Understanding the effects of external organic and inorganic components on soil fertility and quality is essential for improving low-yielding soils. We conducted a field study over two consecutive ...rice growing seasons to investigate the effect of applying chemical fertilizer (NPK), NPK plus green manure (NPKG), NPK plus pig manure (NPKM), and NPK plus straw (NPKS) on the soil nutrient status, enzyme activities involved in C, N, P, and S cycling, microbial community and rice yields of yellow clayey soil. Results showed that the fertilized treatments significantly improved rice yields over the first three experimental seasons. Compared with the NPK treatment, organic amendments produced more favorable effects on soil productivity. Notably, the NPKM treatment exhibited the highest levels of nutrient availability, microbial biomass carbon (MBC), activities of most enzymes and the microbial community. This resulted in the highest soil quality index (SQI) and rice yield, indicating better soil fertility and quality. Significant differences in enzyme activities and the microbial community were observed among the treatments, and redundancy analysis showed that MBC and available N were the key determinants affecting the soil enzyme activities and microbial community. The SQI score of the non-fertilized control (0.72) was comparable to that of the NPK (0.77), NPKG (0.81) and NPKS (0.79) treatments but significantly lower compared with NPKM (0.85). The significant correlation between rice yield and SQI suggests that SQI can be a useful to quantify soil quality changes caused by different agricultural management practices. The results indicate that application of NPK plus pig manure is the preferred option to enhance SOC accumulation, improve soil fertility and quality, and increase rice yield in yellow clayey soil.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Apple-producing systems on China’s Loess Plateau are overfertilized.•Soil nutrients accumulated and slight acidification occurred in apple orchards.•Apple yield was significantly correlated with ...exchangeable Ca.•The optimal age for maximum apple yield was approximately 17 years.•The most suitable sampling depth to evaluate fertility changes was 0–20 cm.
Data on fertilization and spatial characterization of soil chemical properties are crucial for developing sustainable apple production systems. However, such information at regional scale is scarce. We conducted a survey asking farmers in Luochuan County about their current use of fertilizers, and collected 290 soil samples from 0 to 20 cm and 20–40 cm depths, respectively, to examine the spatial variability of eight chemical properties, and analyze the possible relations between soil quality index (SQI), apple yield, and stand age. Results showed apple orchards were severely overfertilized, with chemical N-P2O5-K2O fertilizers of 1230–795–1080 kg ha−1 yr−1 and organic fertilizers applied at the rates of 74.7 kg N ha−1 yr−1, 66.1 kg P2O5 ha−1 yr−1, and 75.8 kg K2O ha−1 yr−1. With the exception of pH, both coefficient of variation and variogram range showed a moderate to high variability (16.5–77.7%) and spatial dependency (7.10–47.8%) for selected parameters. Distribution maps illustrated that the 0–20 cm soil depth was characterized by typically higher soil nutrient contents compared with that of 20–40 cm depth. Relative to the data observed in the 1980s, the averaged pH values decreased by ~0.20 units across 0–40 cm depth, while soil organic matter, total N, available N, P, K and Zn, and exchangeable Ca (Ex-Ca) increased markedly (26.2–508%) in the 0–20 cm depth, whilst few changes ( 9.84–178%) occurred at 20–40 cm depth. Correlation analysis revealed that Ex-Ca was the unique variable that was significantly (P < 0.05) correlated with apple yield at 0–20 cm depth, suggesting the importance of soil Ex-Ca as an indicator of apple production. The relationship between apple yield and stand age was well described by a parabolic model, with ~17 years as the optimal stand age for producing the maximum apple yield. Notably, the SQI scores had significant relationships with apple yields for 8–13, 14–17 and 18–31-yr-old stands in the 0–20 cm depth, but the relationship was only significant for the 14–17-yr-old stands in the 20–40 cm depth, implying that 0–20 cm is the appropriate sampling depth for evaluating soil quality changes in apple production systems. Overall, long-term fertilization improved soil fertility of apple orchards, which required particular attention with regard to overuse of N, P and K fertilizers. Those results provide an important reference for China and other major apple-producing countries.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Financial fraud cases causing serious damage to the interests of investors are not uncommon. As a result, a wide range of intelligent detection techniques are put forth to support financial ...institutions' decision-making. Currently, existing methods have problems such as poor detection accuracy, slow inference speed, and weak generalization ability. Therefore, we suggest a distributed knowledge distillation architecture for financial fraud detection based on Transformer. Firstly, the multi-attention mechanism is used to give weights to the features, followed by feed-forward neural networks to extract high-level features that include relevant information, and finally neural networks are used to categorize financial fraud. Secondly, for the problem of inconsistent financial data indicators and unbalanced data distribution focused on different industries, a distributed knowledge distillation algorithm is proposed. This algorithm combines the detection knowledge of the multi-teacher network and migrates the knowledge to the student network, which detects the financial data of different industries. The final experimental results show that the proposed method outperforms other methods in terms of F1 score (92.87%), accuracy (98.98%), precision (81.48%), recall (95.45%), and AUC score (96.73%) when compared to the traditional detection methods.
