Soil Biology & Biochemistry最新文献

{"title":"Comparison of different methods for estimating microbial biomass in biochar-amended soils","authors":"Sara Paliaga ,&nbsp;Vito Armando Laudicina ,&nbsp;Sofia Maria Muscarella ,&nbsp;Daniel Said-Pullicino ,&nbsp;Luigi Badalucco","doi":"10.1016/j.soilbio.2025.109733","DOIUrl":"10.1016/j.soilbio.2025.109733","url":null,"abstract":"<div><div>Biochar use as a soil amendment can improve soil functions, enhances microbial activity, and increases crop production. However, due to its high sorptive capacity, it may interfere with traditional methods for determining soil microbial biomass, specifically chloroform fumigation-incubation (FI) and fumigation-extraction (FE). This study aimed to assess the impact of biochar on microbial biomass determination using traditional methods and a new CO₂ high pressurization (CO2HP) technique. Five treatments were set up: unamended soil (control), and soil amended with two types of biochar, produced at 440 °C (B440) or 880 °C (B880), at two application rates (20 or 40 t ha⁻¹). Following cell lysis by fumigation or CO2HP, released microbial C (ΔC_mic) was estimated by determining microbial respiration over a 10-d incubation (FI and CO2HP-I methods, respectively) or by extracting soluble organic C (FE, and CO2HP-E, respectively), while released microbial N (ΔN_mic) was estimated by determining extractable total N exclusively by FE and CO2HP-E methods.</div><div>Without biochar, ΔC_mic estimates were similar across FE, FI, and CO2HP-E methods. Contrarily, CO2HP-I method greatly overestimated ΔC_mic compared to the other three methods, particularly at the higher biochar rate, suggesting that the adsorption of CO₂ within biochar pores during CO2HP treatment and subsequent slow release during incubation could have produced artifacts. The presence of B880 resulted in a decrease in ΔC_mic values, which might have been caused by an acclimation of microbial biomass to new habitat. Contrarily, the addition of B440, increased ΔC_mic when determined by the FE method, compared to FI and CO2HP-E methods. This suggested an overestimation of extractable C after fumigation, possibly due to adsorption of CHCl₃ by the B440 biochar, rich in functional groups, that might have bound CHCl₃. We concluded that biochar interfered with the determination of ΔC_micand ΔN_mic as a function of both type and amount added.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109733"},"PeriodicalIF":9.8,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143057005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental access to cellulose oxidation and the dynamics of microbial carbon and energy use in artificial soil under varying temperature, water content, and C/N ratio","authors":"Shiyue Yang ,&nbsp;Alina Rupp ,&nbsp;Matthias Kästner ,&nbsp;Hauke Harms ,&nbsp;Anja Miltner ,&nbsp;Thomas Maskow","doi":"10.1016/j.soilbio.2025.109717","DOIUrl":"10.1016/j.soilbio.2025.109717","url":null,"abstract":"<div><div>Soil is one of the most important natural carbon sinks, alongside its many other critical functions. The ratio of carbon incorporated into the soil system for instance as biomass as a proportion of carbon consumption from a given substrate is defined as carbon use efficiency (CUE). CUE is assumed to depend on environmental conditions. However, the conservation of energy within the soil system, quantified as energy use efficiency (EUE), has not yet been thoroughly studied related to CUE. To study the effects of environmental conditions on cellulose degradation in the absence of soil organic matter background, we utilized artificial soil to analyse their impact on CUE and EUE. We quantified CO₂ evolution rate, heat production rate, and cellulose degradation, at three water contents (10%, 14.4% and 19%), two C/N ratios (9 and 18), and two temperatures (7 <span><math><mrow><mo>°C</mo></mrow></math></span> and 20 <span><math><mrow><mo>°C</mo></mrow></math></span>). Environmental conditions significantly influenced the primary parameters such as CO₂ evolution, heat production, and cellulose degradation rate while the derived parameters CUE and in particular EUE were less sensitive. Among the studied factors, water content had the least influence on ultimate CUE and EUE. Conversely, decreases in nitrogen supply and temperature tended to increase CUE without significantly affecting EUE, which is generally higher than CUE. Over the degradation process, CUE often started from high values &gt; 90% and then decreased to lower ones around 50%, whereas the EUE remained more constant on a higher level. The variations of CUE and EUE suggest alterations in the stoichiometry of the microbial growth reaction and thus add additional factors (e.g. time lapse of the degradation process) to be considered for their assessment.