Pedosphere最新文献

{"title":"Brackish water irrigation-induced recruitment of specific consortium determines microbial resistance that facilitates crop yield in a field experiment","authors":"Qingxia WANG ,&nbsp;Jisheng XU ,&nbsp;Dandan LI ,&nbsp;Yunpeng ZHOU ,&nbsp;Meiqi CHEN ,&nbsp;Xiying ZHANG ,&nbsp;Jiabao ZHANG ,&nbsp;Bingzi ZHAO","doi":"10.1016/j.pedsph.2024.07.005","DOIUrl":"10.1016/j.pedsph.2024.07.005","url":null,"abstract":"<div><div>Crop productivity may be affected by soil salinization from brackish water irrigation. Plants host species-specific soil microorganisms that can enhance plant adaptability to salt stress. However, it is unclear whether these specific microorganisms recruited under brackish water irrigation are related to microbial resistance, which has been proven to promote crop production. A field experiment was conducted using five local wheat varieties, each of which was exposed to brackish or fresh water irrigation for four years. Brackish water irrigation tended to increase wheat yield by 6.38%–19.40%, although the increase in yield under brackish water relative to fresh water irrigation varied with wheat variety. The compositions of the bacterial and fungal communities in the bulk soil and rhizosphere were measured, and the taxa enriched following brackish water irrigation were isolated to investigate microbial resistance. We found that the resistance of each wheat variety was determined by specifically recruited microbial taxa with relevant functions. The yield incremental rates were positively regulated by microbial resistance from the bulk soil and rhizosphere. Moreover, the resistance from the bulk soil and rhizosphere had similar effects, and microbial consortia containing both beneficial and harmful taxa determined microbial resistance. These results indicated that brackish water irrigation-induced recruitment of specific microbial taxa from either the bulk soil or the rhizosphere or both positively contributed to the yield incremental rate and provided a list of key taxa linked to the magnitude of yield variation caused by brackish water irrigation.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 5","pages":"Pages 820-833"},"PeriodicalIF":7.3,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141849616","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":"Co-inoculation of protist and Bacillus enhances plant growth via reshaping rhizosphere bacterial community composition and function","authors":"Qihui LÜ ,&nbsp;Chen LIU ,&nbsp;Ying GUI ,&nbsp;Yang YUE ,&nbsp;Xiao WANG ,&nbsp;Zeyuan ZHOU ,&nbsp;Ying YUAN ,&nbsp;Yijing WANG ,&nbsp;Boting XU ,&nbsp;Zhihui XU ,&nbsp;Mohammadhossein RAVANBAKHSH ,&nbsp;Alexandre JOUSSET ,&nbsp;Wu XIONG ,&nbsp;Qirong SHEN","doi":"10.1016/j.pedsph.2024.07.006","DOIUrl":"10.1016/j.pedsph.2024.07.006","url":null,"abstract":"<div><div>Plant growth-promoting rhizobacteria (PGPR) have been widely used for the promotion of plant performance. Predatory protists can influence the taxonomic and functional composition of rhizosphere bacteria. However, research on the impact of the interaction between protist and PGPR on plant performance remains at a very early stage. Here, we examined the impacts of individual inoculation of protist (<em>Colpoda inflata</em>, <em>Dimastigella trypaniformis</em>, or <em>Vermamoeba vermiformis</em>) or the PGPR strain <em>Bacillus velezensis</em> SQR9 as well as the co-inoculation of the protist <em>C. inflata</em> and <em>B. velezensis</em> SQR9 on the growth of tomato plants. We found that all individual protists and <em>Bacillus</em> could promote plant growth compared to the control with no microbe inoculation, with the co-inoculation of <em>C. inflata</em> and <em>B. velezensis</em> SQR9 achieving the greatest performance, including plant height, fresh weight, and dry weight. Different protists harbored distinct rhizosphere bacterial communities, with the co-inoculation of protist and <em>Bacillus</em> resulting in the lowest bacterial diversity and driving significant changes in community structure and composition, particularly by increasing the relative abundance of Proteobacteria. Random forest model highlighted <em>Cellvibrio</em> as the most important bacterial predictor of plant growth, which was enriched after protist inoculation, especially after the mixed inoculation of protist and <em>Bacillus</em>. We further found that bacterial functional genes of nitrogen metabolism were the key determinants of plant growth. These results indicate that the interaction between protists and <em>Bacillus</em> can support plant growth by reshaping rhizosphere bacterial community composition and function. Understanding the interaction mechanisms between protist and PGPR is crucial for their effective utilization in sustainable agriculture.