1,734 results on '"Nitrogen content"'
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2. Delving into the thermal and energetic properties of the polyvinyl azide along with its compatibility with nitrocellulose
- Author
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Mehelli, Oussama, Abdous, Slimane, Habes, Abdelmalek, Liu, Wenbin, Khadraoui, Azzedine, and Derradji, Mehdi
- Published
- 2025
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- View/download PDF
3. Hydrothermal carbonization coupling with liquid dimethyl ether extraction pretreatment of sewage sludge: Hydrochar performance improvement and low-nitrogen biocrude production
- Author
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Wang, Chenyu, Gui, Biao, Wu, Chaoyue, Sun, Jipeng, Ling, Xiaolong, Zhang, Haoxiang, and Zuo, Xiaojun
- Published
- 2023
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4. Effect of nitrogen content on microstructure and mechanical properties of duplex stainless steels via wire arc additive manufacturing
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Li, Gang, Song, Shuainan, Cai, Qun, Wu, Biao, and Wen, Zhichao
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- 2025
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5. Enhancing soil health with increasing the nitrogen content of zeolite-based fertilizers for agricultural applications.
- Author
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Oguz, Melike and Arslan, Hakan
- Subjects
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NITROGEN in soils , *NITROGEN fertilizers , *FERTILIZER application , *AMMONIUM nitrate , *PLANT nutrients , *ZEOLITES - Abstract
Zeolite-based-fertilizers can be obtained by adsorbing plant nutrients to their porous structure. In this research, the natural zeolite (0–200 μm) from Gordes/Türkiye was combined with NH4NO3 in a 1:4 solid ratio and processed at 200 °C for 2–24 hours and characterized with diffrent techniques. The optimal synthesis time was 8 hours, yielding a fertilizer with 5.06% nitrogen content. The zeolite-based-fertilizer exhibited a clinoptilolite structure similar to the raw zeolite but demonstrated a greater percentage of mass loss in the DTA/TGA analyses and distinct nitrate peaks in the FTIR spectra, attributable to ammonium nitrate adsorption. The BET results showed a decrease in the BET surface area after the adsorption of NH4NO3 onto natural zeolite, with measured values of 34.56 m²/g for natural zeolite and 19.24 m²/g for zeolite-based-fertilizer. The results indicate successful synthesis of a zeolite-based nitrogen fertilizer with potential compatibility with Green Deal goals. [ABSTRACT FROM AUTHOR]
- Published
- 2025
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- View/download PDF
6. Enhancement of nitrogen content in fullerene soot via radical decarboxylative coupling under catalytic and noncatalytic conditions.
- Author
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Hosseini, Fatemeh Sadat and Zamani, Mehdi
- Subjects
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TRANSITION metal catalysts , *FIELD emission electron microscopy , *FOURIER transform infrared spectroscopy , *COUPLING reactions (Chemistry) , *DIFFERENTIAL scanning calorimetry , *X-ray emission spectroscopy - Abstract
Herein, a fast and efficient method for enhancement of nitrogen content in fullerene soot up to 21.44 wt.% via catalytic and noncatalytic radical decarboxylative coupling reactions with 4-nitrobenzoic acid under mild microwave irradiation is developed. The experiments are performed in N-methyl-2-pyrrolidone (NMP) or NMP/H2O solution containing an oxidant among K2S2O8, (NH4)2S2O8, Oxone, KMnO4, MnO2, CrO3, K2Cr2O7, ceric ammonium nitrate (CAN) and 2,2,6,6-tetramethylpiperidinyloxy (TEMPO). The several unimetallic and bimetallic salts of Cu, Ag, Mn, Fe, Ni, Co, Pb, Cr, Pd, Cu/Pd, Ag/Cu, Ag/Pb, Ag/Pd, Cr/Ag and Cr/Pd are examined as catalysts. The morphological and textural features as well as thermal behavior of the prepared samples are studied by X-ray diffraction (XRD), scanning electron microscopy/energy-dispersive X-ray spectroscopy and elemental mapping (SEM/EDS-Map), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and thermogravimetry analysis differential scanning calorimetry (TGA-DSC). XRD patterns for most samples show a predominantly amorphous structure. The highest nitrogen content belongs to the sample prepared by CrO3. The nitrogen content is enhanced by the presence of Ag and Pd salts. Using NMP/H2O as solvent provides higher performance than NMP for enhancement of nitrogen content. The enhancement of nitrogen content reflects the increase of NO2 groups in the texture of fullerene soot detecting by FT-IR and TGA-DSC. The heat released from thermal decomposition of the prepared samples increases when transition metal catalysts are used in the preparation procedure. [ABSTRACT FROM AUTHOR]
- Published
- 2025
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7. SC-ResNeXt: A Regression Prediction Model for Nitrogen Content in Sugarcane Leaves.
- Author
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Lu, Zihao, Sun, Cuimin, Dou, Junyang, He, Biao, Zhou, Muchen, and You, Hui
- Subjects
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MACHINE learning , *DEEP learning , *AGRICULTURAL productivity , *DATA mining , *FERTILIZER application - Abstract
In agricultural production, the nitrogen content of sugarcane is assessed with precision and the economy, which is crucial for balancing fertilizer application, reducing resource waste, and minimizing environmental pollution. As an important economic crop, the productivity of sugarcane is significantly influenced by various environmental factors, especially nitrogen supply. Traditional methods based on manually extracted image features are not only costly but are also limited in accuracy and generalization ability. To address these issues, a novel regression prediction model for estimating the nitrogen content of sugarcane, named SC-ResNeXt (Enhanced with Self-Attention, Spatial Attention, and Channel Attention for ResNeXt), has been proposed in this study. The Self-Attention (SA) mechanism and Convolutional Block Attention Module (CBAM) have been incorporated into the ResNeXt101 model to enhance the model's focus on key image features and its information extraction capability. It was demonstrated that the SC-ResNeXt model achieved a test R2 value of 93.49% in predicting the nitrogen content of sugarcane leaves. After introducing the SA and CBAM attention mechanisms, the prediction accuracy of the model improved by 4.02%. Compared with four classical deep learning algorithms, SC-ResNeXt exhibited superior regression prediction performance. This study utilized images captured by smartphones combined with automatic feature extraction and deep learning technologies, achieving precise and economical predictions of the nitrogen content in sugarcane compared to traditional laboratory chemical analysis methods. This approach offers an affordable technical solution for small farmers to optimize nitrogen management for sugarcane plants, potentially leading to yield improvements. Additionally, it supports the development of more intelligent farming practices by providing precise nitrogen content predictions. [ABSTRACT FROM AUTHOR]
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- 2025
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8. Seedling Growth and Systemic Uptake of Liquid Vermicompost-Coated Seeds in Organic Pumpkin (Cucurbita sp.).
- Author
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Pola, Wissanee and Aiamla-or, Sukanya
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PLANT translocation ,RHODAMINE B ,GUM arabic ,PLANT growth ,CUCURBITA - Abstract
Liquid vermicompost (LVC) is one of the organic ingredients for improving plant growth. This study aims to investigate the impact of the application of LVC coating formulations in distinct ratios on seeding emergence, seedling growth parameters, and nitrogen content as well as the systemic uptake characteristics in seedlings. Coating formulations contained gum arabic (GA) mixed with 5–15% of LVC and were applied to pumpkin seeds and compared to non-coated seeds. All samples were stored under cold and ambient conditions for 3 months to evaluate the performance of the coating. Results showed no statistical distinctions in the percentage of seedling emergence. Nevertheless, the 5LVC-GA in the organic formulation significantly increased shoot length, seedling growth rate (SGR), seedling vigor index (SVI), and nitrogen content (%) in the coated seedlings. Additionally, the evaluation of seedling uptake was achieved using rhodamine B as a fluorescent tracer which was diluted in the organic formulation. This explored the transportation of the treatment within a seedling. Therefore, the application of an optimum concentration of 5LVC-GA treatment can improve seedling growth and nitrogen accumulation. This could be confirmed with fluorescence imaging of translocation to seedling organs. However, seed storability declines over three months, emphasizing the need for better coatings and packaging solutions. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
9. Nitrogen‐containing microporous carbon with specific morphology for non‐metallic catalytic NO oxidation at room temperature: The effect of morphology and nitrogen doping.
