{"title":"Nonlinear response of soil nitric oxide emissions to fertilizer nitrogen across croplands","authors":"","doi":"10.1007/s00374-024-01818-9","DOIUrl":"https://doi.org/10.1007/s00374-024-01818-9","url":null,"abstract":"<h3>Abstract</h3> <p>Nitric oxide (NO), as a short-lived climate forcer, has direct and indirect detrimental impacts on environmental quality and human health. The amount of nitrogen (N) fertilizer application to agricultural soils is considered a robust predictor of total NO emissions, but the estimates of cropland NO emissions have large uncertainties due to the widely used constant emission factors (EF) as e.g., default values recommended by Intergovernmental Panel on Climate Change (IPCC) methodologies. By compiling 223 field experiments with at least three N-input levels across various croplands, we performed a meta-analysis to determine how soil NO emissions respond to N inputs. Our results showed for the first time that the mean change in EF per unit of additional N input (∆EF) across all available data was significantly higher as compared to zero, indicating that the NO response to N additions increased significantly faster than the assumed linear. On average, upland grain crops showed significantly higher ∆EF than that of horticultural crops or lowland rice. A higher ∆EF was also appeared in sites with mean annual precipitation < 600 mm, mean annual temperature ≥ 15 °C, soil organic carbon ≥ 14 g C kg<sup>− 1</sup> or total <em>N</em> ≥ 1.4 g N kg<sup>− 1</sup>, and where synthetic N fertilizers were usually applied. By assuming various N application rates, the IPCC default (0.7% or 1.1%) EF model would have overestimated or underestimated NO emissions compared to our ∆EF model. Overall, our meta-analysis results exert high potential to improve estimates of cropland NO inventories, and help address disparities in global NO budgets and develop more targeted mitigation efforts.</p>","PeriodicalId":9210,"journal":{"name":"Biology and Fertility of Soils","volume":"131 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140196091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Canonical ammonia oxidizers and comammox Clade A play active roles in nitrification in a black soil at different pH and ammonium concentrations","authors":"Xin Bai, Xiaojing Hu, Junjie Liu, Zhenhua Yu, Jian Jin, Xiaobing Liu, Guanghua Wang","doi":"10.1007/s00374-024-01812-1","DOIUrl":"https://doi.org/10.1007/s00374-024-01812-1","url":null,"abstract":"<p>The discovery of complete ammonia oxidizers (comammox) challenged our cognition of the nitrification process. Ammonia oxidizing archaea (AOA), ammonia oxidizing bacteria (AOB) and comammox can carry out soil autotrophic nitrification process together. However, the differentiation of the ecological niche of three types of ammonia oxidizers in different environments has not been fully discovered. In this study, a typical black soil collected from northeast China was adjusted to different pH (original and adjusted pH were 4.29 and 7, respectively) and NH<sub>4</sub><sup>+</sup>-N concentrations (weekly adding and without adding 100 mg NH<sub>4</sub><sup>+</sup>-N kg<sup>− 1</sup> soil). The activities of AOA, AOB and comammox were examined using DNA stable isotope probing approach with <sup>13</sup>CO<sub>2</sub>, the phylogenetic information of active ammonia oxidizers was detected by high-throughput sequencing. The results showed that niche differentiation of AOA, AOB and comammox in black soils differed with soil pH. AOA dominated the nitrification process in acidic soils, while AOA, AOB and comammox Clade A taken part in the nitrification process in neutral soils. Among them, AOB showed strong activity in the soils with the high N treatment. The active AOA mainly belonged to <i>Nitrososphaera</i> in acidic and neutral soils. The active AOB and comammox Clade A mainly belonged to <i>Nitrosospira</i> and Clade A.2 in neutral soils, respectively. Taken together, the results highlighted the significance of canonical ammonia oxidizers in nitrification process of black soils, and comammox Clade A played an active role in neutral condition.</p>","PeriodicalId":9210,"journal":{"name":"Biology and Fertility of Soils","volume":"2015 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140188756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rainer Georg Joergensen, Michael Hemkemeyer, Lukas Beule, Janyl Iskakova, Zhyldyz Oskonbaeva, Pauline Sophie Rummel, Sanja Annabell Schwalb, Florian Wichern