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 5","pages":"Pages 893-900"},"PeriodicalIF":7.3,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141840106","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":"Improving Cd and Zn enrichment in leaf mustard (Brassica juncea) on heavy metal-contaminated soil using metal-activating probiotics","authors":"Qian LI ,&nbsp;Ping WANG ,&nbsp;Yiman LI ,&nbsp;Zhaowen YANG ,&nbsp;Xu YANG ,&nbsp;Kailin LIANG ,&nbsp;Yizhuo LIU ,&nbsp;Zehua WEN ,&nbsp;Shuqiang ZHANG ,&nbsp;Zengqiang ZHANG","doi":"10.1016/j.pedsph.2024.07.002","DOIUrl":"10.1016/j.pedsph.2024.07.002","url":null,"abstract":"<div><div>Microbe-assisted phytoremediation is of great significance for the remediation of soil contaminated with heavy metals (HMs), and probiotics are beneficial microorganisms that can improve soil structure and fertility and promote plant growth. However, there are few studies on probiotics applied to remediate soil contaminated with HMs, and whether probiotics can improve the efficiency of phytoremediation still needs to be further investigated. This study aimed to investigate the effects of two kinds of probiotics, <em>Lactobacillus casei</em> (<em>Lc</em>) and <em>Bacillus licheniformis</em> (<em>Bl</em>), on activating the remediation potential of leaf mustard, <em>Brassica juncea</em> (L.) Czerniak., for soil contaminated with Cd and Zn using incubation and pot experiments. The results showed that the addition of the two probiotics significantly reduced soil pH by 0.05–0.32 units and improved the available contents of soil HMs (by 15.3%–60.0% and 7.1%–23.8% for Cd and Zn, respectively) in the incubation experiment. After probiotic addition, available Cd and Zn contents in soil treated with 1×10⁹ colony forming units (cfu) mL^-1 <em>Bl</em> were 1.65- and 1.66-folds of those in the control without probiotic, respectively, in the pot experiment. Meanwhile, soil alkaline phosphatase, urease, and sucrose activities were increased, indicating that soil microbial metabolic activities were also stimulated. Addition of <em>Lc</em> and <em>Bl</em> significantly improved the biomass and chlorophyll contents of leaf mustard. The contents of Cd and Zn in shoots and roots were significantly increased in the treatment with 1×10⁵ cfu mL^-1 <em>Lc</em>. Furthermore, the activities of plant antioxidant enzymes, including superoxide dismutase, peroxidase, and catalase, were increased, and the content of plant malondialdehyde was reduced, indicating that the resistance of plants to HMs was enhanced. These results indicated that these two kinds of probiotics could enhance the availability of Cd and Zn directly in soil and promote the growth of leaf mustard, thereby increasing the efficiency of phytoremediation for HMs. The study provides a useful reference for probiotic-assisted phytoremediation of soil contaminated with HMs.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 5","pages":"Pages 858-868"},"PeriodicalIF":7.3,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141699520","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":"Insight into amelioration effect of iron-modified biochar on saline-alkali soil chemical properties and bacterial communities along a soil depth gradient","authors":"Jiyuan WANG ,&nbsp;Riaz MUHAMMAD ,&nbsp;Saba BABAR ,&nbsp;Zeinab El-DESOUKI ,&nbsp;Yuxuan LI ,&nbsp;Xiangling WANG ,&nbsp;Xiaoyang XIA ,&nbsp;Cuncang JIANG","doi":"10.1016/j.pedsph.2024.07.001","DOIUrl":"10.1016/j.pedsph.2024.07.001","url":null,"abstract":"<div><div>The application of modified biochar has been proven to be a novel and promising strategy to improve saline-alkali soil. However, the effect of iron-modified biochar (FB) on the chemical properties of saline-alkali soil at different depths remains unclear. Therefore, we designed a soil column and divided it into three consecutive parts (<em>i.e</em>., topsoil, middle soil, and subsoil) to explore the amelioration effects of biochar on saline-alkali soil chemical properties and bacterial communities along a depth