- Author
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Guan, Jie, Zhu, Yujie, Wang, Jitong, Cheng, Xiaomin, Ma, Cheng, Ling, Licheng, and Qiao, Wenming
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CARBON nanowires ,CATALYTIC oxidation ,ACTIVATION energy ,TEMPERATURE effect ,GRAPHENE oxide - Abstract
The optimization of the gas diffusion path and surface coordination environment through morphology control can improve the intrinsic activity of the catalyst in NO oxidation reactions. Microporous nanosheets, nanowires, and spheres of carbon were constructed using resorcinol and formaldehyde as carbon sources, melamine as nitrogen source, and graphene oxide or carbon nanowires as structure‐directing agents to reveal the effects of morphology and nitrogen‐doping on NO oxidation activity at room temperature. With the increase of coating thickness, the ultramicroporous structure becomes pronounced and the nitrogen content increases, which contribute to the improvement of steady‐state NO conversion. The 2D microporous nanosheets (TDC‐200) with sheet structure shows prominent diffusion and adsorption capability than 1D nanowires and sphere, which shortens the gas diffusion path and enhances the efficient utilization of ultramicropores, thereby presenting the highest NO oxidation activity of 78.4% at room temperature. The results of DFT calculations further demonstrate that doping of nitrogen atoms could significantly reduce the (2NO + O2)ads energy barrier and accelerate the reaction. This study provides a deeper understanding of the NO oxidation on non‐metallic catalyst. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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10. Insight into the co-hydrothermal humification of corn stalk and sewage sludge for enhanced nitrogen-rich humic acid production.
- Author
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Li, Zhihua, Shao, Yuchao, He, Wenjing, Luo, Zhangrui, Huo, Weizhong, Ye, Rong, and Lu, Wenjing
- Abstract
The high organic carbon content in corn stalks (CS) and the rich nitrogen resources in sewage sludge (SS) render them ideal for the hydrothermal production of nitrogen-enriched hydrothermal humic acid (HHA). This study conducted co-hydrothermal humification experiments using varying ratios of CS to SS under two distinct mixing modes: 1) co-hydrothermal carbonization of CS and SS, followed by alkaline hydrothermal humification to yield HHA, and 2) mixing CS-derived hydrochar with SS, followed by alkaline hydrothermal humification to yield HHA. The results indicated no significant difference in HHA yield between the modes when using equivalent raw material ratios. Importantly, the HHA produced did not pose a heavy metal risk. However, HHA from mode (1) had nearly double the nitrogen content compared to mode (2) and contained more valuable metal elements. The study confirmed that while co-hydrothermal humification of CS and SS did not significantly enhance HHA yield, it did markedly increase nitrogen content. Furthermore, HHA yield decreased with increasing SS content in the raw materials, likely due to SS's high ash content (52.4 wt%). In contrast, the nitrogen content in HHA increased with higher SS content, rising from 2.0 wt% to 3.8 wt% in mode (1) and from 1.1 wt% to 2.3 wt% in mode (2). Upon comprehensive analysis of both modes, the study suggests that mode (1) is more promising for engineering applications, as it facilitates the efficient disposal of a larger amount of SS. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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11. Effects of antimony on the soil enzymes, microbial, and rhizobial activity of legumes.
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Yang, Yiran, Yang, Zaifu, Tian, Xinyue, Xu, Jingyao, and Kan, Simeng
- Subjects
NITROGEN in soils ,MUNG bean ,SOIL enzymology ,SOIL microbiology ,ANTIMONY - Abstract
Leguminous farmland in China is severely polluted by antimony. Here, to explore the effects of antimony stress on rhizobia and soil microorganisms in leguminous plants, mung beans, kidney beans, and peanuts were grown in soil with different concentrations of Sb
3+ , Sb5+ , and Sb3+ +Sb5+ . Antimony had a promotional effect on soil sucrase and catalase activities and an inhibitory effect on urease activity. The effects of Sb3+ on sucrase, catalase, and urease activities were 3.3–11.1, 1.27–1.29, and 1.24–3.05 times those of Sb5+ , respectively. Antimony reduced the rhizobial activity by 20.63–57.84%, with the inhibitory effect positively related to the antimony content. Additionally, the inhibitory effect of Sb3+ was 1.10–2.22 times that of Sb5+ . This inhibition decreased the total nitrogen and ammonia nitrogen content in the soil. However, the decrease in Sb3+ was 0.46–1.54 times that of Sb5+ . Sb3+ significantly altered the microbial activity. [ABSTRACT FROM AUTHOR]- Published
- 2024
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12. Biochar distribution mode in soil affects the vegetative peanut growth, nitrogen uptake and nitrogen-fixing bacteria activity.
- Author
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XIANGZHU WANG, MAN WU, CHENGBIN SUN, MIAO LIU, LIYU YANG, HAIYAN LIANG, QI WU, and PU SHEN
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ROOT-tubercles ,AGRICULTURE ,NUTRIENT uptake ,ROOT development ,NITROGEN-fixing bacteria - Abstract
Biochar plays an important role in agricultural production as it can improve soil fertility, promote nutrient adsorption and enhance plant growth. However, the distribution of biochar in the soil significantly impacts its application effect. In order to investigate the impact of non-uniform biochar distribution on soil nutrient uptake, root shape, peanut development, and the makeup of soil microbial communities, we carried out greenhouse peanut pot studies. This experiment followed a completely randomised design with four treatments, each with three replications. The four treatments were as follows: no biochar application (B0); concentrated biochar application near seeds (B1); relatively concentrated surface application of biochar (B2), and uniformly dispersed application of biochar (B3). The findings demonstrated that, compared to the no-biochar scenario, the aboveground and root nitrogen uptake was significantly (P < 0.05) improved by the B2 treatment, increasing by 42.79% and 51.39%, respectively, compared to the control group. Additionally, it reduced the concentrations of NO
3 - -N and NH4 + -N in the soil. The B2 treatment also significantly (P < 0.05) increased the net photosynthetic rate and aboveground dry matter weight, increasing by 196.85% and 53.96%, respectively, compared to the B0 treatment. The B1 and B3 treatments also demonstrated a higher promoting effect. The growth of the root system and the quantity of root nodules were promoted by the addition of biochar. The number of root nodules in the B2 treatment was 72.22% higher than that in the control group. In terms of microbial and bacterial communities, the addition of biochar increased the number of nitrogen--fixing bacteria to a certain extent, while the relative abundance of soil bacterial communities showed no significant differences. In general, the non-uniform distribution of biochar in the soil significantly affected peanuts' vegetative growth and developmental effects. The relatively concentrated surface application of biochar treatments contributes to improving plant nutrient uptake and root system development. This provides a more effective application method for agricultural personnel to apply biochar fertiliser in the future. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
13. Determination of leaf nitrogen content in apple and jujube by near-infrared spectroscopy
- Author
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Jianping Bao, Mingyang Yu, Jiaxin Li, Guanli Wang, Zhihui Tang, and Jinhu Zhi
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Apple ,Jujube ,Leaf ,Nitrogen content ,Near infrared spectroscopy ,Machine learning ,Medicine ,Science - Abstract
Abstract The nitrogen content of apple leaves and jujube leaves is an important index to judge the growth and development of apple trees and jujube trees to a certain extent. The prediction performance of the two samples was compared between different models for leaf nitrogen content, respectively. The near-infrared absorption spectra of 287 apple leaf samples and 192 jujube leaf samples were collected. After eliminating the outliers by Mahalanobis distance method, the remaining spectral data were processed by six different preprocessing methods. BP neural network (BP), random forest regression (RF), least partial squares (PLS), K-Nearest Neighbor (KNN), and support vector regression (SVR) were compared to establish prediction models of nitrogen content in apple leaves and jujube leaves. The results showed that the determination coefficient (R2), root mean square error (RMSE) and residual prediction deviation (RPD) of the models established by different combined pretreatment methods were compared among the five methods. Compared with the performance of the other four models, the modeling method of SG + SD + CARS + RF was suitable for the prediction of nitrogen content in apple leaves, and its modeling set R2 was 0.85408, RMSE was 0.082188, and RPD was 2.5864. The validation set R2 is 0.75527, RMSE is 0.099028, RPD is 2.1956. The modeling method of FD + CARS + PLS was suitable for the prediction of nitrogen content in jujube leaves. The modeling set R2 was 0.7954, RMSE was 0.14558, and RPD was 2.4264; the validation set R2 is 0.81348, RMSE is 0.089217, and RPD is 2.4552.In the prediction modeling of apple leaf nitrogen content in the characteristic band, the model quality of RF was better than the other four prediction models. The model quality of PLS in predictive modeling of nitrogen content of jujube leaves in characteristic bands is superior to the other four predictive models, These results provide a reference for the use of near-infrared spectroscopy to determine whether apple trees and jujube trees are deficient in nutrients.