{"title":"A hitchhiker’s guide: estimates of microbial biomass and microbial gene abundance in soil","authors":"Rainer Georg Joergensen, Michael Hemkemeyer, Lukas Beule, Janyl Iskakova, Zhyldyz Oskonbaeva, Pauline Sophie Rummel, Sanja Annabell Schwalb, Florian Wichern","doi":"10.1007/s00374-024-01810-3","DOIUrl":"https://doi.org/10.1007/s00374-024-01810-3","url":null,"abstract":"<p>Information on microbial biomass carbon (MBC) is crucial to assess their stocks and role for plant nutrient release in soil. Next to fumigation-extraction, molecular methods are routinely used to estimate the contribution of fungi, bacteria, and archaea to the soil microbial community. However, more information on the links between these different indices would deepen the understanding of microbial processes. The current study is based on 11 datasets, which contain MBC and MBN data obtained by fumigation-extraction and information on bacterial, archaeal, and fungal gene abundance, totalling 765 data points from agricultural, forest, and rangeland soils. Some of these datasets additionally provide information on double-stranded deoxyribonucleic acid (dsDNA) and fungal ergosterol. MBC varied around the median of 206 µg g<sup>−1</sup> soil. MBN followed with a median MB-C/N ratio of 4.1. Median microbial gene abundance declined from bacteria (96 × 10<sup>8</sup>) to archaea (4.4 × 10<sup>8</sup>) to fungi (1.8 × 10<sup>8</sup>). The median ratio of MBC/dsDNA was 15.8 and that of bacteria/dsDNA was 5.8 × 10<sup>8</sup> µg<sup>−1</sup>. The relationships between MBC and dsDNA as well as between bacterial gene abundance and dsDNA were both negatively affected by soil pH and positively by clay content. The median ergosterol/MBC and fungi/ergosterol ratios were 0.20% and 4.7 (n × 10<sup>8</sup> µg<sup>−1</sup>), respectively. The relationship between fungal gene abundance and ergosterol was negatively affected by soil pH and clay content. Our study suggests that combining fumigation-extraction with molecular tools allows more precise insights on the physiological interactions of soil microorganisms with their surrounding environment.</p>","PeriodicalId":9210,"journal":{"name":"Biology and Fertility of Soils","volume":"105 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140161960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ziyu Yang, Qirui Zhu, Yuping Zhang, Pan Jiang, Yizhe Wang, Jiangchi Fei, Xiangmin Rong, Jianwei Peng, Xiaomeng Wei, Gongwen Luo
{"title":"Soil carbon storage and accessibility drive microbial carbon use efficiency by regulating microbial diversity and key taxa in intercropping ecosystems","authors":"Ziyu Yang, Qirui Zhu, Yuping Zhang, Pan Jiang, Yizhe Wang, Jiangchi Fei, Xiangmin Rong, Jianwei Peng, Xiaomeng Wei, Gongwen Luo","doi":"10.1007/s00374-024-01804-1","DOIUrl":"https://doi.org/10.1007/s00374-024-01804-1","url":null,"abstract":"<p>Intercropping is a powerful practice to alter the allocation of photosynthetic carbon (C) to belowground ecosystems via promotion of diversified plant communities. The feedback of soil C stability to intercropping is controlled by microbial C use efficiency (CUE). Despite its significance, there is currently insufficient evidence to decipher how soil microbial CUE reacts to intercropping. By combining a 10-year-long intercropping experiment with a substrate-independent <sup>18</sup>O-H<sub>2</sub>O labelling approach and high-throughput sequencing, we elucidated the performance of intercropping on soil C pool and microbial metabolic traits as well as their relationships with soil microbial communities. Compared with monoculture, maize intercropping with peanut and soybean significantly increased soil C storage, soil mineral-associated organic C (MAOC), soil dissolved organic (DOC), and soil microbial biomass (MBC) contents at maize four growth stages. Soil microbial CUE increased significantly, especially at maize flowering and mature stages, as a consequence of enhanced microbial growth and biomass turnover rate after maize intercropping with peanut and soybean. Soil C storage and accessibility indicators (e.g., MAOC, DOC, and MBC contents) could significantly predict the changes of soil microbial diversity and core taxa. Meanwhile, the beta-diversity (community composition) of soil bacteria, fungi, saprotroph and protists, as well as rare fungal taxa were positively correlated with soil microbial CUE, and these indicators showed a high prediction of the microbial CUE. Soil C storage and accessibility indicators directly and indirectly influenced soil microbial CUE by regulating microbial diversity and key taxa. Soil microbial diversity and core taxa directly and indirectly influenced microbial CUE by mediating microbial respiration, growth, biomass, and enzyme activity, which mediated by soil C storage and accessibility. These findings provide an evidence for the associations between microbial diversity, CUE, and soil C stability, highlighting the importance of intercropping-driven soil microbiome to enhance soil microbial CUE.</p>","PeriodicalId":9210,"journal":{"name":"Biology and Fertility of Soils","volume":"25 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140139415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High soil moisture rather than drying-rewetting cycles reduces the effectiveness of nitrification inhibitors in mitigating N2O emissions","authors":"","doi":"10.1007/s00374-024-01811-2","DOIUrl":"https://doi.org/10.1007/s00374-024-01811-2","url":null,"abstract":"<h3>Abstract</h3> <p>Climate change has been intensifying soil drying and rewetting cycles, which can alter the soil microbiome structure and activity. Here we hypothesized that a soil drying-rewetting cycle enhances biodegradation and, hence, decreases the effectiveness of nitrification inhibitors (NIs). The effectiveness of DMPP (3,4-Dimethylpyrazole phosphate) and MP + TZ (3-Methylpyrazol and Triazol) was evaluated in 60-day incubation studies under a drying and rewetting cycle relative to constant low and high soil moisture conditions (40% and 80% water-holding capacity, WHC, respectively) in two different textured soils. The measurements included (i) daily and cumulative N<sub>2</sub>O-N emissions, (ii) soil NH<sub>4</sub><sup>+</sup>-N and NO<sub>3</sub><sup>−</sup>-N concentrations, and (iii) the composition of bacterial soil communities. Application of DMPP and MP + TZ reduced the overall N<sub>2</sub>O-N emissions under drying-rewetting (-45%), as well as under 40% WHC (-39%) and 80% WHC (-25%). DMPP retarded nitrification and decreased N<sub>2</sub>O-N release from the sandy and silt loam soils, while MP + TZ mitigated N<sub>2</sub>O-N production only from the silt loam soil. Unexpectedly, between days 30 and 60, N<sub>2</sub>O-N emissions from NI-treated soils increased by up to fivefold relative to the No-NI treatment in the silt loam soil at 80% WHC. Likewise, the relative abundance of the studied nitrifying bacteria indicated that the NIs had only short-term effectiveness in the silt loam soil. These results suggested that DMPP and MP + TZ might trigger high N<sub>2</sub>O-N release from fine-textured soil with constant high moisture after this short-term inhibitory effect. In conclusion, DMPP and MP + TZ effectively reduce N<sub>2</sub>O-N emissions under soil drying and rewetting.</p>","PeriodicalId":9210,"journal":{"name":"Biology and Fertility of Soils","volume":"84 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140139393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aline do Amaral Leite, Arnon Afonso de Souza Cardoso, Rafael de Almeida Leite, Ana Maria Villarreal Barrera, Daniela Dourado Leal Queiroz, Thiago Costa Viana, Silvia Maria de Oliveira-Longatti, Carlos Alberto Silva, Fatima Maria de Souza Moreira, Johannes Lehmann, Leônidas Carrijo Azevedo Melo