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109717"},"PeriodicalIF":9.8,"publicationDate":"2025-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143044719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distinct seasonal and annual variability of prokaryotes, fungi and protists in cropland soil under different tillage systems and soil texture","authors":"Haotian Wang ,&nbsp;Jingjing Yang ,&nbsp;Damien R. Finn ,&nbsp;Joachim Brunotte ,&nbsp;Christoph C. Tebbe","doi":"10.1016/j.soilbio.2025.109732","DOIUrl":"10.1016/j.soilbio.2025.109732","url":null,"abstract":"<div><div>A sustainable use of croplands should utilize beneficial services provided by their resident soil microbiome. To identify potentially adverse environmental effects on soil microbiomes in the future, a better understanding of their natural variability is fundamental. Here, we characterized the abundance and diversity of soil microbial communities over 2 years at two-week intervals on three neighboring fields at an operational farm in Northern Germany. Field soils differed in texture (clay, loam) and tillage (soil conservation vs. conventional). PCR-amplicon analyses of soil DNA revealed distinct temporal variations of bacteria, archaea, fungi, and protists (Cercozoa and Endomyxa). Annual differences and seasonal effects on all microbial groups were detected. In addition to soil pH, prokaryotic communities varied with total soil C and N, but fungi with temperature and precipitation. The C/N ratio had contrasting effects on prokaryotic phyla and protistan classes, but all fungal phyla responded positively. Irrespective of the sampling date, prokaryotic and fungal but not protistan community compositions from the three soils were distinct. Compositional turnover rates were higher for fungi and protists than for prokaryotes and, for all, lower in clay. Conventional tillage had the strongest effect on protist diversity. In co-occurrence networks, most nodes were provided by prokaryotes, but highly connected nodes by predatory protists in the first, and by saprotrophic fungi in the second year. The temporal variation established here can provide insights of what is natural and thus below the limits of concern in detecting adverse effects on the soil microbiome.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109732"},"PeriodicalIF":9.8,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A legume-grass cover crop builds mineral-associated organic matter across variable agricultural soils","authors":"R. Kent Connell ,&nbsp;Timothy Y. James ,&nbsp;Jennifer Blesh","doi":"10.1016/j.soilbio.2025.109726","DOIUrl":"10.1016/j.soilbio.2025.109726","url":null,"abstract":"<div><div>Soil organic matter (SOM) fractions convey unique functions in agroecosystems, but the degree to which cover crops build multiple fractions of SOM and increase soil C storage is understudied. Particulate organic matter (POM) releases nutrients through microbial decomposition, whereas mineral-associated organic matter (MAOM) is associated with long-term C storage. We conducted a greenhouse experiment using ¹³C to trace the transfer of C from four cover crop treatments – cereal rye (<em>Secale cereale</em>), crimson clover (<em>Trifolium incarnatum</em>), a rye-clover mixture, and a no cover crop fallow – into these two SOM fractions in soils from 10 working farms that varied in texture, management history, and soil microbial communities. On average, MAOM C was 7.4% higher in the mixture treatment than in the fallow; however, this was not a significantly greater increase than in the cereal rye treatment. The amount of C transferred to MAOM and POM increased with cover crop biomass and soil C content, and was also moderated by fungal community composition. When compared to the rye treatment, the mixture provided a threefold greater transfer of C and a 2% greater transfer of nitrogen from POM to the more stable MAOM fraction, which is associated with long-term C sequestration. Overall, our results suggest that cover crop mixtures are a useful management strategy to increase agroecosystem multifunctionality. When grown in soils with high biological activity, mixtures can simultaneously stabilize C in soil while also increasing internal N cycling capacity of agroecosystems.