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- 2024
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14. Effect of Plant Identity in Wheat Mixtures on English Grain Aphid (Sitobion avenae) Control.
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Tous‐Fandos, Alba, Gallinger, Jannicke, Enting, Arnoud, Chamorro‐Lorenzo, Lourdes, Sans, F. Xavier, and Ninkovic, Velemir
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EMMER wheat , *GREENBUG , *PEST control , *PLANT biomass , *WHEAT , *DURUM wheat ,APHID control - Abstract
ABSTRACT Field experiments have demonstrated that wheat mixtures differ in their ability to regulate aphid populations. To further investigate the effectiveness of wheat mixtures (Triticum aestivum and Triticum turgidum) in controlling aphids, we conducted both laboratory and greenhouse experiments. Specifically, we assessed the associational resistance of two wheat mixtures (Florence‐Aurora with Forment, Florence‐Aurora with Montcada), and their respective monocultures, in different stages of the aphid host selection process. We analysed aphid acceptance rate, population growth, and load under different wheat treatments. Additionally, we characterised wheat aboveground biomass and nitrogen content as important functional traits for aphid resistant. Aphid acceptance decreased in plants of cv. Forment when exposed to volatiles from undamaged Florence‐Aurora plants, whereas the other tested combinations tested had no effect. Aphids performed differently in the two mixtures: Florence‐Aurora mixed with Forment significantly reduced aphid population growth and load compared to the monocultures, whereas the combination of Florence‐Aurora with Montcada wheat had no effect on aphid performance. The plant–plant interactions also modified the analysed traits. Nitrogen content of Florence‐Aurora wheat plants was reduced when mixed with Forment wheat, which may explain the lower aphid load observed in plants of cv. Florence‐Aurora when mixed with plants of cv. Forment. However, mixing wheats with similar aboveground biomass resulted in an increase in the average biomass of plants of both cultivars which could have led to a higher aphid population. The data supports the idea of right neighbour, as the benefits of wheat mixtures for aphid control were determined by the identity of the combined plants (or species). Finally, our results suggest that associating wheats with different traits may promote facilitative interactions, which in turn enhances associational resistance, whereas the combination of wheats with similar traits may result in competitive interactions that may hinder aphid control benefits. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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15. Microstructure and Mechanical Properties of High-Strength Steel 22SiMn2TiB by Pulsed Melt Inert-Gas Welding with Activated Nitrogen Arc.
- Author
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Li, Cong, Xue, Haobo, Zhang, Xiaoyong, Peng, Yong, and Wang, Kehong
- Subjects
STEEL welding ,ELECTRIC welding ,ACTIVE nitrogen ,IMPACT (Mechanics) ,WELDING ,NITROGEN ,HIGH strength steel - Abstract
Strength weakening exists in high-strength steel welds. Most of the researches focus on the composition of welding wire to regulate the weld strength. This article aims to study the role of nitrogen in steel welding by changing the proportion of nitrogen in the protective gas. By adding oxygen, explore the effect of activated nitrogen arc on the weld microstructure and mechanical properties of high-strength steel. Pulsed melt inert-gas welding (PMIG) technology is used to weld high-strength steel, and explore the impact on mechanical properties under activated nitrogen arc conditions. The PMIG welding process is adopted on high-strength steel, and an activated nitrogen arc is formed by Ar + N + O. The results show that under the condition of low heat input, using ER307Mo welding wire, the microstructure of the weld zone is uniform, and the grain is small. With the increase in nitrogen ratio, the actual welding current value decreases, the actual voltage value increases, the nitrogen decomposition reduces the arc energy and the solid nitrogen content of the weld increases. When the nitrogen ratio reaches 30% (vol.%) and O
2 is 2.5% (vol.%), the nitrogen content reaches the maximum value, which is 0.5% (wt.%). The tensile strength reaches 970 MPa. The use of activated nitrogen arc welding can effectively increase the nitrogen content of the weld, promote the solid solution of nitrogen elements, refine the grain, and effectively improve the mechanical properties of the weld of high-strength steel. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
16. Effects of Different Factors on the Composition of Tung Oil Fruit and Tung Cake Meal.
- Author
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WANG Wei, ZHENG Ke, WANG Yue-guang, and JIANG Li-qiang
- Subjects
FRUITCAKE ,TREE age ,GRAVIMETRIC analysis ,MEALS ,HARVESTING time - Abstract
In order to realize its efficient utilization, Vernicia fordii in Qiubei County, Yunnan Province was taken as the research object, and the pickingup time, tree species and age were taken as the research factors, and the gravimetric analysis and composition determination of Tung oil fruit and Tung cake meal were carried out by Kjeldahl method and Soxhlet extraction method. The results showed that the weight of ash and seeds of three-year-old Tung tree picked on October 26 and November 5 was higher than that of millennium tree, and the weight of fruit shell was lower, and the relative weight proportion was 37%:28%:35% at 20 years old. On October 26, the 15-year-old three-year-old Tung cake meal had the highest nitrogen content of 5.04% and 44.63%, respectively, and the crude fat content of Tung cake meal was 14.50%. In conclusion, optimizing the harvest time according to different tree species and tree age can greatly increase the yield and weight of Tung oil fruit, increase the economic value of Tung oleifera, and provide a reference for the efficient utilization and sustainable development of Tung oil fruit and its derivative products. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
17. Effects of Pressure on Nitrogen Content and Solidification Structure during Pressurized Electroslag Remelting Process with Composite Electrode.
- Author
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Suo, Haoyang, Liu, Fubin, Kang, Cong‐Peng, Li, Huabing, Jiang, Zhouhua, and Geng, Xin
- Subjects
- *
ELECTROSLAG process , *LIQUID metals , *METALLIC films , *LIQUID films , *PARTIAL pressure , *FERROSILICON - Abstract
The nitrogen content and solidification structure of the 1Mn18Cr18N ingots produced by the customized laboratory‐scale vacuum induction melting furnace and the pressure electroslag remelting furnace (PESR) with novel composite electrode under different pressure and the same power consumption are compared and studied. The results show that there are perfectly uniform radial chromium and nitrogen profiles during the PESR process. The nitrogen uptake reaction in the PESR process with composite electrode takes place on the liquid metal film on the electrode. Nitrogen uptake could be improved by increasing the nitrogen partial pressure. In addition, the basin depth at a pressure of 0.1 and 1.22 MPa is about 41 and 38 mm, the angle of the grains with respect to the vertical axis is 35° and 31°, respectively. The flat metal basin profile resulted from the thermal resistance at the slag–mold interface decreasing with increasing pressure. Primary and secondary dendritic arm spacing (PDAS and SDAS) variations exhibit an increasing and subsequently decreasing the trend as they move further away from the center in a horizontal direction. Both PDAS and SDAS decrease with increasing pressure from 0.1 to 1.22 MPa. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
18. Nondestructive estimation of specific macroelement contents in thalli of the red macroalga Pyropia yezoensis using hyperspectral imaging.
- Author
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Che, Shuai, Wu, Lan, Wang, Zhen-Dong, Tian, Lin, Du, Guo-Ying, and Mao, Yun-Xiang
- Abstract
In the economically important red macroalga Pyropia, carbohydrates and proteins contents are usually used to evaluate the nutritional status and commercial value. As main component elements of carbohydrates and proteins, C, N and S contents can be the suitable indicators. However, efficient and nondestructive estimation of these elements have not been well established in macroalgae, which is definitely needed in high-throughput phenotyping and selective breeding. In the current study, hyperspectral imaging was used to estimate the C, N and S contents in thalli of Pyropia yesoensis. Based on spectral information acquired by two hyperspectral cameras with range of 400 nm to 1700 nm, two machine learning methods, partial least squares regression (PLSR) and support vector machine regression (SVR), were performed to establish prediction models following different preprocessing methods. The result showed that SVR model following Savitzky-Golay (S-G) smoothing preprocessing performed the best for N content with excellent accuracy (RTest2 = 0.94, RMSE = 0.331, MAPE = 5.47%, RPD = 3.44). Both of PLSR and SVR models could not yet meet satisfactory prediction for C and S content with RTest2 < 0.4 and RPD < 1.5. Further validation on field samples corroborated accuracy and robustness of the optimal estimation model for N. This study demonstrates that hyperspectral imaging is effective for estimating N contents of P.yesoensis thalli. It unveils the capability of hyperspectral imaging with machine learning models for estimating macroelement contents in macroalgae thalli, and offers a convenient, non-destructive, and effective method for the phenotyping and selective breeding of macroalgae. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
