Applied Soil Ecology最新文献

{"title":"Niche differentiation shapes the community assembly of fungi associated with evergreen trees in the Horqin desert","authors":"Xuan Liu ,&nbsp;Pei-shan Zhao ,&nbsp;Guang-lei Gao ,&nbsp;Yue Ren ,&nbsp;Guo-dong Ding ,&nbsp;Ying Zhang","doi":"10.1016/j.apsoil.2024.105739","DOIUrl":"10.1016/j.apsoil.2024.105739","url":null,"abstract":"<div><div>Fungal communities inhabit plant soil and roots, occupying different niches. Soil fungi (SF) and root-associated fungi (RAF) strongly affect plant health and growth. Owing to the regulation of deterministic and stochastic processes, the community assembly of SF and RAF may exhibit spatiotemporal differences. Moreover, stand age affects the fungal community distribution, soil properties, and the understorey microenvironment in desert forest ecosystems. However, little is known about the underlying mechanisms by which stand age shapes the SF and RAF community assemblies in desert forest ecosystems. Therefore, we collected soil and root samples of Mongolian pine (<em>Pinus sylvestris</em> var. <em>mongolica</em>) from five stands (13a (young), 22a (half-mature), 34a (nearly mature), 41a (mature), and 55a (overmature)) in the Horqin Desert to reveal the community assembly of SF and RAF associated with Mongolian pine plantations. The results indicate that (1) stand age affected the diversity, responsive taxa, and composition of SF rather than those of RAF. (2) RAF communities were more stable than SF communities were, and the community stability of the SF and RAF communities was influenced mainly by symbiotroph_saprotroph fungi and symbiotroph_pathotroph_saprotroph fungi, respectively. (3) Compared with the RAF communities, the SF communities presented wider niche breadth (<em>p</em> &lt; 0.001) and lower niche overlap (<em>p</em> &lt; 0.05). Dispersal limitation (75.33 %) and ecological drift (58.33 %) played crucial roles in controlling the respective SF and RAF community assemblies. (4) The community assembly of the SF and RAF communities was affected mainly by soil moisture and soil nutrients. The response of the SF community composition (<em>p</em> &lt; 0.001) to stand age was stronger than that of the RAF community composition (<em>p</em> &lt; 0.05). The results reveal that stand age had a stronger effect on SF community characteristics and community assembly processes than on those of RAF. These studies help elucidate the differences in fungal communities in different niches of desert ecosystems. Understanding the responses of SF and RAF communities to stand age may improve the understanding of the potentially profound consequences of stand age on microbiome function in desert forest ecosystems.</div></div>","PeriodicalId":8099,"journal":{"name":"Applied Soil Ecology","volume":"204 ","pages":"Article 105739"},"PeriodicalIF":4.8,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697261","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}

{"title":"Organic materials return suppressed soil N2O emissions by changing the composition instead of abundance of denitrifying microbial community","authors":"Lin Chen ,&nbsp;Qing Liu ,&nbsp;Hailun Du ,&nbsp;Jixiao Cui ,&nbsp;Yuanquan Chen","doi":"10.1016/j.apsoil.2024.105759","DOIUrl":"10.1016/j.apsoil.2024.105759","url":null,"abstract":"<div><div>Organic materials returned to the field have a significant effect on N₂O emissions from agricultural fields, but the knowledge about the relationship between soil denitrifying microorganisms and N₂O emissions is limited. Hence, we delved deeper into the significance of denitrifying microorganisms in N2O emissions by examining the soil N2O emissions, gene copy numbers, and community structures of denitrifying microorganisms during the wheat harvest season, three years after the partial substitution of chemical nitrogen fertilizers with various organic materials, including straw, pig manure, and biogas residues. The results showed that compared with chemical fertilizer, straw return did not change N₂O emission, and pig manure and biogas residue, especially pig manure return, significantly reduced N₂O emission (62 % and 45 %). Organic materials return did not change the gene copy number of denitrifying microorganisms, but had a significant effect on the community structure. The relative abundance of genera in