{"title":"Phosphate-solubilizing bacteria increase maize phosphorus uptake from magnesium-enriched poultry manure biochar","authors":"Aline do Amaral Leite, Arnon Afonso de Souza Cardoso, Rafael de Almeida Leite, Ana Maria Villarreal Barrera, Daniela Dourado Leal Queiroz, Thiago Costa Viana, Silvia Maria de Oliveira-Longatti, Carlos Alberto Silva, Fatima Maria de Souza Moreira, Johannes Lehmann, Leônidas Carrijo Azevedo Melo","doi":"10.1007/s00374-024-01808-x","DOIUrl":"https://doi.org/10.1007/s00374-024-01808-x","url":null,"abstract":"<p>Manure-derived biochars have a fertilizer potential as pyrolysis concentrates non-volatile nutrients. The addition of magnesium (Mg) to poultry manure enhances its Mg/Ca ratio and could increase soluble P by phosphate-solubilizing bacteria (PSB). Our objective was to assess the potential of PSB strains to solubilize P from both unenriched and Mg-enriched biochar and to evaluate the growth of maize in an Oxisol fertilized with biochar (100 mg kg<sup>−1</sup> total P) to satisfy plant P needs. We examined the strains: <i>Paraburkholderia fungorum</i> UFLA 04–155, <i>Pseudomonas anuradhapurensis</i> UFPI B5-8A, <i>Paenibacillus chondroitinus</i> UFLA 03–116, <i>Acinetobacter pittii</i> UFLA 03–09, and <i>Rhizobium tropici</i> CIAT 899. Biochar was made from poultry manure at temperatures of 350 °C, 500 °C, and 650 °C. Maize growth and P uptake were assessed in plants after 15 and 30 days under greenhouse conditions. The strain <i>P. anuradhapurensis</i> UFPI B5-8A significantly released more P from Mg-biochar (82% of the total P added) than from the unenriched biochar (74% of the total P added). Furthermore, this strain released tartaric and gluconic acids when mixed with the Mg-biochar, whereas malic acid was primarily exuded when applied to unenriched biochar. Similarly, <i>P. anuradhapurensis</i> UFPI B5-8A inoculation or Mg enrichment resulted in a 20% increase in P uptake by maize compared to unenriched biochar. Therefore, a synergistic approach using Mg-biochar and inoculation with PSB increases phosphate availability from poultry manure and maize P use efficiency.</p>","PeriodicalId":9210,"journal":{"name":"Biology and Fertility of Soils","volume":"2016 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140114395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Irina Yankelzon, Georg Willibald, Michael Dannenmann, Francois Malique, Ulrike Ostler, Clemens Scheer, Klaus Butterbach-Bahl
{"title":"A new incubation system to simultaneously measure n2 as well as n2o and co2 fluxes from plant-soil mesocosms","authors":"Irina Yankelzon, Georg Willibald, Michael Dannenmann, Francois Malique, Ulrike Ostler, Clemens Scheer, Klaus Butterbach-Bahl","doi":"10.1007/s00374-024-01809-w","DOIUrl":"https://doi.org/10.1007/s00374-024-01809-w","url":null,"abstract":"<p>This study presents a novel plant-soil mesocosm system designed for cultivating plants over periods ranging from days to weeks while continuously measuring fluxes of N<sub>2</sub>, N<sub>2</sub>O and CO<sub>2</sub>. For proof of concept, we conducted a 33-day incubation experiment using six soil mesocosms, with three containing germinated wheat plants and three left plant-free. To validate the magnitude of N<sub>2</sub> and N<sub>2</sub>O fluxes, we used <sup>15</sup>N-enriched fertilizer and a <sup>15</sup>N mass balance approach. The system inherent leakage rate was about 55 