19. Determination of leaf nitrogen content in apple and jujube by near-infrared spectroscopy.
- Author
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Bao, Jianping, Yu, Mingyang, Li, Jiaxin, Wang, Guanli, Tang, Zhihui, and Zhi, Jinhu
- Subjects
NEAR infrared spectroscopy ,JUJUBE (Plant) ,ORCHARDS ,STANDARD deviations ,K-nearest neighbor classification - Abstract
The nitrogen content of apple leaves and jujube leaves is an important index to judge the growth and development of apple trees and jujube trees to a certain extent. The prediction performance of the two samples was compared between different models for leaf nitrogen content, respectively. The near-infrared absorption spectra of 287 apple leaf samples and 192 jujube leaf samples were collected. After eliminating the outliers by Mahalanobis distance method, the remaining spectral data were processed by six different preprocessing methods. BP neural network (BP), random forest regression (RF), least partial squares (PLS), K-Nearest Neighbor (KNN), and support vector regression (SVR) were compared to establish prediction models of nitrogen content in apple leaves and jujube leaves. The results showed that the determination coefficient (R
2 ), root mean square error (RMSE) and residual prediction deviation (RPD) of the models established by different combined pretreatment methods were compared among the five methods. Compared with the performance of the other four models, the modeling method of SG + SD + CARS + RF was suitable for the prediction of nitrogen content in apple leaves, and its modeling set R2 was 0.85408, RMSE was 0.082188, and RPD was 2.5864. The validation set R2 is 0.75527, RMSE is 0.099028, RPD is 2.1956. The modeling method of FD + CARS + PLS was suitable for the prediction of nitrogen content in jujube leaves. The modeling set R2 was 0.7954, RMSE was 0.14558, and RPD was 2.4264; the validation set R2 is 0.81348, RMSE is 0.089217, and RPD is 2.4552.In the prediction modeling of apple leaf nitrogen content in the characteristic band, the model quality of RF was better than the other four prediction models. The model quality of PLS in predictive modeling of nitrogen content of jujube leaves in characteristic bands is superior to the other four predictive models, These results provide a reference for the use of near-infrared spectroscopy to determine whether apple trees and jujube trees are deficient in nutrients. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
20. Nitrogen uptake, retranslocation and potential N2-fixation in Scots pine and Norway spruce seedlings.
- Author
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Nilsson, Oscar, Nilsson, Urban, Näsholm, Torgny, Cook, Rachel, and Hjelm, Karin
- Subjects
SCOTS pine ,RED pine ,GROWING season ,SILVER fir ,SEEDLINGS ,NORWAY spruce - Abstract
Scots pine (Pinus sylvestris L.) has higher early growth rates than Norway spruce (Picea abies (L.) H. Karst.). To help efforts to understand possible reasons for this difference and identify appropriate regeneration methods, we labeled seedlings with
15 N in the nursery to probe nitrogen (N) uptake and retranslocation in Scots pine and Norway spruce seedlings at both harsh and fertile sites in southern and northern Sweden. For this,15 N dilution was measured during the first two years after planting. We also examined the potential N2 -fixation capacity in fine roots after 5–7 growing seasons. Use of15 N-labeled seedlings enabled clear discernment of contributions of uptake of new N and retranslocation of old N to new foliage. Scots pine seedlings had higher proportions of N derived from uptake (Ndfu ) than Norway spruce seedlings, and higher growth. Scots pine seedlings were less responsive to site preparation treatments compared to Norway spruce that has a greater need for appropriate silvicultural measures to grow well. After the second growing season, the contribution of N derived from retranslocation (Ndfr ) to N in new foliage had diminished to 10–20% at all except the harshest site, where both species were more dependent on Ndfr . The potential N2 -fixation capacity in fine roots of the two species differed, but in both cases the contribution of N2 -fixation to N-acquisition was negligible. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
21. Ti(C,N) と Cr3C2 を複合添加した超微粒超硬合金の 機械的特性に及ぼす炭素量と窒素量と結合相量の影響.
- Author
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堤 友浩, 髙田 真之, 松原 秀彰, 森 吉弘, and 寺坂 宗太
- Subjects
PARTIAL pressure ,FRACTURE toughness ,NITROGEN ,MICROSTRUCTURE ,CARBIDES - Abstract
WC-Ti(C,N)-Cr
3 C2 -Co ultrafine-grained cemented carbides with different contents of C, N and Co binder phases were fabricated. Their microstructures and mechanical properties were examined, and the relationship between the existing form of Ti(C,N) and various conditions was mainly discussed. The hardness of the samples increased and their fracture toughness decreased with decreasing C content. The average T.R.S. peaked at 4.8 GPa on the low-C side. Their microstructures significantly changed when the N2 partial pressure changed. At a N2 partial pressure of 2.6 kPa, the microstructure became finer and the average T.R.S. was the highest. Meanwhile, at N2 partial pressures of 0 and 11.7 kPa, the microstructure became coarser and the average T.R.S. decreased. As the content of Co binder phase decreased, the number of WC/WC interfaces increased. The average T.R.S. was maximum at 16.4 vol% Co, and decreases with the Co content, but was higher than those of conventional cemented carbides. The existing form of Ti(C,N) changed depending on the N content. Herein, a N2 partial pressure of 2.6 kPa and low C contents were deemed optimal. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
22. Pressure-volume curves of fine roots reveal intraspecific variation across different elevations in a subalpine forest
- Author
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Masumoto, Taiga, Hashimoto, Yuki, Ito, Takumi, Takahashi, Koichi, and Makita, Naoki
- Published
- 2025
- Full Text
- View/download PDF
23. Impact of 50 Hz Electromagnetic Field on the Growth of Chlorella vulgaris.
- Author
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Lingvay, Iosif, Vranceanu-Jipa, Monica, Chihaia, Rares-Andrei, Tókos, Attila, Bartha, Csaba, and Circiumaru, Gabriela
- Subjects
PHOSPHORUS metabolism ,ALGAL growth ,ELECTROMAGNETIC fields ,ANALYTICAL chemistry ,SPECTROPHOTOMETRY - Abstract
The paper presents the experimental study of the influence of a 50 Hz extremely-low-frequency (ELF) electromagnetic field (EMF) on the growth of microalgae Chlorella vulgaris in a BG11 culture medium. Comparative experimental determinations carried out under reference conditions (microalgae growth without exposure to EMF) and with exposure to a homogeneous 50 Hz EMF of various intensities highlighted the fact that EMF has a major impact on both the growth speed and the nitrogen and phosphorus content of the obtained algal mass. Through spectrophotometry and gravimetric determinations, it was found that the lag time was reduced from approximately 8 h (reference) to approximately 6 h for EMF of 2 V/m, 4.5 h for EMF of 5 V/m, 3.2 h for EMF of 10 V/m, and 2.5 h for EMF of 15 V/m. In the stimulation with 15 V/m EMF, the maximum biomass growth rate was 2.75 times higher than the reference, leading to a 2-fold increase in the rate of exhaustion of nutrients, especially phosphorus, in the culture medium. The specific chemical analyses for N-NO
3 , total nitrogen TNb , and total phosphorus Pt highlighted that the N-NO3 content of the culture medium decreased by 58 mg/L/day at 15 V/m EMF compared to 43 mg/L for the reference. The Pt content decreased to 90% depletion after approximately 80 h for the reference culture medium, versus only 48 h of growth with exposure to 15 V/m ELF. The TNb content of the algal suspension in BG11 under the influence of 15 V/m EMF for 96 h of growth increased 14 times compared to the reference. This shows that nitrogen metabolization in the dispersed air was significantly stimulated. It was also found that the 50 Hz EMF also influences the nitrogen and phosphorus content of the increased algal mass. The results show the potential of EMF stimulation of Chlorella vulgaris growth, leading to an increased efficiency of algae growth reactors. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
24. Effect of Differences in Bio-activators and Fermentation Time on the Properties of Liquid Organic Fertilizers Based on Local Rabbit's Urine Waste.