the three organic materials treatments differed significantly from the chemical fertilizer treatment. The pig manure treatment had marker genera in the <em>nosZ</em> gene. Among the <em>nirK</em>, <em>nirS</em>, and <em>nosZ</em> genes, <em>Sinorhizobium</em>, <em>norank_p_environment_samples</em>, and <em>unclassified_k_norank_d_bacteria</em>, respectively, had the greatest effect on N₂O emissions. The results of the RDA and the minimum depth method indicated that K, pH, and SOC were the key environmental factors influencing the structural changes of <em>nirK</em>, <em>nirS</em> and <em>nosZ</em> communities. Overall, organic materials, especially pig manure, effectively suppressed N₂O emissions by changing the relative abundance and community structure of the dominant genera of denitrifying microorganisms.</div></div>","PeriodicalId":8099,"journal":{"name":"Applied Soil Ecology","volume":"204 ","pages":"Article 105759"},"PeriodicalIF":4.8,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697322","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}

{"title":"Impacts of long-term organic fertilization on metabolomic and metagenomic characteristics of soils in a greenhouse vegetable production system","authors":"Yun-Cheng Hsieh ,&nbsp;Chun-Han Su ,&nbsp;Tzung-Han Lee ,&nbsp;Lean-Teik Ng","doi":"10.1016/j.apsoil.2024.105738","DOIUrl":"10.1016/j.apsoil.2024.105738","url":null,"abstract":"<div><div>Organic fertilization is popular in the greenhouse vegetable farming system. This study aimed to examine the impacts of long-term fertilization of various animal and plant waste composts on chemical properties, and the characteristics of metabolomics and metagenomics of soils in a greenhouse vegetable production system. The results showed that after 20 years of continuous organic fertilization, the soil pH was reduced in all treatments except pig and chicken dung composts; the most significant reduction was in the plant waste compost-treated soils. The soil electrical conductivity value, organic matter content, and the availability of phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) increased with organic fertilizer applications. The annual yields of leafy vegetables for all treatments were relatively stable. Among them, the yield of soybean meal compost (Soy)-treated soils was the lowest. Unique metabolomic and metagenomic profiles were noted in the five different treatments, and they were significantly different between animal and plant waste compost-treated soils. The relative abundance of nucleotide-related metabolites, such as pyrimidones, purinones, and 6-aminopurines, was higher in the high-yield treatments. The relative abundance of <em>Bacillus</em> and <em>Neobacillus</em> was negatively correlated with the total nitrogen content of the soil. In addition, <em>Bacillus aryabhattai</em> was a strain present in all compost-treated soils, but its relative abundance was higher in the control (unfertilized) and Soy-treated soils. This study suggests that the combination of metabolomics and metagenomics could be used to examine soil quality and function, which is a more comprehensive assessment strategy and may facilitate agricultural management.</div></div>","PeriodicalId":8099,"journal":{"name":"Applied Soil Ecology","volume":"204 ","pages":"Article 105738"},"PeriodicalIF":4.8,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697259","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}

{"title":"Nitrifying and denitrifying microbes exhibit distinct community structure and activity responses to different crop rotation systems in subtropical paddy soils","authors":"Huifang Xu ,&nbsp;Ke Li ,&nbsp;Rong Sheng ,&nbsp;Hongling Qin ,&nbsp;Yi Liu ,&nbsp;Anlei Chen ,&nbsp;Haijun Hou ,&nbsp;Baoli Zhu ,&nbsp;Wenxue Wei ,&nbsp;Wenzhao Zhang","doi":"10.1016/j.apsoil.2024.105754","DOIUrl":"10.1016/j.apsoil.2024.105754","url":null,"abstract":"<div><div>The adverse impacts of double-season rice cultivation on soil health and crop yield can be alleviated by crop rotation. However, the mechanisms by which biotic and abiotic factors influence microbial nitrogen cycling under different crop rotation systems remain unclear. Here, we evaluated the impact of crop rotation in paddy soils on the community abundance, composition, and activity of nitrifying microbes (ammonia-oxidizing