时间分辨率（分钟）跟踪 Formica rufa 活动的昼夜变化；ii) 检测对温度变化的行为反应变化。我们的结论是，探测生物声音的麦克风可以提供有关森林生态系统中蚂蚁现场行为的高分辨率信息。因此，被动声学监测作为一种非侵入式监测工具，为土壤大型底栖动物研究提供了一条前景广阔的途径。
{"title":"Continuous measurement of red wood ant (Formica rufa) outdoor behaviour using passive acoustic monitoring","authors":"L. Vang Sørensen , S. Rodríguez-Martínez , M. Rollo , J. Klaminder","doi":"10.1016/j.ejsobi.2024.103687","DOIUrl":"10.1016/j.ejsobi.2024.103687","url":null,"abstract":"<div><div>Ants serve as ecosystem engineers that maintain important ecological processes within forests. Given their ecological importance, it is a clear scientific shortcoming that we lack non-invasive methods to survey their behaviour inside common opaque habitats such as mounds, litter, and soil. In this study, we assess if acoustic signals from red wood ant (<em>Formica rufa</em>) mounds are useful to infer temporal changes in ant activity within forested ecosystems. We found that acoustic indices used previously as a proxy for soil fauna in soil ecological studies (Acoustic Complexity Index, Bioacoustic Index) can indeed separate sounds generated by the ant's daily routines (biophony) from other forest sounds. Yet, we also show that these indices are problematic proxies for soil diversity as they increase not only due to an increased number of species but also due to an increased number of the same species. Acoustic measures that incorporated the strength of acoustic signals, Average Power Density (APD) and Peak Power Density (PPD) also increased with increasing ant abundance and constituted the conceptually best proxy for ant activity. For example, the PPD could i) track diurnal changes in <em>Formica rufa</em> activity with a high temporal resolution (minutes) and ii) detect altered behavioural responses to temperature changes. We conclude that microphones detecting biophony can provide high-resolution information about <em>in situ</em> ant behaviours in forested ecosystems. Thus, passive acoustics monitoring offers a promising avenue as a non-invasive monitoring tool for soil macrofauna studies.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103687"},"PeriodicalIF":3.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soil health is an emerging concern in agriculture and is dependent on the microbial communities in the rhizosphere (rhizobiome). Phosphite-based products are used as bio-stimulants and/or fungicides. However, there is a lack of studies evaluating the impact of these products in nurseries, especially at the level of the rhizobiome. This work aims to assess the impact of phosphite (Phi) application on the rhizobiome of Pinus radiata seedlings. Two application modes (foliar and irrigation) were compared in an experimental setup with control treatments. Gas exchange parameters were evaluated to assess plant physiological performance. Bacterial rhizobiome analysis was performed using next generation sequencing targeting the 16S rRNA gene. Results showed that Phi application did not significantly affect plant photosynthetic performance. However, Phi irrigation led to a significant decrease in rhizobiome richness and diversity compared to control. Beta diversity analysis confirmed distinct microbial communities in the irrigated group. At the genus level, several acidophilic taxa, including Burkholderia and Aciditerrimonas, were significantly enriched in phosphite-irrigated samples, while others like Mucilaginibacter were reduced. The study reveals that Phi application, especially through irrigation, alters the structure of the rhizobiome in pine seedlings, leading to a decrease in richness and bacterial diversity. These findings highlight the importance of understanding the effects of commercial products, such as phosphite. This understanding is crucial to ensure sustainable plant growth and maintain soil health.