gradient in the treatments amended with 0.5% (weight/weight) pristine biochar (PB), 1% (weight:weight) PB, 0.5% (weight:weight) FB, and 1% (weight:weight) FB and without biochar (control, CK). The results showed that soil chemical properties were significantly improved with 1% FB application, while the amelioration effect of FB was different between the topsoil and subsoil. The activities of extracellular enzymes significantly increased in the topsoil and base cations decreased in the subsoil in the FB treatment compared with CK. Moreover, the abundances of halophilic taxa were higher in the subsoil than in the topsoil, especially for Bacteroidetes and Deinococcota. Furthermore, the abundances of beneficial bacteria (<em>e.g</em>., c_Alphaproteobacteria, <em>Sphingomonas</em>, and <em>Pontibacter</em>) in saline-alkali soil increased in the FB treatment compared with CK. Our results suggest the ameliorative effect of FB on soil properties and bacterial communities along a soil depth gradient, providing a novel strategy for improving saline-alkali soil with biochar.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 5","pages":"Pages 879-892"},"PeriodicalIF":7.3,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141717010","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":"Accessing global soil raster images and equal-area splines to estimate soil organic carbon stocks on the regional scale","authors":"Trevan FLYNN ,&nbsp;Rosana KOSTECKI ,&nbsp;Ansa REBI ,&nbsp;Taqi RAZA","doi":"10.1016/j.pedsph.2024.07.004","DOIUrl":"10.1016/j.pedsph.2024.07.004","url":null,"abstract":"<div><div>Soil carbon stock research has gained prominence in environmental studies amidst climate change concerns, especially given that soil is one of the largest terrestrial carbon reserves. Accurate predictions necessitate comprehensive soil profile measurements, which are resource-intensive to obtain. To address this, depth functions are employed to derive continuous estimates, aligning with standardized depths. However, global datasets employing depth functions in raster format have not been widely utilized, which could lower financial costs and improve accuracy in data-scarce regions. Furthermore, research into aggregating depth functions for realistic carbon stock estimations remains limited, offering opportunities to streamline cost and time. The aim of this study was to apply equal-area splines to estimate soil carbon stocks, utilizing SoilGrids and iSDAsoil datasets in a 317-km² Quaternary catchment (30°48′ E, 29°18′ S) in KwaZulu-Natal, South Africa. Both datasets were resampled to a 250-m resolution, and the splines were interpolated to a depth of 50 cm per pixel. Various aggregation methods were employed in calculation, including the cumulative sum (definite integral), discrete sum (sum of 1-cm spline predictions), and the mean carbon stock (mean to 50 cm). Quantitative evaluation was performed with 310 external soil samples. SoilGrids showed higher predictions (100–546 kg m^-2) than iSDAsoil (66.9–225 kg m^-2) for the cumulative sum. The discrete sum also exhibited higher prediction values for SoilGrids (293–789 kg m^-2) compared to iSDAsoil (228–557 kg m^-2). SoilGrids aggregated with the discrete sum closely matched previous studies, estimating total carbon stock for the catchment at 7 126 t, albeit with spatial inconsistencies. However, when evaluating with an external dataset, the results were not satisfactory for any method according to Lin's concordance correlation coefficient (CCC, correlation of a 1:1 line), with all models obtaining a CCC below 0.01. Similarly, all models had a root mean squared error larger than 59 kg m^-2. It was concluded that SoilGrids and iSDAsoil were spatially inaccurate in the catchment but can still provide information about the total carbon stock. This method could be improved by obtaining more soil samples for the datasets, incorporating local data into the spline, making the method more computationally efficient, and accounting for discrete horizon boundaries.