archaea and bacteria (AOA and AOB)) and denitrifying microbes (<em>nirK</em>- and <em>nirS</em>-denitrifiers). A 6-year field experiment was performed with four crop rotation systems: (1) double rice as a control, (2) middle-season rice–fallow rotation (MR), (3) middle-season rice–oilseed rape rotation (MROR), and (4) middle-season rice–pak choi–oilseed rape rotation (MRPOR). AOB abundance increased significantly in MROR and MRPOR treatments, whereas AOA abundance decreased significantly in MROR. <em>nirS</em> gene abundance was significantly lower in MROR and MRPOR treatments, whereas <em>nirK</em> gene abundance was significantly lower in MR and MRPOR treatments. AOB and <em>nirK</em> gene community structures were significantly altered by crop rotation; this relationship was closely correlated with soil water content and NO₃⁻-N concentration. For MROR and MRPOR treatments, potential nitrification activity was significantly increased and positively correlated with AOB abundance, whereas denitrification enzyme activity was significantly decreased and correlated with <em>nirK</em> and <em>nirS</em> community structure. Therefore, nitrifiers and denitrifiers exhibit distinct responses to crop rotation in paddy soils, which may influence microbial nitrogen cycling. These findings have practical implications for selecting appropriate cropping regimes.</div></div>","PeriodicalId":8099,"journal":{"name":"Applied Soil Ecology","volume":"204 ","pages":"Article 105754"},"PeriodicalIF":4.8,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697323","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}

{"title":"Microbial mechanisms underlying active organic carbon pool increases via rhizodeposition by Moso bamboo under in situ crown 13CO2 enrichment","authors":"Man Shi ,&nbsp;Hang Chen ,&nbsp;Junbo Zhang,&nbsp;Zhenxiong Chen,&nbsp;Zhikang Wang,&nbsp;Tingting Cao,&nbsp;Quan Li,&nbsp;Xinzhang Song","doi":"10.1016/j.apsoil.2024.105756","DOIUrl":"10.1016/j.apsoil.2024.105756","url":null,"abstract":"<div><div>Plant rhizodeposition strongly mediates plant-soil-microbe interactions and impacts the soil active organic carbon (C) pool. However, the mechanisms by which rhizodeposition affects the modulation of soil active organic C pool remain poorly understood. In this study, we investigated the effects of rhizodeposition on active organic C pool and microbial communities in Moso bamboo (<em>Phyllostachys edulis</em>), a clonal plant with rhizome-connected mother and offspring ramets. The crown of the mother ramet was enriched with ¹³CO₂ to trace rhizodeposition and assess changes in soil organic C pool and the microbial community across different root systems (culm roots and rhizome roots) during key growth stages (early, peak, branching, and leafing). Our results showed that crown CO₂ enrichment increased δ¹³C and the contents of microbial biomass C, dissolved organic C, and labile organic C (by 22.08 % to 43.67 %) in the rhizosphere, which significantly altered the bacterial community composition. Under crown CO₂ enrichment, the abundance of bacterial taxa and genes associated with recalcitrant C decomposition decreased by 29.08 %–77.38 % and 30.75 %–56.85 %, respectively; while taxa and genes related to CO₂ fixation increased by 51.22 %–267.00 % and 92.52 %–331.46 %, respectively. These microbial shifts contributed to an increase in the soil active organic C pool. In addition, the growth stage, rather than the root system, had a greater influence on rhizodeposition, with higher δ¹³C observed during the early and leafing stages compared to the peak and branching stages. In conclusion, our findings suggest that increases in the active organic C pool were primarily driven by enhanced C rhizodeposition, the stimulation of microbes involved in CO₂ fixation, and the suppression of bacteria involved in recalcitrant C decomposition, while being highly dependent on the growth stage. This study provides valuable insights into the interactions between plant rhizodeposition, microbial functions, and soil active organic C dynamics.</div></div>","PeriodicalId":8099,"journal":{"name":"Applied Soil Ecology","volume":"204 ","pages":"Article 105756"},"PeriodicalIF":4.8,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697260","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}

