Fertilization has a large impact on the soil microbial communities, which play pivotal roles in soil biogeochemical cycling and ecological processes. While the effects of changes in nutrient ...availability due to fertilization on the soil microbial communities have received considerable attention, specific microbial taxa strongly influenced by long-term organic and inorganic fertilization, their potential effects and associations with soil nutrients remain unclear. Here, we use deep 16S amplicon sequencing to investigate bacterial community characteristics in a fluvo-aquic soil treated for 24 years with inorganic fertilizers and organics (manure and straw)-inorganic fertilizers, and uncover potential links between soil nutrient parameters and specific bacterial taxa. Our results showed that combined organic-inorganic fertilization increased soil organic carbon (SOC) and total nitrogen (TN) contents and altered bacterial community composition, while inorganic fertilization had little impact on soil nutrients and bacterial community composition. SOC and TN emerged as the major determinants of community composition. The abundances of specific taxa, especially
, and an unclassified member of
, were substantially increased by organic-inorganic amendments rather than inorganic amendments only. A co-occurrence based network analysis demonstrated that SOC and TN had strong positive associations with some taxa (
and the members of
subgroup 6,
, and
), and
, and an unclassified member of
were identified as the keystone taxa. These specific taxa identified above are implicated in the decomposition of complex organic matters and soil carbon, nitrogen, and phosphorus transformations. The present work strengthens our current understanding of the soil microbial community structure and functions under long-term fertilization management and provides certain theoretical support for selection of rational fertilization strategies.
A balanced fertilization can increase crop yields partly due to stimulated microbial activities and growths. In this study, we investigated arbuscular mycorrhizal fungi (AMF) in arable soils to ...determine the optimal practices for an effective fertilization. We used pyrosequencing-based approach to study AMF diversity, as well as their responses to different long-term (>20 years) fertilizations, including OM (organic manure) and mix chemical fertilizers of NP (nitrogen–phosphorus), NK (nitrogen–potassium), and NPK (nitrogen–phosphorus-potassium). Results revealed that 124 998 of 18S rRNA gene fragments were dominated by Glomeromycota with 59 611 sequences, generating 70 operational taxonomic units (OTUs), of which the three largest families were Glomeraceae, Gigasporaceae and Acaulosporaceae. In Control and NK plots, AMF diversity and richness significantly decreased under long-term P fertilizations, such as NP, NPK, and OM. Concomitantly, the AMF community structure shifted. Supported by canonical correspondence analysis, we hereby propose that long-term balanced fertilization, especially P fertilizer with additional N fertilizer, helps the build-up of soil nutrients. Consequently, some AMF community constituents are sacrificed, propelled by the self-regulation of plant-AMF-microbes system, resulting in an agro-ecosystem with a better sustainability. This knowledge would be valuable toward better understandings of AMF community in agro-ecosystem, and long-term ecosystem benefits of the balanced fertilization.
This paper was primarily devoted to understand the interactions of soil aggregates, organic carbon (C) and carbon cycle enzymes in aggregates under different fertilization managements, aiming to ...identify the effects of organic and inorganic fertilizer amendments on soil organic C accumulation and the activities of carbon cycle enzymes within aggregates in Vertisol.
A Vertisol soil following 4-year compost and inorganic fertilizer amendments, i.e. no fertilizer (CK), mineral fertilizer (FR) and 60% compost N plus 40% fertilizer N (FRM), was collected to identify the dynamics of organic C, enzymes activities and their associations with macroaggregation using aggregate fractionation techniques.
The organic C content in all FR and FRM treatments was 8.24-41.15% higher than that in CK. An increased amounts of carbon cycle enzymes in aggregates or 0-20 cm bulk soil were also observed in FRM plots. Compared to FR, FRM significantly strengthened the structural stability of macroaggregates and the intimate connection between enzyme activities and macroaggregates.