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 5","pages":"Pages 834-845"},"PeriodicalIF":7.3,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141693605","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 geography, climate, soil properties and vegetation characteristics on soil C:N and N:P stoichiometry across the Qinghai-Tibetan Plateau","authors":"Wenlan FENG ,&nbsp;Pierre MARIOTTE ,&nbsp;Jun GU ,&nbsp;Xiaodong SONG ,&nbsp;Jinling YANG ,&nbsp;Fei YANG ,&nbsp;Yuguo ZHAO ,&nbsp;Ganlin ZHANG","doi":"10.1016/j.pedsph.2024.06.012","DOIUrl":"10.1016/j.pedsph.2024.06.012","url":null,"abstract":"<div><div>Soil organic carbon (SOC):total nitrogen (TN):total phosphorus (TP) (C:N:P) stoichiometry can give important information about biogeochemical cycling in terrestrial ecosystems. The spatial patterns and driving mechanisms of soil C:N:P ratios are still poorly understood on the Qinghai-Tibetan Plateau of China. In this study, we therefore combined data of the geography, climate, soil properties, and vegetation characteristics from 319 sites across the plateau to investigate their relationships with the horizontal and vertical patterns of SOC, TN, and TP concentrations and their stoichiometric ratios (C:N and N:P). We observed higher SOC (30.5–46.8 mg g^-1), TN (2.4–3.4 mg g^-1), C:N (14.7–18.0), and N:P (6.9–8.0) in alpine meadows, forests, and shrublands and higher TP (1.6 mg g^-1) in croplands. Overall, SOC, TN, TP, C:N, and N:P showed decreasing trends (by 67%, 64%, 19%, 12%, and 54%, respectively) along the whole soil profile (0–100 cm). Soil cation exchange capacity and bulk density were the stronger environmental drivers of SOC and TN. Soil TP showed latitudinal and longitudinal increasing trends in all soil layers. Soil properties explained most of the variations in SOC (67%–90%), TN (67%–87%), C:N (61%–89%), and N:P (64%–85%), with increasing impacts along the soil profile. Geography and climate influenced soil TP directly and indirectly through their impacts on soil properties, with geography being the predominant driver (46%–65%) along the soil profile. The variation in soil C:N was mostly driven by SOC and TN, and the direct and indirect effects of the environmental factors were relatively weak. Geography, climate, soil properties, and vegetation characteristics indirectly impacted soil N:P through their impacts on TN and TP in all the soil layers. Altogether, our findings illuminate the relative contributions of geography, climate, soil properties, and vegetation characteristics to soil C:N and N:P, thus enhancing our understanding of C, N, and P cycling across the Qinghai-Tibetan Plateau.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 5","pages":"Pages 901-913"},"PeriodicalIF":7.3,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050655","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":"Basal application combined with topdressing and foliar application of silicon and selenium fertilizers reduces soil cadmium and lead bioavailability and their translocation to brown rice","authors":"Jingyi HU ,&nbsp;Ronghao TAO ,&nbsp;Xinyun XIE ,&nbsp;Hongjuan LU ,&nbsp;Xiaojun SHI ,&nbsp;Wenling YE","doi":"10.1016/j.pedsph.2024.06.010","DOIUrl":"10.1016/j.pedsph.2024.06.010","url":null,"abstract":"<div><div>Soil and foliar applications of silicon (Si) and selenium (Se) fertilizers can inhibit the transfer of heavy metals from the soil to crops. However, it remains unclear how Si and Se affect the bioavailability of cadmium (Cd) and lead (Pb) in soil and thereby their transfer to rice in Cd and Pb-polluted fields. In this study, seven treatments were set up in a field experiment conducted in a nonferrous metal mining area in Tongling City, Anhui Province, China: no Si/Se fertilization control (CK), basal Si/Se fertilization (Si-1/Se-1), basal and topdressing Si/Se fertilization (Si-2/Se-2), and basal, topdressing, and foliar Si/Se fertilization (Si-3/Se-3). The results indicated that compared to CK, rice yield increased by 3.94%–14.56% in the other treatments, with the most significant increase observed in Si-3 and Se-3. Additionally, the Cd content in brown rice decreased by 15.42%–51.55%, while Pb content decreased by 16.49%–47.18%. In all treatments except Si-1, both metal contents decreased to below the limits specified in China's food safety standard (GB 2762–2022). Furthermore, they impeded the translocation of these metals to the brown rice, thereby effectively diminishing metal accumulation in rice grain. The effect of Se fertilizer was better than Si fertilizer in decreasing the bioconcentration factors of Cd and Pb and inhibiting their translocation to brown rice. At the same time, the applications of Si and Se increased the Si and Se contents of rice aboveground parts, respectively, and the Se content of brown rice in Se-3 increased by 77.56%, meeting the Se enrichment standard (GB/T 22499–2008). The contents of diethylenetriamine pentaacetic acid-extractable Cd and Pb in soil decreased in all Si/Se treatments by 25.53% and 22.37% in Se-3, respectively. All Si/Se treatments reduced the acid-exchangeable and reducible Cd and Pb in soil and transformed them into the more stable oxidizable and residual fractions. This study revealed that the bioavailability of Cd and Pb in soil and their translocation to brown rice were significantly reduced by the basal application combined with topdressing and foliar application of Si and Se fertilizers.