Egypt is the largest nitrogen (N) fertilizer consumer in Africa. However, its nitrogen use efficiency (NUE) is low, and the relationships between both dietary options and the NUE trend with reactive ...N (Nr) release into the environment in Egypt have not yet been studied. In this study, we estimated the changes in the N budget and NUE in Egypt during the past 56 years (1961–2016). We also calculated particular virtual N factors (the average amount of Nr released to the environment during food production per unit of N consumption) for major food items to estimate their N footprints (NF). The total N input to croplands increased from 136 kg N ha−1 y−1 (1961–1970) to 307 kg N ha−1 y−1 (2010–2016), while the total crop N uptake increased from 101 kg N ha−1 y−1 to 136 kg N ha−1 y−1, indicating a decrease of NUE from 71% (1960s) to 44% during 2010–2016. Gaseous N emissions of NH3, N2O, and NO increased from 97, 5.6, and 8.3 Gg N y−1 to 339, 29, and 39 Gg N y−1. The total per capita food NF increased from 15 kg N capita−1 y−1 (1961-1970) to 26 kg N capita−1 y−1 (2010–2016). There was a change in the average per capita food consumption NF and food production NF from the 1960s (3.2 and 11.3 kg capita−1 y−1) to 2010–2016 (5.9 and 20.3 kg N capita−1 y−1). There is a dire need to increase the NUE and decrease the food NF in Egypt to minimize the negative consequences of Nr on the environment.
•The applied rate of nitrogen (N) in Egypt is one of the highest in the world.•The total N input to croplands increased from 136 kg N ha−1 y−1 (1960s) to 307 kg N ha−1 y−1 (2010–2016).•Gaseous N emissions of NH3, N2O, and NO increased from 97, 5.6, and 8.3 Gg N y−1 to 339, 29, and 39 Gg N y−1•Nitrogen use efficiency reduced from 71% in 1960s to 44% during 2010–2016.•N footprint elevated from 14 to 26 kg N capita−1 y−1 over the last five decades.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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•Hollow activated carbon fibers (HACFs) are prepared from biomass waste willow catkins.•The HACFs possess high microporous specific surface area(1067m2g−1) with concentrated pore size ...distribution and rich heteroatom-doped functional groups.•The HACFs-based electrode exhibit excellent electrochemical properties of high specific capacitance, considerable rate capability and high energy density.