µg N m<sup>− 2</sup> h<sup>− 1</sup> for N<sub>2</sub>, while N<sub>2</sub>O leakage rates were below the detection limit (< 1 µg N m<sup>− 2</sup> h<sup>− 1</sup>). In our experiment, we found higher cumulative gaseous N<sub>2</sub> + N<sub>2</sub>O losses in sown soil (0.34 ± 0.02 g N m<sup>− 2</sup>) as compared to bare soil (0.23 ± 0.01 g N m<sup>− 2</sup>). N<sub>2</sub> fluxes accounted for approximately 94–96% of total gaseous N losses in both planted and unplanted mesocosms. N losses, as determined by the <sup>15</sup>N mass balance approach, were found to be 1.7 ± 0.5 g N m<sup>− 2</sup> for the sown soil and 1.7 ± 0.6 g N m<sup>− 2</sup> for the bare soil, indicating an inconsistency between the two assessment methods. Soil respiration rates were also higher in sown mesocosms, with cumulative soil and aboveground biomass CO<sub>2</sub> respiration reaching 4.8 ± 0.1 and 4.0 ± 0.1 g C m<sup>− 2</sup> over the 33-day incubation period, in sown and bare soil, respectively. Overall, this study measured the effect of wheat growth on soil denitrification, highlighting the sensitivity and utility of this advanced incubation system for such studies.</p>","PeriodicalId":9210,"journal":{"name":"Biology and Fertility of Soils","volume":"66 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140123947","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H.-J. Vogel, W. Amelung, C. Baum, M. Bonkowski, S. Blagodatsky, R. Grosch, M. Herbst, R. Kiese, S. Koch, M. Kuhwald, S. König, P. Leinweber, B. Lennartz, C. W. Müller, H. Pagel, M. C. Rillig, J. Rüschhoff, D. Russell, A. Schnepf, S. Schulz, N. Siebers, D. Vetterlein, C. Wachendorf, U. Weller, U. Wollschläger
{"title":"How to adequately represent biological processes in modeling multifunctionality of arable soils","authors":"H.-J. Vogel, W. Amelung, C. Baum, M. Bonkowski, S. Blagodatsky, R. Grosch, M. Herbst, R. Kiese, S. Koch, M. Kuhwald, S. König, P. Leinweber, B. Lennartz, C. W. Müller, H. Pagel, M. C. Rillig, J. Rüschhoff, D. Russell, A. Schnepf, S. Schulz, N. Siebers, D. Vetterlein, C. Wachendorf, U. Weller, U. Wollschläger","doi":"10.1007/s00374-024-01802-3","DOIUrl":"https://doi.org/10.1007/s00374-024-01802-3","url":null,"abstract":"<p>Essential soil functions such as plant productivity, C storage, nutrient cycling and the storage and purification of water all depend on soil biological processes. Given this insight, it is remarkable that in modeling of these soil functions, the various biological actors usually do not play an explicit role. In this review and perspective paper we analyze the state of the art in modeling these soil functions and how biological processes could more adequately be accounted for. We do this for six different biologically driven processes clusters that are key for understanding soil functions, namely i) turnover of soil organic matter, ii) N cycling, iii) P dynamics, iv) biodegradation of contaminants v) plant disease control and vi) soil structure formation. A major conclusion is that the development of models to predict changes in soil functions at the scale of soil profiles (i.e. pedons) should be better rooted in the underlying biological processes that are known to a large extent. This is prerequisite to arrive at the predictive models that we urgently need under current conditions of Global Change.</p>","PeriodicalId":9210,"journal":{"name":"Biology and Fertility of Soils","volume":"19 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140096989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qing Qu, Lei Deng, Anna Gunina, Xuying Hai, Jun Deng, Zhouping Shangguan, Yakov Kuzyakov