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109726"},"PeriodicalIF":9.8,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035148","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":"Stability of iron-carbon complexes determines carbon sequestration efficiency in iron-rich soils","authors":"Xun Duan ,&nbsp;Zhe Li ,&nbsp;Shuang Wang ,&nbsp;Kyle Mason-Jones ,&nbsp;Liang Wei ,&nbsp;Xiangbi Chen ,&nbsp;Jinshui Wu ,&nbsp;Tida Ge ,&nbsp;Zhenke Zhu","doi":"10.1016/j.soilbio.2025.109718","DOIUrl":"10.1016/j.soilbio.2025.109718","url":null,"abstract":"<div><div>The role of iron minerals in soil organic carbon (SOC) stabilization has attracted considerable attention. However, the turnover of Fe-bound organic carbon (Fe–OC) complexes and their impact on the other organic C fractions in natural soils remain unclear, hindering accurate assessments of their C sequestration potential. To address this gap, we prepared 2- and 6-line ferrihydrite-bound ¹³C-glucose (2LFh-Glc and 6LFh-Glc, respectively) with five C loading levels, using free ¹³C-glucose as control. Our aim was to trace and quantify glucose mineralization, SOC priming effects, and net C balance in anaerobic Fe-rich paddy soils. Fh-Glc mineralization and its SOC priming were lower than those of free glucose. Mineralization and SOC priming of 6LFh-Glc were 29% and 67% lower, respectively, compared to 2LFh-Glc. This was attributed to the stronger protective ability of 6LFh for organic C, which limits glucose release and microbial accessibility, thereby inhibiting SOC mineralization. 6LFh-Glc showed 51% higher C sequestration efficiency than 2LFh-Glc (i.e., net soil C balance produced by per unit of C loading). Notably, C sequestration efficiency decreased with increasing C loading. In conclusion, both stability and C loading of Fe-OC complexes are key determinants of C sequestration efficiency in Fe-rich paddy soils, highlighting the importance of Fe-organic C associations in soil C sequestration.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109718"},"PeriodicalIF":9.8,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143035167","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":"Root exudates from drought-affected plants increase soil respiration across a range of grassland species","authors":"Fangbin Hou,&nbsp;Leonardo Hinojosa,&nbsp;Eileen Enderle,&nbsp;Boris Jansen,&nbsp;Elly Morriën,&nbsp;Franciska T. de Vries","doi":"10.1016/j.soilbio.2025.109731","DOIUrl":"10.1016/j.soilbio.2025.109731","url":null,"abstract":"<div><div>Root exudates play an important role in ecosystem carbon (C) cycling. Drought can alter the quality and quantity of root exudation, but it is not clear how root traits affect these changes, and what the implications are for soil C cycling. Seventeen common grassland species of three functional groups were subjected to a two-week drought followed by one week of recovery, after which root exudates were collected and analysed for their total C content, as well as for the respiration they triggered. Across all species but especially in legumes, drought increased specific root exudate-induced respiration rates. Both specific root exudation rate and specific respiration rate were positively correlated to root diameter and root nitrogen content, implying a link with “outsourcing” and “fast” strategies, and this correlation was strengthened after drought. These findings suggest that increased specific respiration rates as a result of drought-induced changes in root exudation is a plant strategy for coping with drought that may result in a loss of soil C after a drought has ended. These findings may help understand the impacts of drought on the capacity of soils to store C, and offer insight into the role of plants in this process.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109731"},"PeriodicalIF":9.8,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rotational diversity shapes the bacterial and archaeal communities and confers positive plant-soil feedback in winter wheat rotations","authors":"Nikolaos Kaloterakis ,&nbsp;Adriana Giongo ,&nbsp;Andrea Braun-Kiewnick ,&nbsp;Mehdi Rashtbari ,&nbsp;Priscilla Zamberlan ,&nbsp;Bahar S. Razavi ,&nbsp;Kornelia Smalla ,&nbsp;Rüdiger Reichel ,&nbsp;Nicolas Brüggemann","doi":"10.1016/j.soilbio.2025.109729","DOIUrl":"10.1016/j.soilbio.2025.109729","url":null,"abstract":"<div><div>Plant-soil feedbacks drive productivity in winter wheat (WW; <em>Triticum aestivum</em> L.) rotations. Although this is a frequent observation, the underlying plant-soil-microbe interactions remain unclear. We aimed to investigate the effects of WW rotational positions on soil bacterial and archaeal communities, as well as nitrogen (N) cycling, as potential drivers of WW yield decline in successively-grown