In this paper, we prepared three different kinds of hollow activated carbon fibers (HACFs) from willow catkins (WCs), phenolic- and pitch-based hollow fibers, respectively. The morphology, pore structure, surface chemical composition and electrochemical properties of these hollow fibers were studied in parallel. Due to its high-hollow, cost-effective as well as eco-friendly nature, HACFs derived from WCs can be served as excellent electrode materials for electrochemical energy storage devices. Electrochemical measurements illustrate that the WCs derived HACFs exhibit not only high specific capacitance of 333Fg−1 at 0.1Ag−1 but also considerable rate capability with a retention of 62.7% (209Fg−1 at 10Ag−1). Symmetric supercapacitor devices that using WCs derived HACFs as electrodes deliver a maximum energy density of ∼8.8Whkg−1 at power density of 50Wkg−1 and good cycling performance with 95.5% retention over 3000 cycles at 5Ag−1 in 6M KOH aqueous electrolytes.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Data related to the spatial variability of properties of paddy soil is critical for improving rice productivity and designing sustainable farming techniques. However, a systematic assessment focusing ...on the spatial variability of low-yield paddy soil has not been conducted in South China. In this context, 560 soil samples were collected across South China and analyzed for nine common chemical properties. Rice yield data was obtained by surveying farmers during soil sampling. Soil parameters and rice yield varied considerably throughout the study area and their coefficients of variation ranged from 17.3% to 74.2%. Experimental semivariograms were developed and a moderate spatial dependence was observed for all selected parameters. Distribution maps, derived by kriging interpolation, illustrated that these paddy fields were characterized by high concentrations of soil organic matter (SOM), total N (TN), available N (AN) and available Zn (AZn); pH values decreased widely comparing with the data reported by the National Soil Survey, especially in southeast China; the areas with low soil P concentrations (<10mgkg−1) were mainly located in southwest China; cation exchange capacity (CEC), available K (AK) and available Si (ASi) had similar trends in spatial distributions with high concentrations in southeast China and low concentrations in southwest. Notably, paddy fields in southeast China were typically deficient in AK due to their concentrations, all of which are almost less than 100mgkg−1. Correlation analysis revealed that rice yield was significantly positively correlated with pH, CEC, AK and ASi, while negatively correlated with AN and AZn. Low pH, AK, CEC and ASi levels may be the most important constraints limiting rice productivity and fertilizers with N and Zn may be over-used and must be applied appropriately. The soil quality index (SQI) was also calculated using the analyzed chemical properties and a significant correlation was observed between SQI and rice yield, supporting earlier findings that good soil chemical health is essential for optimum sustained crop production. The remarkable variations of SQI and rice yield indicated that the potential for increasing rice productivity is a real prospect. Therefore, regional planning fertilization should pay more attention to the spatial variability of soil chemical properties to avoid economic losses and environmental pollution, and especially to the limited nutrients.
•Geostatistics is a good method to characterize spatial variability of soil attributes.•Distribution maps of rice yield and nine soil chemical properties were produced.•Selected parameters varied considerably throughout the study area.•High levels of SOM, TN and AN were observed in paddy fields of Southern China.•Soil available K showed a serious deficiency in southeast China.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this work, natural graphite flake (NG) and mesophase pitch were used as precursor carbons to prepare the graphite blocks, which were doped with Si and Ti powders. After hot-pressed at 2700
°C, we ...investigated the effect of mean size of NG on properties and microstructure of the graphite blocks. Results showed that both thermal conductivity and flexural strength of the graphite blocks were improved as mean size of NG in raw material increased from 50 to 246
μm. However, a decrease of thermal conductivity was observed when mean size of NG was higher than 246
μm. The density and open porosity were respectively 2.26
g/cm
3 and 5.82% when mean size of NG in raw material was 246
μm. The thermal conductivity was enhanced, however, the flexural strength was reduced as hot-pressing temperature increased from 2300 to 3000
°C. The thermal conductivity and flexural strength of the graphite block were respectively 704
W/m
K and 21.1
MPa when hot-pressing temperature was 3000
°C. Phase analysis demonstrated there were diffraction peaks of graphite, TiC and α-SiC crystals in the graphite block as the hot-pressing temperature was less than 2500
°C. No SiC crystals were evident when the hot-pressing temperature was 2700