{"title":"Grazing exclusion increases soil organic C through microbial necromass of root-derived C as traced by 13C labelling photosynthate","authors":"Qing Qu, Lei Deng, Anna Gunina, Xuying Hai, Jun Deng, Zhouping Shangguan, Yakov Kuzyakov","doi":"10.1007/s00374-024-01807-y","DOIUrl":"https://doi.org/10.1007/s00374-024-01807-y","url":null,"abstract":"<p>Grasslands store large amounts of C; however, the underlying mechanisms of soil C sequestration after grazing exclusion are not well known. This study aimed to elucidate the drivers of soil organic C (SOC) sequestration from plant and microbial residues in temperate grasslands after long-term (~ 40 years) grazing exclusion. We conducted in situ <sup>13</sup>C-CO<sub>2</sub> labelling experiments in the field and traced <sup>13</sup>C in plant-soil systems paired with biomarkers to assess the C input from plants into soils. Long-term grazing exclusion increased all plant and soil pools including shoots, roots, microbial biomass and necromass. <sup>13</sup>C allocation in these pools also increased, whereas <sup>13</sup>C was lost via respiration as CO<sub>2</sub> from soils decreased. <sup>13</sup>C incorporation into the soil and microbial biomass increased with <sup>13</sup>C allocation into the roots. Grazing exclusion for over 40 years increased the total SOC content by 190%, largely due to increases in fungal necromass C, and there was a minor contribution of lignin phenols to SOC accrual (0.8%). Consequently, grazing exclusion boosts not only aboveground biomass, but also larger roots and rhizodeposition, leading to microbial biomass and necromass formation. Microbial necromass and lignin phenols contribute to SOC accrual under grazing exclusion, and microbial necromass, especially fungal necromass, makes a larger contribution than lignin phenols.</p>","PeriodicalId":9210,"journal":{"name":"Biology and Fertility of Soils","volume":"7 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140032201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuhong Li, Mouliang Xiao, Liang Wei, Qiong Liu, Zhenke Zhu, Hongzhao Yuan, Jinshui Wu, Jun Yuan, Xiaohong Wu, Yakov Kuzyakov, Tida Ge
{"title":"Bacterial necromass determines the response of mineral-associated organic matter to elevated CO2","authors":"Yuhong Li, Mouliang Xiao, Liang Wei, Qiong Liu, Zhenke Zhu, Hongzhao Yuan, Jinshui Wu, Jun Yuan, Xiaohong Wu, Yakov Kuzyakov, Tida Ge","doi":"10.1007/s00374-024-01803-2","DOIUrl":"https://doi.org/10.1007/s00374-024-01803-2","url":null,"abstract":"<p>Microorganisms regulate soil organic matter (SOM) formation through accumulation and decomposition of microbial necromass, which is directly and indirectly affected by elevated CO<sub>2</sub> and N fertilization. We investigated the role of microorganisms in SOM formation by analyzing <sup>13</sup>C recovery in microorganisms and carbon pools in paddy soil under two CO<sub>2</sub> levels, with and without N fertilization, after continuous <sup>13</sup>CO<sub>2</sub> labelling was stopped. Microbial turnover transferred <sup>13</sup>C from living microbial biomass (determined by the decrease in phospholipid fatty acids) to necromass (determined by the increase in amino sugars). <sup>13</sup>C incorporation in fungal living biomass and necromass was higher than that in bacteria. Bacterial turnover was faster than necromass decomposition, resulting in net necromass accumulation over time; fungal necromass remained stable. Elevated CO<sub>2</sub> and N fertilization increased the net accumulation of bacterial, but not fungal, necromass. CO<sub>2</sub> levels, but not N fertilization, significantly affected <sup>13</sup>C incorporation in SOM pools. Elevated CO<sub>2</sub> increased <sup>13</sup>C in particulate organic matter via the roots, and in the mineral-associated organic matter (MAOM) via bacterial, but not fungal, necromass. Overall, bacterial necromass plays a dominant role in the MAOM formation response to elevated CO<sub>2</sub> because bacteria are sensitive to elevated CO<sub>2</sub>.</p>","PeriodicalId":9210,"journal":{"name":"Biology and Fertility of Soils","volume":"22 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140016580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}