{"title":"Soil pore structure shaped compositions and structures of soil microbial community during 13C-labelled maize straw decomposition","authors":"Tianyu Ding ,&nbsp;Rui Qian ,&nbsp;Zichun Guo ,&nbsp;Xianjin Huang ,&nbsp;Xinhua Peng","doi":"10.1016/j.apsoil.2024.105746","DOIUrl":"10.1016/j.apsoil.2024.105746","url":null,"abstract":"<div><div>Soil pore structure regulates water movement, gas exchange and determines the heterogeneous distribution of nutrients, thereby exerting significant influence on microorganisms. However, the specific contributions and limitations of pores of different sizes on soil microbial communities during straw decomposition, as well as the variations in pore structure throughout this process, remain unknown. To address this, a 57-day soil incubation experiment was conducted, using ¹³C-labelled maize straw with two soil types: Shajiang black soil (Vertisols) and Fluvo-aquic soil (Cambisols). The experiment was set at two bulk densities: 1.2 g cm⁻³ and 1.5 g cm⁻³. The variations in pore structure before and after the incubation experiment were quantified using X-ray micro-computed tomography (μCT). To analyze microbial C content from straw, ¹³C-Phospholipid fatty acids (¹³C-PLFAs) were used, and 16S rDNA high-throughput sequencing was employed to determine bacterial community structure after the incubation. The resulted showed that Shajiang black soil exhibited a 50.5 % increase of total PLFA-C content from straw than Fluvo-aquic soil at a bulk density of 1.5 g cm⁻³ (<em>P</em> &lt; 0.05). Specifically, Gram-positive bacteria (G+), Gram-negative bacteria (G−) and actinobacteria PLFA-C content increased by 105.2 %, 55.0 % and 73.6 % (<em>P</em> &lt; 0.05). Redundancy analysis (RDA) showed that &gt;100 μm pores in diameter (Ø) facilitated the colonization of microorganisms (G+, G− and actinobacteria). Specifically, bacteria (including G+, G−, and common bacteria, accounted for 37.6 %, 15.7 % and 22.1 % of straw-derived PLFA-C in relation to the total amount of straw-enriched PLFA-C) were key contributors to straw decomposition and were associated with the formation of 50–200 μm Ø pores. Meanwhile, fungal activity was primarily responsible for changes in the 20–50 μm Ø pore structure. These findings emphasize that &gt;100 μm Ø pores created a favorable physical environment for microbial communities on straw decomposition, highlighting the pivotal role of microbial activity in shaping soil pore structure.</div></div>","PeriodicalId":8099,"journal":{"name":"Applied Soil Ecology","volume":"204 ","pages":"Article 105746"},"PeriodicalIF":4.8,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697262","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}

{"title":"Soil characteristics drive contrasting patterns of association between symbiotic rhizobia of endemic and widespread Mimosa species in Brazil","authors":"Luc Rouws ,&nbsp;Alexandre Barauna ,&nbsp;Chrizelle Beukes ,&nbsp;Janaina R.C. Rouws ,&nbsp;Sergio Miana de Faria ,&nbsp;Eduardo Gross ,&nbsp;Fabio Bueno dos Reis Junior ,&nbsp;Marcelo F. Simon ,&nbsp;Marta Maluk ,&nbsp;David W. Odee ,&nbsp;Stephanie Fordeyn ,&nbsp;Gregory Kenicer ,&nbsp;J. Peter W. Young ,&nbsp;Veronica M. Reis ,&nbsp;Jerri Zilli ,&nbsp;Euan K. James","doi":"10.1016/j.apsoil.2024.105741","DOIUrl":"10.1016/j.apsoil.2024.105741","url":null,"abstract":"<div><div>Neotropical Beta-rhizobia have a particular affinity to the large legume (Fabaceae) genus <em>Mimosa</em> and some of its relatives in the tribe Mimosae of the Caesalpinioideae subfamily. However, little is still known about the ecology of this interaction, especially the relationship between the rhizobia of “widespread” pan-tropical <em>Mimosa</em> species like <em>M. pudica</em> and the rhizobia that nodulate endemic <em>Mimosa</em> species that are very restricted in their habitats. The objective of this study was to examine the microsymbionts of <em>Mimosa</em> spp. and other mimosoids in climates ranging from tropical to subtropical, humid to semi-arid, with varied soil characteristics and altitudes, with the aim of testing the hypothesis that widespread species have more cosmopolitan symbiont preferences than endemic ones. Nodules were sampled from &gt;30 <em>Mimosa</em> spp. and related taxa in 13 Brazilian states covering all five national regions; many