As a recommended measure, supplementation with organic manure such as compost strengthened the process of mutual promotion between carbon cycle enzymes and macroaggregates, and the synergistic effect would be highly beneficial to soil organic C sequestration.
Artificial intelligence (AI) coupled with promising machine learning (ML) techniques well known from computer science is broadly affecting many aspects of various fields including science and ...technology, industry, and even our day-to-day life. The ML techniques have been developed to analyze high-throughput data with a view to obtaining useful insights, categorizing, predicting, and making evidence-based decisions in novel ways, which will promote the growth of novel applications and fuel the sustainable booming of AI. This paper undertakes a comprehensive survey on the development and application of AI in different aspects of fundamental sciences, including information science, mathematics, medical science, materials science, geoscience, life science, physics, and chemistry. The challenges that each discipline of science meets, and the potentials of AI techniques to handle these challenges, are discussed in detail. Moreover, we shed light on new research trends entailing the integration of AI into each scientific discipline. The aim of this paper is to provide a broad research guideline on fundamental sciences with potential infusion of AI, to help motivate researchers to deeply understand the state-of-the-art applications of AI-based fundamental sciences, and thereby to help promote the continuous development of these fundamental sciences.
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•“Can machines think?” The goal of artificial intelligence (AI) is to enable machines to mimic human thoughts and behaviors, including learning, reasoning, predicting, and so on.•“Can AI do fundamental research?” AI coupled with machine learning techniques is impacting a wide range of fundamental sciences, including mathematics, medical science, physics, etc.•“How does AI accelerate fundamental research?” New research and applications are emerging rapidly with the support by AI infrastructure, including data storage, computing power, AI algorithms, and frameworks.
This paper was primarily devoted to reveal the stock of soil organic carbon (C) as well as its lability and to compare their differences existing among tillage and residue practices, aiming to ...identify the effects on the accumulation process of organic C and its association with macroaggregation. Arable soils following 8-year contrasting managements were collected to determine aggregate size distribution, organic C content and its lability. A wet-sieving method was used to fractionate aggregate fractions including >2000μm large macroaggregates, 2000–250μm small macroaggregates, 250–53μm microaggregates, and <53μm silt+clay fractions. The C amount in physical subfractions was measured using aggregate fractionation techniques. It was found that reduced/no-tillage and straw returning significantly promoted soil macroaggregation and aggregate stability at the 0–10cm depth. The organic C stock was 20.7% higher in 0–5cm soil and 7.5% higher in 5–10cm soil under reduced/no-tillage than continual tillage, whereas straw returning significantly increased organic C stock by 28.8%, 25.1% and 7.7%, respectively at the 0–5, 5–10 and 10–20cm depths. Macroaggregates made a larger contribution to soil organic C accumulation than did other fractions. Both reduced/no-tillage and straw returning significantly increased the contribution of macroaggregates at the expense of microaggregates and silt+clay fractions at the 0–10cm depth. When large and small macroaggregates were further separated into physical subfractions, reduced/no-tillage coupling with straw returning averagely increased the C amount in the intra-particulate organic matter (iPOM) and mineral-associated C (mSOC), but decreased the oxidation stability coefficients (Kos) of organic C in aggregates. Significant and negative relationships were found between the mass proportion of macroaggregates as well as aggregate stability and the Kos values of organic C. The Kos values of macroaggregate-associated C were also significantly negatively correlated with the C amount in subfractions. Overall, the accumulation of organic C in physical subfractions within macroaggregates might contribute to sequester relatively labile organic C in soil following reduced/no-tillage and straw returning, which in turn promoted soil macroaggregation.
•Conservation tillage promotes soil macroaggregation and organic C stock.•The accumulated C is assigned to the relatively labile organic C.•Soil macroaggregation is closely related to the relatively labile organic C.•Organic C lability in macroaggregates is affected by C accumulation in subfractions.