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 4","pages":"Pages 667-677"},"PeriodicalIF":5.2,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144331303","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":"Sustainable remediation of cadmium-contaminated soils: Capture by Fe3O4/polyaniline nanocomposites and removal by magnetic separation","authors":"Xiaochen CHEN ,&nbsp;Fuxiang ZHANG ,&nbsp;Yijia HUANG ,&nbsp;Qian GUAN ,&nbsp;Jianying YU ,&nbsp;Jianyu ZHANG ,&nbsp;Ao WANG ,&nbsp;Yu LIU ,&nbsp;Xiaoyu CUI ,&nbsp;Xianhua LIU ,&nbsp;Junyu ZHU ,&nbsp;Jie CHEN","doi":"10.1016/j.pedsph.2024.06.008","DOIUrl":"10.1016/j.pedsph.2024.06.008","url":null,"abstract":"<div><div>Cadmium (Cd) contamination of soil is a global environmental issue. Traditional remediation techniques such as immobilization, leaching, and phytoextraction have numerous shortcomings, which has led to growing interest in the development of low-cost, high-efficiency, and environmentally friendly agents for removing Cd from soil. In this study, four magnetite (Fe₃O₄)/polyaniline (PANI) nanocomposites, Fe₃O₄(1.0)/PANI, Fe₃O₄(1.5)/PANI, Fe₃O₄(2.0)/PANI, and Fe₃O₄(2.5)/PANI, were developed using 4 mL aniline monomer and 1.0, 1.5, 2.0, and 2.5 g Fe₃O₄, respectively, and used as remediation agents with magnetic separation and regeneration capabilities. The Cd adsorption isotherms showed a better fit to the Langmuir model, with Fe₃O₄(1.5)/PANI exhibiting the highest Cd adsorption capacity of 47.62 mg g^-1 at 25 °C. Then, Fe₃O₄(1.5)/PANI was used to remediate four Cd-contaminated soils typical in China (black, brown, cinnamon, and red), all with a Cd content of 180 mg kg^-1 after spiking. The results showed that the total Cd removal efficiency was satisfactory at 25.25%–38.91% and the exchangeable Cd removal efficiency was 36.03% on average. In addition, soil basic properties did not show significant changes after remediation. Regarding the regeneration performance, a higher total Cd removal efficiency (27.89%–44.96%) was achieved after the first regeneration cycle of Fe₃O₄(1.5)/PANI. After two regeneration cycles, Fe₃O₄(1.5)/PANI exhibited decreased total Cd removal efficiency compared to after the first regeneration, but its efficiency remained above 95% of or higher than those of virgin Fe₃O₄(1.5)/PANI. The synthetic process of Fe₃O₄/PANI was simple and cost-effective, and Fe₃O₄/PANI exhibited a high Cd removal efficiency with easy recovery and recyclability. Therefore, Fe₃O₄/PANI is a promising solution for the sustainable and efficient remediation of Cd-contaminated soils, especially for the reclamation of highly contaminated development land.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 5","pages":"Pages 809-819"},"PeriodicalIF":7.3,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145050673","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":"Compositional and functional succession of soil bacterial communities during long-term rice cultivation on saline-alkali soils: Insights derived from a new perspective on core bacterial taxa","authors":"Yu SUN ,&nbsp;Li JI ,&nbsp;Jingjing CHANG ,&nbsp;Yingxin LI ,&nbsp;Hongbin WANG ,&nbsp;Deliang LU ,&nbsp;Chunjie TIAN","doi":"10.1016/j.pedsph.2024.06.009","DOIUrl":"10.1016/j.pedsph.2024.06.009","url":null,"abstract":"<div><div>The conversion of saline-alkali soils into paddy fields for long-term rice cultivation involves multiple disturbances, and as a result, soil microbial communities are altered to adapt to changing environmental conditions. However, a comprehensive understanding of the succession of soil bacterial communities that occurs during this process is still lacking. In the present study, we utilized data obtained from paddy fields of different rice cultivation years (0–23 years) to