WW. WW following oilseed rape (W1; <em>Brassica napus</em> L.) was compared with WW in self-succession (W2) in a rhizotron study using agricultural soil with a sandy loam texture. Samples were collected at tillering and grain ripening. At tillering, we found a higher NO₃⁻ content in W1 soil, especially in the 60–100 cm subsoil layer, associated with the N-rich residues of the preceding oilseed rape crop, while this trend was reversed at grain ripening. Analysis of enzyme kinetics revealed an increase in leucine aminopeptidase activity in W1 and an increase in β-glucosidase activity in W2 at tillering, possibly related to the residue quality of the preceding crop. No differences in bacterial and archaeal alpha diversity were observed at both sampling times, but beta diversity showed a significant role of both rotational position and soil depth in shaping the microbial community. The gene copy numbers of <em>amoA</em> genes of ammonia-oxidizing bacteria (AOB), <em>nifH</em> and <em>nirS</em> were significantly higher in W2 compared to W1 at tillering, suggesting a strong effect of rotational position on N cycling of the following WW. The abundances of <em>amoA</em> (AOB) and <em>nirS</em> were also higher in W2 at grain ripening<em>.</em> Our results highlight the persistent soil legacy of the preceding crop on both nutrient cycling and bacterial and archaeal community composition, contributing to yield reduction in successively grown WW. Understanding plant-microbe interactions and keeping them at the center of productive WW rotations is, and will continue to be, critical to future agriculture.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109729"},"PeriodicalIF":9.8,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143031094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fundamental shifts in soil and sediment microbial communities and functions during 10 year of early catchment succession","authors":"José Schreckinger ,&nbsp;Michael Mutz ,&nbsp;Mark O. Gessner ,&nbsp;Linda Gerull ,&nbsp;Aline Frossard","doi":"10.1016/j.soilbio.2025.109713","DOIUrl":"10.1016/j.soilbio.2025.109713","url":null,"abstract":"<div><div>Knowledge on microbial community shifts during ecosystem succession from bare surfaces resulting from massive landscape stripping is extremely limited. Here we took advantage of an artificially created experimental catchment (6 ha) to assess structural and functional changes of microbial communities in ephemeral stream sediments and adjacent soils between 3 and 13 years after catchment construction. The catchment has since developed in undisturbed conditions, with major transformations in its morphology, hydrology and vegetation reflected by changes in microbial community structure and function. Initially dominated by cyanobacteria (42% of 16S rRNA reads in 2008 and 0.3% in 2018), the bacterial community shifted to an essentially heterotrophic composition within 10 years, when Alphaproteobacteria (12 vs 21%) and Planctomycetes (3 vs 16%), in particular, gained in importance. Similarly, Sordariomycetes (5% of ITS reads in 2008 and 27% in 2018) replaced Dothideomycetes (53 vs 14%) as the prevailing fungal class. Microbial respiration rates increased tenfold, from an average of 0.5–4.4 μg CO₂ g⁻¹ DM h⁻¹, accompanied by an increase in potential enzyme activities. Seasonal patterns of microbial community functions were accentuated over a decade of catchment development, whereas structural community changes were less pronounced. Spatial variation of community composition also increased, with differences between soils and sediments intensifying over time. However, a striking disconnect between microbial community structure and function in 2008 had vanished by 2018. Thus, a decade of ecosystem succession resulted in fundamental shifts in microbial community structure and function, highlighting the intricate interplay between changing environmental conditions and microbial responses.