- Author
-
Said, Muhammad Irfan, Mustabi, J., Al Tawaha, Abdel Razzaq, Sirajuddin, Sitti Nurani, Azizah, Nur, and Al-Assaf, Raha
- Subjects
ORGANIC fertilizers ,LIQUID fertilizers ,ORGANIC bases ,FERMENTATION ,PLANT growing media ,URINE - Abstract
Rabbits, which are commonly raised as livestock in many rural areas of Asian countries, produce liquid waste called urine that can have negative environmental impacts. In order to tackle this issue, the development of technology is necessary to effectively process this waste into a form that can be utilized without causing harm to the environment. Urine contains valuable organic compounds that can be used as raw materials for the production of liquid organic fertilizer (LOF). The quality of this fertilizer is dependent on the availability of microorganism substrates and the duration of fermentation. The objective of this study is to investigate the influence of different substrates and fermentation periods on the properties of liquid organic fertilizer. The raw material used in this research is locally sourced rabbit urine. The experiments were conducted in a laboratory at the Faculty of Animal Science, Hasanuddin University, Indonesia. Three types of substrates were employed: bioactivator animal substrate (BAsb), bioactivator plant substrate (BPsb), and commercial microorganism (C-mic) as the control. Two different fermentation periods were tested: 2 weeks and 4 weeks. The data were analyzed using a completely randomized design (CRD) with factorial patterns. The results revealed that the type of bioactivator substrate had a significant impact (p < 0.05) on the N-organic, C/N ratio, P
2 O5 , and K2 O content. However, pH and C-organic showed no significant effect (p > 0.05). Additionally, fermentation time had a significant effect (p < 0.05) on C-organic, N-organic, and the C/N ratio, but pH did not have a significant effect (p > 0.05). Moreover, there was a significant interaction (p < 0.05) between the substrate type and fermentation time in the LOF-RU process. The production of N-organic content from local rabbit urine yielded promising results. For the LOF-RU production process with BAsb or BPsb, fermentation periods of up to 4 weeks can be applied. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
25. Would reducing chlorophyll content result in a higher photosynthesis nitrogen use efficiency in crops?
- Author
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Mao, Linxiong, Song, Qingfeng, Li, Xiaoya, Zheng, Huiqiong, and Zhu, Xin‐Guang
- Subjects
- *
NITROGEN content of plants , *CARBON fixation , *NITROGEN cycle , *RICE , *ANTENNAS (Electronics) - Abstract
Decreasing antenna size is considered a potential option for improving photosynthesis and increasing yield potential. Reducing chlorophyll content has been employed as a strategy to decrease antenna size. One of the commonly mentioned advantages of this approach is its ability to enhance crop nitrogen use efficiency (NUE); however, there is limited field evidence supporting this claim. In this study, we utilized a rice mutant called p35s‐Ami‐YGL1, which exhibits lower chlorophyll content and smaller antenna size, to investigate the effects of modifying leaf chlorophyll content on tissue nitrogen content and NUE. Our results demonstrate that the nitrogen contents in various tissues, including seed tissue, increased on a weight basis in p35s‐Ami‐YGL1 mutants while exhibiting a decrease in C:N ratio. Simultaneously, we observed a reduction in tissue carbon content along with an increase in the levels of chlorophyll precursors such as Proto IX. Specifically, we observed an upregulation in the expression of genes associated with photosynthetic light reactions and chlorophyll metabolism, while there was no increase in the expression of genes involved in the CBB cycle and nitrogen metabolism. In addition, p35s‐Ami‐YGL1 experienced increased photodamage. These findings suggest that the alterations in the C:N ratio and nitrogen content in plants may be attributed to Proto IX‐mediated photodamage and chloroplast reverse transduction signaling. Besides, these results suggest that the observed increase in tissue nitrogen content in p35s‐Ami‐YGL1 does not reflect an increase in plant nitrogen absorption or use efficiency, rather it is a result of stunted carbon fixation capacity. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Optimal Nitrogen Fertilizer Rates for Soybean Cultivation.
- Author
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Wysokinski, Andrzej, Wysokińska, Aleksandra, Noulas, Christos, and Wysokińska, Anna
- Subjects
- *
NITROGEN fertilizers , *ATMOSPHERIC nitrogen , *CROP yields , *NITROGEN in soils , *ROOT-tubercles - Abstract
The soybean (Glycine max. L. Merr) can satisfy a large portion of its requirement for nitrogen (N) by living in symbiosis with symbiotic bacteria. However, this source of N may be inadequate in varieties with high yield potential. To fully exploit this potential, soybeans should additionally utilize mineral forms of nitrogen present in the soil. The aim of this study was to determine the effect of varied nitrogen fertilizer application rates on the dry weight of the separated parts of soybean plants and the whole plant, including the number and weight of root nodules, the potential to reduce atmospheric nitrogen (N2), and the content and uptake of nitrogen. Four levels of pre-sowing nitrogen fertilizer supply were tested: 0, 60, 120, and 180 kg N·ha−1. Measurements of the tested parameters were taken during the flowering stage and the fully ripe stage. During the flowering stage, a reduction in the number of root nodules was observed following the application of 120 and 180 kg N·ha−1. In the fully ripe stage, each increase in nitrogen application caused a systematic decrease in the number of nodules on the roots. Increasing the level of nitrogen application therefore reduced the N2 fixation potential of soybeans, regardless of the developmental stage. The use of high doses of nitrogen in soybean cultivation did not increase seed yield or the weight of the entire plant. With high doses of nitrogen, the content and accumulation of nitrogen in soybean seeds and total mass did not increase. Therefore, the content and yield of crude protein did not increase. The main organ of nitrogen accumulation in the soybean flowering stage was the leaves (58.6–64.8% of total N uptake), however, in the fully ripe stage, it was the seeds (66.8–74.2% of total N uptake). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Adaptation of High-Chromium Refractory Alloy VZh159 (Haynes 282) to Selective Laser Melting.
- Author
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Evgenov, A. G., Shurtakov, S. V., Prager, S. M., and Zaitsev, D. V.
- Subjects
- *
SELECTIVE laser melting , *NICKEL alloys , *CHROMIUM alloys , *HEAT treatment , *SOLID solutions - Abstract
Refractory high-chromium alloy VZh159 (Haynes 282) obtained by the method of selective laser melting (SLM) is studied. C-curves of the precipitation of particles of a topologically closed-packed (tcp) phase are plotted for the temperature range of heat treatment and operation. It is shown that the content of the tcp-particles of unfavorable morphology increases and the ductility of the synthesized material during synthesis in a protective nitrogen environment decreases with increase in the chromium content in the alloy. The intensification of the precipitation of the particles of the tcp-phase is associated with decrease in the solubility of chromium in the solid solution at high temperatures due to elevation of the nitrogen content in the alloy. To stabilize the alloying system, the chromium content in alloy VZh159 is reduced by 1 wt.% with respect to the upper and lower alloying limits as compared to the deformable counterpart, which makes it possible to prevent marked lowering of the ductility of VZh159 fabricatedby SLM. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Seedling Growth and Systemic Uptake of Liquid Vermicompost-Coated Seeds in Organic Pumpkin (Cucurbita sp.)
- Author
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Wissanee Pola and Sukanya Aiamla-or
- Subjects
fluorescent microscopy ,seedling emergence ,nitrogen content ,translocation in plants ,storage conditions ,Plant culture ,SB1-1110 - Abstract
Liquid vermicompost (LVC) is one of the organic ingredients for improving plant growth. This study aims to investigate the impact of the application of LVC coating formulations in distinct ratios on seeding emergence, seedling growth parameters, and nitrogen content as well as the systemic uptake characteristics in seedlings. Coating formulations contained gum arabic (GA) mixed with 5–15% of LVC and were applied to pumpkin seeds and compared to non-coated seeds. All samples were stored under cold and ambient conditions for 3 months to evaluate the performance of the coating. Results showed no statistical distinctions in the percentage of seedling emergence. Nevertheless, the 5LVC-GA in the organic formulation significantly increased shoot length, seedling growth rate (SGR), seedling vigor index (SVI), and nitrogen content (%) in the coated seedlings. Additionally, the evaluation of seedling uptake was achieved using rhodamine B as a fluorescent tracer which was diluted in the organic formulation. This explored the transportation of the treatment within a seedling. Therefore, the application of an optimum concentration of 5LVC-GA treatment can improve seedling growth and nitrogen accumulation. This could be confirmed with fluorescence imaging of translocation to seedling organs. However, seed storability declines over three months, emphasizing the need for better coatings and packaging solutions.
- Published
- 2025
- Full Text
- View/download PDF
29. Nitrogen uptake, retranslocation and potential N2-fixation in Scots pine and Norway spruce seedlings
- Author
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Nilsson, Oscar, Nilsson, Urban, Näsholm, Torgny, Cook, Rachel, and Hjelm, Karin
- Published
- 2024
- Full Text
- View/download PDF
30. Effect of transplanting date and nitrogen levels on quality and nutrient content of bidi tobacco
- Author
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Chudasama, S.D., Gediya, K.M., Chavda, C.P., Ninama, A.R., and Shiyal, V.N.