Here, a novel fluorescent sensing strategy is established for the detection of captopril (CP) sensitively on the basis of a nanocomposite of gold nanoclusters (AuNCs) and metal−organic framework ...(AuNCs@ZIF-8). The aggregation-induced emission (AIE) effect will be triggered when AuNCs is encapsulated by metal−organic framework (MOF) which served as a carrier since it limits the molecular motion of AuNCs, and the fluorescence of AuNCs greatly enhanced about 5-time after forming the nanocomposites of AuNCs@ZIF-8. The strong orange-emission at 562 nm was quenched in the presence of mercury ions through dynamic quenching. After adding captopril, the quenched fluorescence of AuNCs@ZIF-8/Hg2+ system would be restored due to the specific interaction among captopril with mercury ions. Simultaneously, the restored degree of AuNCs@ZIF-8/Hg2+ fluorescence depended on the concentration of captopril. Hence, with AuNCs@ZIF-8 serving as reporter signal, the captopril content can be monitored by an “on-off-on” fluorescence sensing mode with a linear relationship of 1–100 μM, and the limit of detection for captopril was 0.134 μM.
In this work, the fluorescence intensity of AuNCs@ZIF-8 nanoprobe could be greatly reduced benefiting from the strong affinity between AuNCs@ZIF-8 and Hg2+, and restored with the addition of captopril. Therefore, an “on-off-on” fluorescence sensing platform based on AuNCs@ZIF-8 nanocomposite was fabricated for the purpose of determining captopril. Display omitted
•A simple and rapid in-situ synthesis strategy for preparing AuNCs@ZIF-8 nanocomposite was developed.•The fluorescence of AuNCs@ZIF-8 was about 5-time stronger than that of AuNCs and possessed stable fluorescence.•The AuNCs@ZIF-8-based sensing platform for captopril detection was realized via “on-off-on” fluorescence sensing mode.•The sensing strategy displayed wider linear range and excellent application prospects.
Knowledge of the structural features of humic substances (HSs) is essential for elucidating the mechanisms of humification in different soil environments and realizing their profound roles in ...environmental issues. The aim of this work was to investigate the chemical structures of fulvic acid (FA), humic acid (HA) and humin (HM) fractions isolated from an upland soil (Fluvisol) and a paddy soil (Anthrosol) typical in China using advanced solid-state 13C nuclear magnetic resonance (NMR) techniques. The results revealed that there were great structural differences of HSs between the two soils. The two FAs showed distinct quantitative differences in aliphatics with more polysaccharides in the FA from the upland soil than from the paddy soil. The HM from the upland soil differed from the paddy soil HM in having more proteins/peptides (23% vs 20%), total aromatics (21% vs 12%) as well as fewer lipids (24% vs 35%) and polysaccharides (27% vs 31%). The HM fractions represented the most different components of organic matter between the two soils. The degree of difference between the two HAs fell in between that of FAs and HM fractions. In particular, the HA from the upland soil had relatively greater degree of aromaticity. Our study indicated that the upland soil exhibited a higher degree of humification compared with the paddy soil. Among the three humic fractions, the FAs featured COO/N-CO groups, and the HAs were more enriched in protonated aromatic C for both soils. In contrast, the two HM fractions contained more O-alkyl C and fewer aromatics than did the other humic fractions, being closer to the original organic materials in soils. We speculate that the evolutionary route of HSs is likely to be the transformation of original organic materials into HM, followed by increased degradation, further oxidization and conversion into HA, and then into FA.
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•Advanced 13C NMR techniques allow the detailed characterization of FA, HA and HM.•The upland soil contained more humified SOM than did the paddy soil.•The two FAs showed distinct quantitative differences in aliphatics.•HM fraction represented the most different component of HSs between the two soils.•The degree of oxidation decreased with a shift from FA, HA to HM.