{"title":"Pinus radiata seedlings rhizobiome shifts in response to foliar and root phosphite application","authors":"Frederico Leitão , Glória Pinto , Isabel Henriques","doi":"10.1016/j.ejsobi.2024.103688","DOIUrl":"10.1016/j.ejsobi.2024.103688","url":null,"abstract":"<div><div>Soil health is an emerging concern in agriculture and is dependent on the microbial communities in the rhizosphere (rhizobiome). Phosphite-based products are used as bio-stimulants and/or fungicides. However, there is a lack of studies evaluating the impact of these products in nurseries, especially at the level of the rhizobiome. This work aims to assess the impact of phosphite (Phi) application on the rhizobiome of <em>Pinus radiata</em> seedlings. Two application modes (foliar and irrigation) were compared in an experimental setup with control treatments. Gas exchange parameters were evaluated to assess plant physiological performance. Bacterial rhizobiome analysis was performed using next generation sequencing targeting the 16S rRNA gene. Results showed that Phi application did not significantly affect plant photosynthetic performance. However, Phi irrigation led to a significant decrease in rhizobiome richness and diversity compared to control. Beta diversity analysis confirmed distinct microbial communities in the irrigated group. At the genus level, several acidophilic taxa, including <em>Burkholderia</em> and <em>Aciditerrimonas</em>, were significantly enriched in phosphite-irrigated samples, while others like <em>Mucilaginibacter</em> were reduced. The study reveals that Phi application, especially through irrigation, alters the structure of the rhizobiome in pine seedlings, leading to a decrease in richness and bacterial diversity. These findings highlight the importance of understanding the effects of commercial products, such as phosphite. This understanding is crucial to ensure sustainable plant growth and maintain soil health.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103688"},"PeriodicalIF":3.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-16DOI: 10.1016/j.ejsobi.2024.103686
Xiaoping Wang , Yinshan Ma , Shiting Zhang
The effects of litter quality on soil microbial communities and enzyme activities have been widely documented; however, the specific relationship between soil enzyme activity, stoichiometry and their interactions with litter and soil properties across varying litter qualities remain unclear. Freshly fallen leaves of six species were collected and divided into low- and high-quality litter based on decomposition rates. We assessed the activities of carbon (C)-, nitrogen (N)- and phosphorus (P)-acquiring enzymes—β-1,-4-glucosidase (BG), β-1,4-N-acetylglucosaminidase (NAG), leucine aminopeptidase (LAP), and acid phosphatase (AP)—along with biotic and abiotic factors affecting enzyme activities (dissolved organic matter and microbial biomass in litter and soil) at five time points over 673 d. Enzyme vector analysis showed that vector lengths (microbial C limitation) were the largest across all treatments after 309 d, and all vector angles were > 45°, suggesting that soil microbes were more limited by P than by N during decomposition process. Redundancy analysis (RDA) and structural equation modeling (SEM) demonstrated that soil enzyme activity and stoichiometry were driven by different variables, depending on litter quality. In the control, soil dissolved organic carbon (SDOC) and phosphorus (SDOP) were the primary predictors of soil enzyme activity, while under low-quality litter addition, litter dissolved organic carbon (LDOC) and soil dissolved organic nitrogen (SDON) were the most influential factors, and under high-quality litter addition, litter microbial biomass carbon (LMBC), SDOC, and SDON were key drivers. Furthermore, SDOC was significantly and negatively correlated with vector length, explaining the greatest variation in soil enzyme stoichiometry across all treatments. Vector length and angle were better explained by LDOC and litter microbial biomass phosphorus (LMBP) under low-quality litter addition, in contrast, by litter microbial biomass nitrogen (LMBN) and litter dissolved organic nitrogen (LDON) under high-quality litter addition. Our results highlight that litter quality modulates soil microbial metabolism by influencing dissolved organic matter and microbial biomass in both litter and soil layers. This study reveals the mechanism mediating soil microbial metabolism during litter decomposition, which is crucial for understanding C and nutrient cycling in alpine grassland ecosystems.