°C or above.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Yellow clayey paddy soil is a typical soil with low productivity in southern China. However, a systematic evaluation of soil quality, which is important for improving sustainable land use management ...and increasing crop yields, has not been carried out for yellow clayey paddy soils. This study adopted two indicator selection methods, Total Data Set (TDS) and Minimum Data Set (MDS), to evaluate soil quality of high (HPPS), medium (MPPS) and low (LPPS) productive yellow clayey paddy soils and aimed to identify the factors limiting the rice productivity. Twenty-six soil parameters including physical, chemical and microbiological properties including phospholipid fatty acid analysis, were determined. Most measured soil parameters showed significant differences (P ≤ 0.05) between the different productivity paddy soils. Best values were always observed for many soil properties in HPPS, indicating a better nutrient supply and microbiological activity. Those 15 variables having significant differences were selected for principal component analysis, and arbuscular mycorrhizal fungi (AMF), microbial biomass carbon (MBC), available silicon (ASi), available potassium (AK) and total nitrogen (TN) were retained in the refined MDS. After scoring and weighting the selected indicators, a soil quality index (SQI) was calculated using the Integrated Quality Index equation. Based on the TDS method, the mean SQI scores of HPPS, MPPS and LPPS were 0.79, 0.71 and 0.57, respectively. Similarly, HPPS, MPPS and LPPS showed average SQI scores of 0.82, 0.67 and 0.50, respectively, using the MDS method. A significant correlation was observed between SQI and rice yield considering both TDS and MDS methods. Although the TDS method is more accurate, the MDS method can adequately represent the TDS method (r ² = 0.85). Low levels of AK and TN were considered as the major constraints limiting the rice productivity for LPPS. All soil samples collected were rich in available P, Zn and Si, but deficient in available K, which may be the major constraint for the studied regions.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Albic soil is a typical low-yielding soil in eastern China and increasing its productivity is crucial to national food security. However, research data on soil quality, which is essential to ...improving soil fertility and crop yield, have been limited for these Albic soils. The objectives of this paper were to: (i) establish a minimum data set (MDS) for Albic soil quality, (ii) evaluate soil quality status using a soil quality index (SQI), and (iii) determine the factors liming the crop yield. Based on the mean annual crop yield, Albic soil was divided into three classes with high (HPAS), medium (MPAS), and low (LPAS) productivity. Eighty-three soil samples were collected and analyzed for 26 soil physical, chemical, and biological properties. Principal component analysis (PCA) was conducted with 18 variables having significant differences between HPAS, MPAS, and LPAS. Based on the PCA results, an MDS was established with soil organic matter (SOM), total nitrogen (TN), pH, dehydrogenase, and arbuscular mycorrhizal fungi. The SQI was calculated using the Integrated Quality Index equation, and HPAS, MPAS and LPAS received mean SQI scores of 0.76, 0.62, and 0.50, respectively. The clear discrepancy of SQI scores suggested that there was a large potential of increasing crop yield for MPAS, and especially for LPAS. The significant correlation between the SQI and crop yield indicated the index had high biological significance for Albic soils. Overall, HPAS was characterized by low bulk density, high levels of pH, SOM, TN, enzymatic activities, and microbial activities, whereas LPAS showed conversely. Lower status of pH, SOM, and TN were considered as the major constraints limiting crop productivity for LPAS compared with HPAS. Additionally, our results also showed that all the studied soil samples were rich in available P, Si, and Zn, but deficient for available K. Managers in our study area should pay more attention to the LPAS and particularly to the any special limiting factor.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Fast charging capability is highly desired for new generation lithium-ion batteries used in consumer-grade electronic devices and electric vehicles. However, currently used anodes suffer from ...sluggish ion kinetics due to limited interlayer distance. Herein, the coal-based semicoke was chosen as precursor to prepare cost-effective carbon anodes with high-rate performance through a facile pyrolytic strategy. The evolution of microstructure and its effect on electrochemical performance are entirely studied. The results show that large number of short-ordered defective structures are generated due to the occurrence of turbostatic-like structures when pyrolyzed at 900 °C, which are propitious to large interlayer distance and developed porous structure. High accessible surface area and large interlayer spacing with short-ordered defective domains endow the sample treated at 900 °C under argon (A900) with accelerated ion dynamics and enhanced ion adsorption dominated surface-induced capacitive processes. As a result, A900 delivers high capacity (331.1 mAh g
at 0.1 A g
) and long life expectancy (94.8% after 1000 cycles at 1 A g
) as well as good rate capability (153.2 mAh g
at 5 A g
). This work opens a scalable avenue to fabricating cost-effective, high-rate, and long cycling life carbon anodes.
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