- Published
- 2023
- Full Text
- View/download PDF
31. Cellulose Nitrates-Blended Composites from Bacterial and Plant-Based Celluloses.
- Author
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Gismatulina, Yulia A. and Budaeva, Vera V.
- Subjects
- *
NITROCELLULOSE , *CELLULOSE , *DICHLOROMETHANE , *SOOT , *SCANNING electron microscopy , *SPECIFIC heat , *NITRIC acid - Abstract
Cellulose nitrates (CNs)-blended composites based on celluloses of bacterial origin (bacterial cellulose (BC)) and plant origin (oat-hull cellulose (OHC)) were synthesized in this study for the first time. Novel CNs-blended composites made of bacterial and plant-based celluloses with different BC-to-OHC mass ratios of 70/30, 50/50, and 30/70 were developed and fully characterized, and two methods were employed to nitrate the initial BC and OHC, and the three cellulose blends: the first method involved the use of sulfuric–nitric mixed acids (MAs), while the second method utilized concentrated nitric acid in the presence of methylene chloride (NA + MC). The CNs obtained using these two nitration methods were found to differ between each other, most notably, in viscosity: the samples nitrated with NA + MC had an extremely high viscosity of 927 mPa·s through to the formation of an immobile transparent acetonogel. Irrespective of the nitration method, the CN from BC (CN BC) was found to exhibit a higher nitrogen content than the CN from OHC (CN OHC), 12.20–12.32% vs. 11.58–11.60%, respectively. For the starting BC itself, all the cellulose blends of the starting celluloses and their CNs were detected using the SEM technique to have a reticulate fiber nanostructure. The cellulose samples and their CNs were detected using the IR spectroscopy to have basic functional groups. TGA/DTA analyses of the starting cellulose samples and the CNs therefrom demonstrated that the synthesized CN samples were of high purity and had high specific heats of decomposition at 6.14–7.13 kJ/g, corroborating their energy density. The CN BC is an excellent component with in-demand energetic performance; in particular, it has a higher nitrogen content while having a stable nanostructure. The CN BC was discovered to have a positive impact on the stability, structure, and energetic characteristics of the composites. The presence of CN OHC can make CNs-blended composites cheaper. These new CNs-blended composites made of bacterial and plant celluloses are much-needed in advanced, high-performance energetic materials. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. 甲烷裂解——中国南方寒武系页岩含气量低的 一个重要原因.
- Author
-
米敬奎, 帅燕华, 姜 林, and 马行陟
- Abstract
Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
- Full Text
- View/download PDF
33. Properties of Forest Tree Branches as an Energy Feedstock in North-Eastern Poland.
- Author
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Stolarski, Mariusz Jerzy, Wojciechowska, Natalia, Seliwiak, Mateusz, and Dobrzański, Tomasz Krzysztof
- Subjects
- *
TREE branches , *SCOTS pine , *NORWAY spruce , *MOISTURE in wood , *WOOD chips , *EUROPEAN larch , *RENEWABLE energy sources - Abstract
Tree branches from forest tree harvesting for the timber industry are an important energy feedstock. Solid biofuel in the form of wood chips, produced from branches, is an excellent renewable energy source for generating heat and electricity. However, the properties of wood chips as a solid biofuel produced from forest tree branches can vary greatly depending on the species from which they have been produced. Therefore, this study aimed to assess the thermophysical properties and elemental composition of fresh branches harvested from nine tree species (pedunculate oak, silver birch, European ash, common aspen, grey alder, Norway maple, Scots pine, European larch and Norway spruce) over three consecutive years (2020–2022). The branches of the tree species most commonly found in Polish forests (Scots pine) were characterized by the highest heating value (an average of 20.74 GJ Mg−1 DM), the highest carbon content (an average of 55.03% DM), the lowest ash (an average of 0.60% DM) and nitrogen contents (an average of 0.32% DM), and low sulfur (an average of 0.017% DM) and chlorine contents (an average of 0.014% DM). A cluster analysis showed that the branches of all three coniferous tree species (Scots pine, Norway spruce and European larch) formed one common cluster, indicating similar properties. The branches of the European ash were characterized by the lowest wood moisture content (an average of 37.19% DM) and thus the highest lower heating value (an average of 10.50 GJ Mg−1). During the three years of the study, the chlorine and ash contents of the branches of the tree species under study exhibited the highest variability. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
34. In Situ Nondestructive Detection of Nitrogen Content in Soybean Leaves Based on Hyperspectral Imaging Technology.
- Author
-
Zhang, Yakun, Guan, Mengxin, Wang, Libo, Cui, Xiahua, Li, Tingting, and Zhang, Fu
- Subjects
- *
LEAF anatomy , *SOYBEAN , *NITROGEN , *GENETIC algorithms , *PREDICTION models ,LEAF growth - Abstract
In this paper, hyperspectral imaging technology, combined with chemometrics methods, was used to detect the nitrogen content of soybean leaves, and to achieve the rapid, non-destructive and in situ detection of the nitrogen content in soybean leaves. Soybean leaves under different fertilization treatments were used as the research object, and the hyperspectral imaging data and the corresponding nitrogen content data of soybean leaves at different growth stages were obtained. Seven spectral preprocessing methods, such as Savitzky–Golay smoothing (SG), first derivative (1-Der), and direct orthogonal signal correction (DOSC), were used to establish the quantitative prediction models for soybean leaf nitrogen content, and the quantitative prediction models of different spectral preprocessing methods for soybean leaf nitrogen content were analyzed and compared. On this basis, successive projections algorithm (SPA), genetic algorithm (GA) and random frog (RF) were employed to select the characteristic wavelengths and compress the spectral data. The results showed the following: (1) The full-spectrum prediction model of soybean leaf nitrogen content based on DOSC pretreatment was the best. (2) The PLS model of soybean leaf nitrogen content based on the five characteristic wavelengths had the best prediction performance. (3) The spatial distribution map of soybean leaf nitrogen content was generated in a pixel manner using the extracted five characteristic wavelengths and the DOSC-RF-PLS model. The nitrogen content level of soybean leaves can be quantified in a simple way; this provides a foundation for rapid in situ non-destructive detection and the spatial distribution difference detection of soybean leaf nitrogen. (4) The overall results illustrated that hyperspectral imaging technology was a powerful tool for the spatial prediction of the nitrogen content in soybean leaves, which provided a new method for the spatial distribution of the soybean nutrient status and the dynamic monitoring of the growth status. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Growth and Nodulation Behavior of Three Leguminous Weeds of Mizoram with Potential Utility as Green Manure Crop.
- Author
-
JOPIR, JYOTI and UPADHYAYA, KALIDAS
- Abstract
Legumes contribute substantially to global crop production and soil nitrogen fertility and play a crucial role in agriculture, agroforestry and the ecosystem due to their ability to fix the atmospheric nitrogen. This study investigated the growth and nodulation behavior of three prevalent leguminous weeds viz., Crotolaria micans, Calopogonium mucunoides and Aeschynomene indica in Mizoram. Seeds of the legume species were collected and pretreated and sown in polybags of 13 X 13 cm in March 2020. Observations on the plant height and biomass; the number and biomass of the nodules on different categories of the roots were carried out three months after sowing. The total number of nodules/plants was in the order A. indica (488.30) > C. micans (21.00) > C. mucunoides (12.10). The shape of their nodules was globose, fan shaped and globose with white streak. Nodule biomass and nitrogen content varied across species, with C. micans demonstrating superior nitrogen content despite fewer numbers of nodules. These findings shed light on leguminous weed growth and nodulation behaviors, facilitating sustainable agricultural practices. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
36. PAN / PI 基多孔碳纤维的制备及 其 CO2 吸附性能研究.
- Author
-
蔡晨阳, 闫圣国, 李瑞劼, 张永刚, and 王雪飞
- Subjects
CARBON fibers ,POLYACRYLONITRILES ,CARBON dioxide adsorption ,ATMOSPHERIC nitrogen ,CHEMICAL structure ,DIMETHYL sulfoxide - Abstract
Copyright of China Synthetic Fiber Industry is the property of Sinopec Baling Petrochemical Company and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