枯落物质量对土壤微生物群落和酶活性的影响已被广泛记录；然而，不同质量的枯落物中土壤酶活性、化学计量及其与枯落物和土壤性质之间相互作用的具体关系仍不清楚。我们收集了六个物种的新鲜落叶，并根据分解率将其分为低质和优质枯落物。我们评估了碳（C）、氮（N）和磷（P）获取酶--β-1,-4-葡萄糖苷酶（BG）、β-1,4-N-乙酰葡萄糖苷酶（NAG）、亮氨酸氨肽酶（LAP）和酸性磷酸酶（AP）的活性、和酸性磷酸酶（AP），以及影响酶活性的生物和非生物因素（废弃物和土壤中的溶解有机物和微生物生物量）。酶矢量分析表明，309 d 后，矢量长度（微生物 C 限制）在所有处理中最大，且所有矢量角度均为 45°，表明在分解过程中，土壤微生物受 P 的限制大于受 N 的限制。冗余分析（RDA）和结构方程模型（SEM）表明，土壤酶活性和化学计量受不同变量的驱动，这取决于枯落物的质量。在对照组中，土壤溶解有机碳（SDOC）和磷（SDOP）是土壤酶活性的主要预测因子；在低质量垃圾添加情况下，垃圾溶解有机碳（LDOC）和土壤溶解有机氮（SDON）是最具影响力的因素；在高质量垃圾添加情况下，垃圾微生物生物量碳（LMBC）、SDOC和SDON是关键驱动因素。此外，SDOC 与矢量长度呈显著负相关，可解释所有处理中土壤酶化学计量的最大差异。在添加低质量枯落物的情况下，LDOC 和枯落物微生物生物量磷（LMBP）能更好地解释矢量长度和角度；相比之下，在添加高质量枯落物的情况下，枯落物微生物生物量氮（LMBN）和枯落物溶解有机氮（LDON）能更好地解释矢量长度和角度。我们的研究结果突出表明，垃圾质量通过影响垃圾层和土壤层中的溶解有机物和微生物生物量来调节土壤微生物代谢。这项研究揭示了枯落物分解过程中土壤微生物新陈代谢的调节机制，这对了解高寒草地生态系统的碳和养分循环至关重要。
{"title":"Soil enzyme activity and stoichiometry indicates that litter quality regulates soil microbial nutrient demand in a Tibetan alpine meadow","authors":"Xiaoping Wang , Yinshan Ma , Shiting Zhang","doi":"10.1016/j.ejsobi.2024.103686","DOIUrl":"10.1016/j.ejsobi.2024.103686","url":null,"abstract":"<div><div>The effects of litter quality on soil microbial communities and enzyme activities have been widely documented; however, the specific relationship between soil enzyme activity, stoichiometry and their interactions with litter and soil properties across varying litter qualities remain unclear. Freshly fallen leaves of six species were collected and divided into low- and high-quality litter based on decomposition rates. We assessed the activities of carbon (C)-, nitrogen (N)- and phosphorus (P)-acquiring enzymes—β-1,-4-glucosidase (BG), β-1,4-N-acetylglucosaminidase (NAG), leucine aminopeptidase (LAP), and acid phosphatase (AP)—along with biotic and abiotic factors affecting enzyme activities (dissolved organic matter and microbial biomass in litter and soil) at five time points over 673 d. Enzyme vector analysis showed that vector lengths (microbial C limitation) were the largest across all treatments after 309 d, and all vector angles were > 45°, suggesting that soil microbes were more limited by P than by N during decomposition process. Redundancy analysis (RDA) and structural equation modeling (SEM) demonstrated that soil enzyme activity and stoichiometry were driven by different variables, depending on litter quality. In the control, soil dissolved organic carbon (SDOC) and phosphorus (SDOP) were the primary predictors of soil enzyme activity, while under low-quality litter addition, litter dissolved organic carbon (LDOC) and soil dissolved organic nitrogen (SDON) were the most influential factors, and under high-quality litter addition, litter microbial biomass carbon (LMBC), SDOC, and SDON were key drivers. Furthermore, SDOC was significantly and negatively correlated with vector length, explaining the greatest variation in soil enzyme stoichiometry across all treatments. Vector length and angle were better explained by LDOC and litter microbial biomass phosphorus (LMBP) under low-quality litter addition, in contrast, by litter microbial biomass nitrogen (LMBN) and litter dissolved organic nitrogen (LDON) under high-quality litter addition. Our results highlight that litter quality modulates soil microbial metabolism by influencing dissolved organic matter and microbial biomass in both litter and soil layers. This study reveals the mechanism mediating soil microbial metabolism during litter decomposition, which is crucial for understanding C and nutrient cycling in alpine grassland ecosystems.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103686"},"PeriodicalIF":3.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fusarium wilt is a severe soil-borne disease that affects faba bean production. Faba bean-wheat intercropping is often used to control the occurrence of Fusarium wilt in faba bean.
Aims
To evaluate the effects of faba bean-wheat intercropping on the occurrence of faba bean Fusarium wilt and soil microecology.
Methods
We established two planting patterns, faba bean monocropping (M) and faba bean-wheat intercropping (I), to investigate Fusarium wilt occurrence and plant dry weight and assess changes in soil enzyme activities, microbial diversity, and community composition during different stages of disease onset.