of the species were endemics or biome-restricted, but particular attention was also paid to sample nodules from the widespread species <em>M. pudica</em> at all locations. The <em>Mimosa</em> symbionts comprised 21 potential 16S rRNA and <em>recA</em> groups at the species level, with 17 belonging to the genus <em>Paraburkholderia</em>, including four lineages that may represent new species. The remaining genotypes consisted of 14 strains in two lineages of <em>Cupriavidus</em> that were mainly isolated from <em>M. pudica</em> growing at low altitudes, and a single lineage of <em>Rhizobium</em> also from <em>M. pudica</em>. In addition, a strain of <em>Trinickia symbiotica</em> was isolated from <em>M. misera</em>. It is concluded that diverse genotypes of <em>Paraburkholderia</em> dominate as symbionts of <em>Mimosa</em> in the acidic soils of its main center of radiation in Central Brazil but that <em>Cupriavidus</em> and <em>Rhizobium</em> comprise a significant minority of symbionts of widespread <em>Mimosa</em> spp., especially <em>M. pudica</em>, in lowland or disturbed areas with less acidic soils. <em>Mimosa</em> symbiont selection is thus driven either by edapho-climatic characteristics for widespread species and/or by co-evolution of the symbiotic partners for endemic species.</div></div>","PeriodicalId":8099,"journal":{"name":"Applied Soil Ecology","volume":"204 ","pages":"Article 105741"},"PeriodicalIF":4.8,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697231","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}

{"title":"Relative to rainforests and grasslands, banana and sugarcane soils have half the microbial biomass and highly distinct bacterial and fungal communities","authors":"Henry W.G. Birt ,&nbsp;Anthony B. Pattison ,&nbsp;Yolima Carrillo ,&nbsp;Scott N. Lieske ,&nbsp;Rebecca Lyons ,&nbsp;Hazel R. Lapis-Gaza ,&nbsp;Jiarui Sun ,&nbsp;Paul G. Dennis","doi":"10.1016/j.apsoil.2024.105750","DOIUrl":"10.1016/j.apsoil.2024.105750","url":null,"abstract":"<div><div>Soil microbial communities mediate a range of ecosystem services and are impacted by land use. The Wet Tropics region of north Queensland, Australia, is a biodiversity hotspot with some of the world's oldest rainforests, but also has large areas converted for agriculture. We explored soil abiotic and biotic characteristics in 86 sites across four of the key land uses in this area: banana production, sugarcane production, grassland, and rainforest. Furthermore, we characterised sites where wild bananas were found in rainforests to bridge the associations found in natural and agricultural areas. Soil abiotic and biotic characteristics were found to differ between landuses, with commercial banana soils being the most distinct. Commercial banana and sugarcane soils had less soil carbon, and banana soils were also less acidic and had higher zinc and nitrate levels than other landuses. Interestingly, banana and sugarcane soils had half the microbial biomass of other landuses, including wild banana. The diversity of soil bacterial and fungal communities was also highly distinct in commercial banana soils, with significantly larger relative abundances of <em>Fusarium oxysporum</em>, a fungal species complex that includes important plant pathogens. Differences in soil biotic characteristics between landuses were significantly correlated with soil carbon, nitrogen, phosphorus, and pH. Our results demonstrate that land management can profoundly impact soil microbial communities, with potential consequences for ecosystem functioning.</div></div>","PeriodicalId":8099,"journal":{"name":"Applied Soil Ecology","volume":"204 ","pages":"Article 105750"},"PeriodicalIF":4.8,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697263","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}