Taking hydraulic punching test of Zhaozhuang Mine as engineering background, by comparing the field application effects of different hydraulic punching processes, the relationship between coal ...moisture content around the borehole blockage and gas extraction effect was monitored and analyzed. The following conclusions were drawn: the occurrence of borehole blockage was the result of the comprehensive action of coal slag particle size and slag discharge capacity of punching return water. Blocking the borehole led to the accumulation of a large amount of punching high-pressure water and coal slag in the borehole, which compressed and infiltrated the surrounding coal body and reduced gas extraction efficiency of borehole. Under the condition of the same amount of coal produced by punching, the different punching methods led to the great difference in the influence radius of punching. The large flow three-stage coal-breaking hydraulic punching system developed according to the borehole blockage mechanism can effectively reduce the particle size of coal slag, increase the punching flow, effectively avoid borehole blockage, and improve gas extraction efficiency of borehole.
Abstract
Plant‐ and microbially derived carbon (C) are the two major sources of soil organic matter (SOM), and their ratio impacts SOM composition, accumulation, stability, and turnover. The ...contributions of and the key factors defining the plant and microbial C in SOM along the soil profile are not well known. By leveraging nuclear magnetic resonance spectroscopy and biomarker analysis, we analyzed the plant and microbial C in three soil types using regional‐scale sampling and combined these results with a meta‐analysis. Topsoil (0–40 cm) was rich in carbohydrates and lignin (38%–50%), whereas subsoil (40–100 cm) contained more proteins and lipids (26%–60%). The proportion of plant C increases, while microbial C decreases with SOM content. The decrease rate of the ratio of the microbially derived C to plant‐derived C (C
M:P
) with SOM content was 23%–30% faster in the topsoil than in the subsoil in the regional study and meta‐analysis. The topsoil had high potential to stabilize plant‐derived C through intensive microbial transformations and microbial necromass formation. Plant C input and mean annual soil temperature were the main factors defining C
M:P
in topsoil, whereas the fungi‐to‐bacteria ratio and clay content were the main factors influencing subsoil C
M:P
. Combining a regional study and meta‐analysis, we highlighted the contribution of plant litter to microbial necromass to organic matter up to 1‐m soil depth and elucidated the main factors regulating their long‐term preservation.
•Soil pH determines fertilization strategy and fungal community response.•Long-term inorganic fertilization can achieve high crop yield in alkaline soils.•Acidic soil productivity can be maintained ...by inorganic-organic fertilization.•Mortierella and Pseudaleuria were enriched by inorganic-organic fertilization.
Agricultural fertilization plays a crucial role in crop production, and the fungal communities catalyze transformation of soil nutrients in support of crop production. However, it remains controversial about the optimal strategy for fertilizer inputs and the adaptive mechanisms of fungal communities across China. By using seven long-term field fertilization experiments in China, we analyzed crop yields, soil properties and fungal communities in soils that were treated for > 25 years with no fertilizer (control), inorganic fertilizers (NPK) and organic-inorganic fertilizers (NPKM). Long-term NPK resulted in significant acidification up to a decline by 1.20 pH units, while NPKM prevented acidification and increased pH up to 6.39 in three acidic soils with pH < 5.70. NPKM increased crop yields by 1.19–8.72 folds in acidic soils, being significantly higher than NPK. Specific saprotroph Mortierella and Pseudaleuria in acidic soils were exclusively enriched by NPKM. Soil pH was directly related to the abundance of Mortierella, and the enrichment of Mortierella species further caused a positive direct effect on crop yield. In four alkaline soils with pH > 8.11, both NPK and NPKM led to only marginal decline of soil pH, and NPK and NPKM showed comparable crop yields. Some members of Ascomycota in alkaline soils were both enriched by NPKM and NPK. Soil available P and C:N ratio, rather than pH, directly or indirectly affect crop yield in alkaline soils. High crop yield can be achieved by the sole use of inorganic fertilizers in alkaline soils, but acidic soil productivity should be maintained by organic amendment to counteract acidification by inorganic fertilization. Our study advances a mechanistic understanding for optimizing fertilization strategies towards sustainable agriculture under increasingly intensified fertilizer inputs.
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