Results
Intercropping effectively controlled faba bean Fusarium wilt at the three disease stages and increased the dry weight of faba bean plants. Intercropping promoted the activities of catalase (CAT), urease, sucrase, and acid phosphatase in the rhizosphere soil of faba bean at three disease stages. Bacterial and fungal diversity decreased with disease progression, and intercropping mitigated this trend. Compared with monocropping, intercropping increased the abundance of beneficial bacteria such as Proteobacteria, Actinobacteriota, Gemmatimonadota, Gemmatimonas, Conexibacter, and Sphingomonas, while reducing the abundance of pathogenic fungi such as Alternaria, Cladosporium, and Fusarium. Intercropping also increased the abundance of arbuscular mycorrhiza, soil saprophytes, and undefined saprophytes while decreasing the abundance of plant pathogens.
Conclusion
Faba bean-wheat intercropping enhanced soil enzyme activities, effective nutrient content, and alpha diversity indices of bacteria and fungi in the rhizosphere soil of faba bean, while promoting the abundance of beneficial bacteria, arbuscular mycorrhizal fungi, as well as both soil and undefined humus. Simultaneously, intercropping reduced the abundance of plant pathogens, facilitated nutrient cycling in the soil, provided sufficient nutrients for crop uptake, and mitigated the toxic effects of hydrogen peroxide on cells. Ultimately, this resulted in a reduced occurrence of Fusarium wilt.
{"title":"Faba bean-wheat intercropping controls the occurrence of faba bean Fusarium wilt by improving the microecological environment of rhizosphere soil","authors":"Yiran Zheng , Jing Zhang , Dongsheng Wang, Siyin Yang, Zixuan Cen, Yan Dong","doi":"10.1016/j.ejsobi.2024.103685","DOIUrl":"10.1016/j.ejsobi.2024.103685","url":null,"abstract":"<div><h3>Background</h3><div>Fusarium wilt is a severe soil-borne disease that affects faba bean production. Faba bean-wheat intercropping is often used to control the occurrence of Fusarium wilt in faba bean.</div></div><div><h3>Aims</h3><div>To evaluate the effects of faba bean-wheat intercropping on the occurrence of faba bean Fusarium wilt and soil microecology.</div></div><div><h3>Methods</h3><div>We established two planting patterns, faba bean monocropping (M) and faba bean-wheat intercropping (I), to investigate Fusarium wilt occurrence and plant dry weight and assess changes in soil enzyme activities, microbial diversity, and community composition during different stages of disease onset.</div></div><div><h3>Results</h3><div>Intercropping effectively controlled faba bean Fusarium wilt at the three disease stages and increased the dry weight of faba bean plants. Intercropping promoted the activities of catalase (CAT), urease, sucrase, and acid phosphatase in the rhizosphere soil of faba bean at three disease stages. Bacterial and fungal diversity decreased with disease progression, and intercropping mitigated this trend. Compared with monocropping, intercropping increased the abundance of beneficial bacteria such as Proteobacteria, Actinobacteriota, Gemmatimonadota, <em>Gemmatimonas</em>, <em>Conexibacter</em>, and <em>Sphingomonas</em>, while reducing the abundance of pathogenic fungi such as <em>Alternaria</em>, <em>Cladosporium</em>, and <em>Fusarium</em>. Intercropping also increased the abundance of arbuscular mycorrhiza, soil saprophytes, and undefined saprophytes while decreasing the abundance of plant pathogens.</div></div><div><h3>Conclusion</h3><div>Faba bean-wheat intercropping enhanced soil enzyme activities, effective nutrient content, and alpha diversity indices of bacteria and fungi in the rhizosphere soil of faba bean, while promoting the abundance of beneficial bacteria, arbuscular mycorrhizal fungi, as well as both soil and undefined humus. Simultaneously, intercropping reduced the abundance of plant pathogens, facilitated nutrient cycling in the soil, provided sufficient nutrients for crop uptake, and mitigated the toxic effects of hydrogen peroxide on cells. Ultimately, this resulted in a reduced occurrence of Fusarium wilt.</div></div>","PeriodicalId":12057,"journal":{"name":"European Journal of Soil Biology","volume":"123 ","pages":"Article 103685"},"PeriodicalIF":3.7,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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