{"title":"Long-term effects of film mulching and fertilization regimes on gross N transformations in calcareous dryland soils","authors":"Na Gao ,&nbsp;Ting Zhang ,&nbsp;Zhaoyang Li ,&nbsp;Xiaofan Tian ,&nbsp;Jiayu Chen ,&nbsp;Jinbo Zhang ,&nbsp;Christoph Müller ,&nbsp;Shiqing Li","doi":"10.1016/j.apsoil.2024.105747","DOIUrl":"10.1016/j.apsoil.2024.105747","url":null,"abstract":"<div><div>Plastic film mulching (PM) and nitrogen (N) fertilization regimes significantly affect crop yield, N supply capacity, and N losses. However, the long-term effects and the underlying mechanisms, like the belowground N transformations, call for in-depth investigation. Here, a ¹⁵N tracing study was conducted to quantify the gross N transformation rates of the calcareous soil subjected to 12 years of PM and various fertilization regimes. We found that autotrophic nitrification (<em>O</em>_<em>NH4</em>) and mineralization (<em>M</em>) were the predominant soil N conversion processes, while dissimilatory nitrate reduction to ammonium (<em>DNRA</em>) and nitrate immobilization (<em>I</em>_<em>NO3</em>) were negligible in the calcareous soil, leading to the accumulation of nitrate. Long-term PM significantly decreased the rates of <em>M</em>, recalcitrant organic-N mineralization (<em>M</em>_{<em>Nrec</em>}), <em>O</em>_<em>NH4</em>, and NH₄⁺ immobilization to labile organic-N (<em>I</em>_{<em>NH4_Nlab</em>}) due to the negative effect on the abundances of fungi and ammonia-oxidizing bacteria (AOB) <em>amoA</em> gene compared to control soil. Relative to no N control, different fertilization regimes significantly increased the AOB <em>amoA</em> gene abundance, decreased fungal abundance and ITS:16S ratio, thus increasing <em>O</em>_<em>NH4</em> and <em>M</em>, decreasing NH₄⁺ immobilization rates to labile and recalcitrant organic-N<em>.</em> Compared to normal N rate (F₂₂₅), high N rate (F₃₈₀) and normal N plus manure (F_225+M) markedly increased <em>O</em>_<em>NH4</em> and <em>I</em>_<em>NO3</em>. Regression analyses revealed that <em>M</em> and AOB <em>amoA</em> gene abundance affected <em>O</em>_<em>NH4</em>, and in turn N₂O production. The findings provide an improved understanding of the long-term effects of PM and N managements on soil N supply capacity and potential N losses based on internal N cycling and molecular biology.</div></div>","PeriodicalId":8099,"journal":{"name":"Applied Soil Ecology","volume":"204 ","pages":"Article 105747"},"PeriodicalIF":4.8,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697230","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}

{"title":"Ecotypes shape extracellular enzyme stoichiometries via microbial resource allocation","authors":"Kaikai Min ,&nbsp;Laurel Lynch ,&nbsp;Xuefeng Zhu ,&nbsp;Fusheng Chen ,&nbsp;Chao Liang","doi":"10.1016/j.apsoil.2024.105744","DOIUrl":"10.1016/j.apsoil.2024.105744","url":null,"abstract":"<div><div>Microorganisms allocate resources toward extracellular enzyme production in order to acquire limiting nutrients from complex organic matter. However, it remains unclear whether exoenzymatic stoichiometries (e.g., ratios between carbon-, nitrogen-, and/or phosphorus-acquiring enzymes) vary between natural and managed ecosystems. Accordingly, we assessed relationships between microbial community composition, exoenzymatic stoichiometries, and life history strategies (e.g., copiotrophs versus oligotrophs) in old growth forest and cropland soils. We found that cropland soils were associated with more abundant copiotrophic taxa, lignin degradation, and higher activities of nitrogen-acquiring and oxidative enzymes, while forest soils were associated with more abundant oligotrophic taxa, cellulose turnover, and larger microbial biomass pools. Two keystone taxa, <em>Basidiomycota</em> and <em>Alphaproteobacteria</em>, played strong roles in regulating exoenzymatic stoichiometries across both ecosystems. Notably, co-occurrence network analysis suggested relationships between exoenzymatic stoichiometries and microbial life-history strategies were stronger in disturbed cropland soils than old growth forest soils. Based on these results, we suggest increasing the quantity and diversity of organic matter inputs to cropland soils, while protecting forest soils through adaptive management practices, could enhance carbon flows through the microbial loop and promote soil organic carbon sequestration. Incorporating exoenzymatic stoichiometries into trait-based frameworks could further improve our ability to predict how changes in microbial community structure scale up to influence ecosystem function.</div></div>","PeriodicalId":8099,"journal":{"name":"Applied Soil Ecology","volume":"204 ","pages":"Article 105744"},"PeriodicalIF":4.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653366","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}