37. Carbon content and other soil properties of near-surface peats before and after peatland restoration.
- Author
-
Hammerich, Jenny, Schulz, Corinna, Probst, Robert, Lüdicke, Thomas, and Luthardt, Vera
- Subjects
PEATLAND restoration ,PEATLANDS ,CARBON in soils ,PEAT ,PEAT mosses ,CARBON cycle - Abstract
Peatland restoration usually aims at restarting the peatlands' function to store carbon within peat. The soil properties of the near-surface peat can give a first understanding of this process. Therefore, we sampled pH value, total organic carbon content (TOC), total nitrogen content (TN), C/N ratio as well as dry bulk density (BD), and describe the structure of near-surface peats in six restored fens in North-East Germany before (2002-2004) and after (2019-2021) restoration. Before restoration, the study sites showed peat degradation to various extents in their near-surface peats. pH values remained relatively stable over time. Comparing the degraded peat horizons, TOC increased significantly in four study sites, ranging from 35.7% to 47.8% in 2002-2004 and from 42.5% to 54.0% in 2019-2021. TN varied from 1.5% to 3.5% in 2002-2004 and from 1.8% to 3.2% in 2019-2021, but changes were only significant in one site, showing a slight decrease. In three sites, the increase in C/N ratio was significant, indicating lower nutrient availability. BD ranged from 0.08 to 0.48 g/cm3 in 2002-2004 and from 0.10 to 0.16 g/cm³ in 2019-2021, decreasing significantly in four sites. The structure of the degraded peat horizons changed after restoration to a more homogenous, sludge mass with larger re-aggregates. In three sites, new peat moss peat layers above the degraded soil horizon were present in 2019-2021, with a mean thickness of 6.8 to 36.1 cm. The structure was comparable to typical, slightly decomposed peat moss peat. Our findings suggest that within about 17 years after fen restoration, and thereby a water table rise close to surface, TOC of the near-surface peats increased to values that are typical for undisturbed peatlands. This indicates that restoration can lead to the re-establishment of peatlands as potential carbon sinks, with TOC within the near-surface peat as one key factor in this process. Further, we assume that the decrease in nutrient availability, decrease of BD, and new, undisturbed peat layers can favor the establishment of mire-specific biodiversity and support ecosystem services similar to near-natural mires. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Persistent effects of swine manure biochar and biogas slurry application on soil nitrogen content and quality of lotus root.
- Author
-
Mengyu Zhang, Jiatao Cui, Meng Mi, Zewen Jin, Ming Hung Wong, Shengdao Shan, and Lifeng Ping
- Subjects
SWINE manure ,NITROGEN in soils ,BIOCHAR ,BIOGAS ,SLURRY - Abstract
Using swine manure biochar and biogas slurry in agriculture proves to be an effective strategy for soil improvement and fertilization. In this study, a pot trial on the growth of lotus root was conducted to investigate the persistent effects of applying 350°C swine manure biochar (1% and 2%) and biogas slurry (50% and 100%) on soil nitrogen nutrient and lotus root quality. The results showed that compared to chemical fertilizer alone (A0B0), swine manure biochar significantly increased soil nitrogen content after one year of application. The contents of total nitrogen (TN), alkali-hydrolyzed nitrogen (AHN), ammonium nitrogen (NH
4 + −N) increased by 17.96% to 20.73%, 14.05% to 64.71%, 17.76% to 48.68% and 2.22% to 8.47%, respectively, during the rooting period. When swine manure biochar was present, the application of biogas slurry further elevated soil nitrogen content. The co-application of swine manure biochar and biogas slurry significantly increased soil nitrogen content, and the 100% nitrogen replacement with biogas slurry combined with 2% swine manure biochar (A2B2) treatment exhibited the most significant enhancement effect during whole plant growth periods. Soil enzyme activities, including soil protease (NPT), leucine aminopeptidase (LAP), b-glucosidase (β-GC) and dehydrogenase (DHA), showed a tendency to increase and then decrease with the prolongation of lotus root fertility period, reaching the maximum value during the rooting period. Compared to A0B0, the treatment with 2% swine manure biochar had the most significant effect on enzyme activities and increased the lotus root’s protein, soluble sugar, and starch contents. Nitrate content decreased with the application of 2% swine manure biochar as the amount of biogas slurry increased. In conclusion, swine manure biochar effectively improved soil nitrogen content, enzyme activity, and lotus root quality. Even after one year of application, 2% swine manure biochar had the best enhancement effect. [ABSTRACT FROM AUTHOR]3− −N) increased by 17.96% to 20.73%, 14.05% to 64.71%, 17.76% to 48.68% and 2.22% to 8.47%, respectively, during the rooting period. When swine manure biochar was present, the application of biogas slurry further elevated soil nitrogen content. The co-application of swine manure biochar and biogas slurry significantly increased soil nitrogen content, and the 100% nitrogen replacement with biogas slurry combined with 2% swine manure biochar (A2B2) treatment exhibited the most significant enhancement effect during whole plant growth periods. Soil enzyme activities, including soil protease (NPT), leucine aminopeptidase (LAP), b-glucosidase (β-GC) and dehydrogenase (DHA), showed a tendency to increase and then decrease with the prolongation of lotus root fertility period, reaching the maximum value during the rooting period. Compared to A0B0, the treatment with 2% swine manure biochar had the most significant effect on enzyme activities and increased the lotus root’s protein, soluble sugar, and starch contents. Nitrate content decreased with the application of 2% swine manure biochar as the amount of biogas slurry increased. In conclusion, swine manure biochar effectively improved soil nitrogen content, enzyme activity, and lotus root quality. Even after one year of application, 2% swine manure biochar had the best enhancement effect. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
39. The Impact of Bacillus coagulans X3 on Available Nitrogen Content, Bacterial Community Composition, and Nitrogen Functional Gene Levels When Composting Cattle Manure.
- Author
-
Liu, Biao, Chen, Wei, Wang, Zhen, Guo, Zhaohui, Li, Yongmei, Xu, Lijuan, Wu, Minxi, and Yin, Hongmei
- Subjects
- *
CATTLE manure , *BACTERIAL communities , *BACILLUS (Bacteria) , *COMPOSTING , *ORGANIC wastes - Abstract
Nitrogen loss is an unavoidable problem during organic waste composting, while exogenous microbial inoculation is a promising strategy for reducing nitrogen loss and improving compost quality. This study was designed to probe available nitrogen levels, bacterial community composition, and the levels of nitrogen functional genes present when composting cattle manure with or without the addition of Bacillus coagulans X3. Bacterial supplementation was associated with the prolongation of the thermophilic stage and improved maturity of the resultant compost. At the maturity stage, samples to which B. coagulans X3 had been added exhibited significant increases in ammonium nitrogen, nitrate nitrogen, and total nitrogen levels. The dominant bacterial phyla observed in these composting samples were Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteriota, and Chloroflexi. B. coagulans X3 addition resulted in significant increases in relative Firmicutes abundance during the thermophilic and cooling stages while also increasing amoA and nosZ gene abundance and reducing nirS gene levels over the course of composting. Together, these data suggest that B. coagulans X3 supplementation provides an effective means of enhancing nitrogen content in the context of cattle manure composting through the regulation of nitrification and denitrification activity. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Characteristics and Changes in the Properties of Cereal and Rapeseed Straw Used as Energy Feedstock.
- Author
-
Stolarski, Mariusz Jerzy, Welenc, Michał, Krzyżaniak, Michał, Olba-Zięty, Ewelina, Stolarski, Jakub, and Wierzbicki, Sławomir
- Subjects
- *
RAPESEED , *STRAW , *CORN straw , *TRITICALE , *ENERGY consumption , *RENEWABLE energy sources , *WHEAT straw , *FEEDSTOCK - Abstract
Solid biofuels, including straw as production residue, are still the largest energy feedstock in the structure of primary energy production from renewable energy sources. However, the properties of straw as a solid biofuel can vary depending on the species from which it was produced and the harvest period and year. Therefore, this study aimed to assess the thermophysical properties and elemental composition of six types of straw (rye, oat, triticale, wheat, corn, and rapeseed straw) obtained over three consecutive years (2020, 2021, 2022). Rye straw had the lowest moisture (mean: 10.55%), ash (mean: 2.71% DM), nitrogen (mean: 0.54% DM) and chlorine (mean: 0.046% DM) contents and the highest carbon content (mean: 47.93% DM), a higher heating value—HHV (mean: 19.03 GJ Mg−1 DM) and a lower heating value—LHV (mean: 15.71 GJ Mg−1). Triticale straw had similar properties, classifying it into the same cluster as rye straw. Corn straw had a remarkably high moisture content (mean: 48.91%), low LHV and high chlorine content. Rapeseed straw contained high levels of Cl, S, N and ash, and they were 643%, 481%, 104% and 169% higher, respectively, than those in rye straw. The sulfur, chlorine and moisture contents of the six straw types under study were highly variable during the three years of the study. Knowledge of the properties of different types of straw as energy feedstocks facilitates the logistics and organization of the supply of bioenergy installations. However, further research is needed, especially studies assessing the energy intensity and logistical costs of different types of straw used for energy purposes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. Effectiveness of Rhizobium tropici sp. Strain UD5 Peat Biofertilizer Inoculant on Growth, Yield, and Nitrogen Concentration of Common Bean.