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109713"},"PeriodicalIF":9.8,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142990658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Adult body mass influences multi-element stoichiometry in ground beetles","authors":"Bing Zhang ,&nbsp;Xin Li ,&nbsp;Haozhen Chen ,&nbsp;Mingqin Deng ,&nbsp;Haijun Xiao ,&nbsp;Shikui Dong ,&nbsp;Stefan Scheu ,&nbsp;Shaopeng Wang","doi":"10.1016/j.soilbio.2025.109716","DOIUrl":"10.1016/j.soilbio.2025.109716","url":null,"abstract":"<div><div>The element composition of organisms is crucial to their survival and growth, as well as their ecological functions. Although variations in carbon (C), nitrogen (N), and phosphorus (P) among species have been well documented, knowledge on whether such variations also exist within species and hold for other elements is limited. Within species, variations in element concentrations may arise from differences in individual traits (e.g., body mass) or heterogeneities in environmental conditions. To explore whether body mass and environment interactively affect intraspecific multi-element composition, we examined the concentrations of 11 elements (C, N, P, S, K, Ca, Na, Mg, Zn, Mn, and Cu) in 114 individuals from three ground beetle species surveyed in four forest types (poplar, oak, larch and oak-larch mixed forest). We investigated among- and within-species variation in each individual element and in the multi-element composition. Our results showed that (i) across all beetle individuals, body mass and species identity explained most of the variation in the concentrations of most elements, whereas forest type only played a minor role; (ii) within each beetle species, the concentration of C increased with body mass, while those of other elements tended to decrease; and (iii) multidimensional stoichiometric analyses also revealed large variations within species, which were again largely explained by variation in body mass and additionally by forest type. By revealing substantial variation in element composition within species and the role of body mass in driving this variation, our study provides empirical evidence supporting theoretical modeling of stoichiometry and new insights for integrating morphological and stoichiometric traits.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109716"},"PeriodicalIF":9.8,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988982","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":"Impact of graphite nano amendments on soil enzyme activities, functional genes and microbiome composition in a soil-plant system","authors":"Partho Das ,&nbsp;Claire Barker ,&nbsp;Yujin Park ,&nbsp;François Perreault ,&nbsp;Paul Westerhoff ,&nbsp;C Ryan Penton","doi":"10.1016/j.soilbio.2025.109714","DOIUrl":"10.1016/j.soilbio.2025.109714","url":null,"abstract":"<div><div>Graphite nano additive (GNA) has shown potential for enhanced soil N retention and plant productivity. To obtain mechanistic understanding on such beneficial effects, lettuce (<em>Lactuca sativa</em>) was grown in a greenhouse with an exposure of GNA at an application range of 0–500 mg/kg soil for seven weeks. Changes in microbial enzyme activities, N cycling gene abundances, and bacterial community composition were investigated as responses to GNA addition. GNA doses ≤100 mg/kg soil resulted in elevated soil microbial biomass carbon at week 3 and contributed to enhanced plant yield during the final harvest at week 7. GNA significantly influenced rhizosphere soil enzyme activities, with notable increases observed across all assayed enzymes at week 5, corresponding to the peak in lettuce growth. GNA addition decreased bacterial <em>amoA</em> abundance, which indicated suppressed soil nitrification potentials in both the bulk and rhizosphere soils. This was coupled with an increase in <em>nifH</em>-harboring bacteria in the bulk, but not rhizosphere, soil. Although the gene that encodes for the terminal step in denitrification (<em>nosZ</em>) was not significantly impacted, <em>nirS</em> and <em>nirK</em> abundances indicated a potential for enhanced denitrification in the bulk soil and suppression of denitrification in the rhizosphere soil. <em>16S rRNA</em> gene-based abundances indicated no significant decreases in the total bacterial community with GNA amendment in both the bulk and rhizosphere soils which indicates that GNA had limited microbiocidal effect on the broad community. However, GNA imposed selection for certain microbial functional clades and taxonomic lineages and demonstrated a significant impact on the overall composition of the microbial community. GNA demonstrated the potential to augment several beneficial bacterial groups while suppressing others. Overall, these data indicate that GNA significantly impacted the bacterial composition, potential N cycling, and enzyme-based activities of the soil community in a fashion that positively impacted the growth of lettuce in our study, principally within the plant rhizosphere.</div></div>","PeriodicalId":21888,"journal":{"name":"Soil Biology & Biochemistry","volume":"203 ","pages":"Article 109714"},"PeriodicalIF":9.8,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988983","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}