investigate the compositional and functional succession of soil bacterial communities. We focused on core bacterial taxa that were specifically enriched at different successional stages. Generalized joint attribute modeling (GJAM) was used to identify core bacterial taxa. Results indicated that the bare saline-alkali soil (0 year, prior to any rice cultivation) shared few core amplicon sequence variants (ASVs) with paddy fields. In the bare saline-alkali soil, Longimicrobiaceae from the phylum Gemmatimonadetes was dominant, while the dominance was subsequently replaced by Burkholderiaceae and Pedosphaeraceae–-phyla affiliated with Proteobacteria and Verrucomicrobia–-after 5 and 23 years of rice cultivation, respectively. The relative abundances of nitrogen metabolism functions in the core bacterial communities of the bare saline-alkali soil were higher than those at other successional stages, while sulfur metabolism functions exhibited the opposite trend. These indicated that the role of the core bacterial taxa in mediating nutrient cycling also evolved and adapted to changing soil conditions as rice cultivation was established. Redundancy analysis (RDA) indicated that the composition of the core bacterial community in paddy fields with rice cultivation for 0, 2 and 4, 6, 8, 10, and 12, and 20 and 23 years were driven by soil nitrate nitrogen content, pH, available phosphorus content, and the ratio of total carbon to total nitrogen, respectively. In summary, the present study provides insights into the succession of soil bacterial communities and core bacterial taxa that occurs during long-term rice cultivation.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 4","pages":"Pages 641-654"},"PeriodicalIF":5.2,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144331201","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":"Insight into slag-enhanced thermal desorption at the organo-mineral interface of clay soils","authors":"Juan ZHANG ,&nbsp;Xin WANG ,&nbsp;Xinyue DU ,&nbsp;Shukai FAN ,&nbsp;Hui LIU ,&nbsp;Minghua ZHANG","doi":"10.1016/j.pedsph.2024.06.005","DOIUrl":"10.1016/j.pedsph.2024.06.005","url":null,"abstract":"<div><div>Multiple active components in steel slags can optimize soil texture and catalyze the thermal desorption of refractory organic pollutants, especially polycyclic aromatic hydrocarbons (PAHs). In this study, a safety and risk assessment was conducted on toxic metals present in collected steel slags, and the refining slag with a high content of free-CaO from the XG iron and steel plant (XGRS) was selected and used to regulate the plasticity index (PI) of clay soils. For the clay soil with high liquid limit and high plasticity (CH), the PI reduced from 34.3% to 24.8% with steel slags at an addition ratio of 10% (mass percent), and for the clay soil with low liquid limit (CL), the PI decreased from 22.8% to 16.5%, resulting in silt soil with optimal thermal properties. The thermal removal efficiency of PAHs in CH decreased from 81.9% to 74.0% at 350°C as the soil water content increased from 0 to 150 g kg⁻¹, due to the hydration and swelling of clay minerals and the heat loss associated with dehydroxylation and dehydration. The efficiency further decreased to 68.7% using 2% (mass percent) CaO as an additive due to the delayed dehydr(oxyl)ation of clay minerals and enhanced aromatization of soil organic matter. In contrast, addition of 2% high-content titania-bearing slag (HTBS) enhanced the removal efficiency of high-ring PAHs, with the efficiency increasing for 5-ring from 52.6% to 59.7% and for 6-ring from 76.6% to 81.8%. This is due to the presence of amorphous TiO₂ and crystalline CaTiO₃ in HTBS, which can degrade water to produce reactive oxygen species. The 2% XGRS addition facilitated the complete removal of PAHs by air-supplemented lattice oxygen, leading to the oxidation of C–C bonds in CH to C–O, C=O, and O–C=O functional groups. This study provides valuable insights into the use of additives to enhance the thermal remediation of PAH-contaminated clay soils <em>via</em> activating oxygen species and oxidizing C–C bonds in organo-mineral complexes within clay soils.</div></div>","PeriodicalId":49709,"journal":{"name":"Pedosphere","volume":"35 2","pages":"Pages 312-324"},"PeriodicalIF":5.2,"publicationDate":"2024-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141395878","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}