- Author
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Gatabazi, Auges, Ndhlala, Ashwell Rungano, Mvondo-She, Mireille Asanzi, and Mpai, Semakaleng
- Subjects
MICROBIAL inoculants ,COMMON bean ,RHIZOBIUM ,PEAT ,CLIMATIC classification ,FOOD crops ,CROP yields - Abstract
Common bean (Phaseolus vulgaris L.) ranks among the most produced and consumed legume crops and contains essential macro- and micronutrients. Grain yield of the food crop is markedly decreased by poor management, especially a lack of additional essential nutrient elements through the application of fertilizers. In addition to the application of fertilizers, scholarly research and crop farmers have shown that the use of biofertilizer inoculants improves the yield of legume crops. The objective of this research study was to assess the effectiveness of peat-based Rhizobium tropici sp. UD5 on the growth, yield, and nitrogen concentration of common bean. The peat inoculant contained 6.5 × 10
9 viable cells/g. The experiment was conducted in two climatic zones, as described by the Koppen–Gieger climatic classification system. Treatments involved the peat-based inoculant Rhizobium tropici (T0 = 0 g without inoculation, T1 = 250 g of peat inoculant of strain UD5 for 50 kg seeds, T2 = 500 g of inoculant of strain UD5, and T3 = 200 g of comparative peat inoculant). The results indicated that common-bean-inoculated formulation of R. tropici sp. strain UD5 increased the following parameters compared to the controls: plant height (T1 = 18.22%, T2 = 20.41%, and T3 = 19.93% for bioclimatic zone 1; T1 = 16.78%, T2 = 20.71%, and T3 = 19.93% for bioclimatic zone 2), root length (T1 = 13.26%, T2 = 21.28%, and T3 = 19.38% for zone 1; T1 = 15.06%, T2 = 23.70%, and T3 = 19.20% for zone 2), number of nodules (T1 = 1162.57%, T2 = 1166.36%, and T3 = 1180.30% for zone 1; T1 = 1575%, T2 = 1616.5%, and T3 = 1608.25% for zone 2), size of nodules (T1 = 224.07%, T2 = 224.07%, and T3 = 208.33% for zone 1; T1 = 166.4%, T2 = 180%, and T3 = 140% for zone 2), and yield (T1 = 40.49%, T2 = 47.10%, and T3 = 45.45% for zone 1; T1 = 62.16%, T2 = 54.05%, and T3 = 58.55% for zone 2). R. tropici sp. UD5 peat inoculant formulation also increased the nitrogen concentration in leaves compared to the control (T1 = 3.75%, T2 = 1.12%, and T3 = 8.72%) in both bioclimatic zones. The findings of this study provide significant information on the positive effect of R. tropic UD5 strain peat inoculant application in the improvement of plant growth, development, and yield through the formation of nodules. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
42. Assessing tea plantations biophysical and biochemical characteristics in Northeast India using satellite data.
- Author
-
Mahato, Trinath, Parida, Bikash Ranjan, and Bar, Somnath
- Subjects
TEA plantations ,LEAF area index ,PEARSON correlation (Statistics) ,EVIDENCE gaps ,SPRING - Abstract
Despite advancements in using multi-temporal satellite data to assess long-term changes in Northeast India's tea plantations, a research gap exists in understanding the intricate interplay between biophysical and biochemical characteristics. Further exploration is crucial for precise, sustainable monitoring and management. In this study, satellite-derived vegetation indices and near-proximal sensor data were deployed to deduce various physico-chemical characteristics and to evaluate the health conditions of tea plantations in northeast India. The districts, such as Sonitpur, Jorhat, Sibsagar, Dibrugarh, and Tinsukia in Assam were selected, which are the major contributors to the tea industry in India. The Sentinel-2A (2022) data was processed in the Google Earth Engine (GEE) cloud platform and utilized for analyzing tea plantations biochemical and biophysical properties. Leaf chlorophyll (C
ab ) and nitrogen contents are determined using the Normalized Area Over Reflectance Curve (NAOC) index and flavanol contents, respectively. Biophysical and biochemical parameters of the tea assessed during the spring season (March–April) 2022 revealed that tea plantations located in Tinsukia and Dibrugarh were much healthier than the other districts in Assam which are evident from satellite-derived Enhanced Vegetation Index (EVI), Modified Soil Adjusted Vegetation Index (MSAVI), Leaf Area Index (LAI), and Fraction of Absorbed Photosynthetically Active Radiation (fPAR), including the Cab and nitrogen contents. The Cab of healthy tea plants varied from 25 to 35 µg/cm2 . Pearson correlation among satellite-derived Cab and nitrogen with field measurements showed R2 of 0.61–0.62 (p-value < 0.001). This study offered vital information about land alternations and tea health conditions, which can be crucial for conservation, monitoring, and management practices. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
43. Increasing intraspecific diversity of wheat affects plant nutrient contents but not N recovery in the plant-soil system
- Author
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Thomas Bécu, Sébastien Barot, Jean-Christophe Lata, Xavier Le Roux, Jérôme Enjalbert, and Audrey Niboyet
- Subjects
Agroecology ,Functional diversity ,Intraspecific diversity ,Nitrogen content ,15N recovery ,Plant nutrient content ,Ecology ,QH540-549.5 - Abstract
Crop homogenization in conventional agriculture has been pervasive while ecology has shown positive effects of biodiversity on ecosystem functioning, that arise from complementarity/facilitation and sampling/selection effects. These effects are well documented for interspecific diversity in both natural ecosystems and agroecosystems but remain less documented at an intraspecific level, particularly for the rates of nutrient uptake by plants and nutrient losses from ecosystems. We conducted a field experiment with 88 experimental plots cultivated with 1, 2, 4 or 8 wheat varieties and 1, 2, 3 or 4 functional groups to assess the effects of the number of varietal and functional diversity of winter wheat on plant biomass production, plant nutrient contents (N, Ca, Cu, Fe, Mg, Mn, P, K, Na and Zn) and fertilizer N recovery in the plant-soil system using a 15N labeling method. We found both negative and positive effects of the number of varieties or number of functional groups on shoot Cu, Fe, Zn, Na and P contents, but no significant effects of intraspecific diversity on biomass production, N content and 15N recovery in the plant-soil system. Our results show differential responses to an increase of intraspecific diversity of wheat on the contents of several essential nutrients in plants and highlight the need to jointly analyze multiple nutrients. Our study also suggests that increasing intraspecific diversity had no overall negative effects on biomass production or N content. Using knowledge on variety functional traits to target specific complementarity mechanisms when designing variety mixtures could thus lead to a positive effect on nutrient absorption and biomass production.
- Published
- 2024
- Full Text
- View/download PDF
44. Effectiveness of Rhizobium tropici sp. Strain UD5 Peat Biofertilizer Inoculant on Growth, Yield, and Nitrogen Concentration of Common Bean
- Author
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Auges Gatabazi, Ashwell Rungano Ndhlala, Mireille Asanzi Mvondo-She, and Semakaleng Mpai
- Subjects
rhizobium ,biofertilizer ,growth ,inoculant formulation ,nitrogen content ,peat ,Ecology ,QH540-549.5 - Abstract
Common bean (Phaseolus vulgaris L.) ranks among the most produced and consumed legume crops and contains essential macro- and micronutrients. Grain yield of the food crop is markedly decreased by poor management, especially a lack of additional essential nutrient elements through the application of fertilizers. In addition to the application of fertilizers, scholarly research and crop farmers have shown that the use of biofertilizer inoculants improves the yield of legume crops. The objective of this research study was to assess the effectiveness of peat-based Rhizobium tropici sp. UD5 on the growth, yield, and nitrogen concentration of common bean. The peat inoculant contained 6.5 × 109 viable cells/g. The experiment was conducted in two climatic zones, as described by the Koppen–Gieger climatic classification system. Treatments involved the peat-based inoculant Rhizobium tropici (T0 = 0 g without inoculation, T1 = 250 g of peat inoculant of strain UD5 for 50 kg seeds, T2 = 500 g of inoculant of strain UD5, and T3 = 200 g of comparative peat inoculant). The results indicated that common-bean-inoculated formulation of R. tropici sp. strain UD5 increased the following parameters compared to the controls: plant height (T1 = 18.22%, T2 = 20.41%, and T3 = 19.93% for bioclimatic zone 1; T1 = 16.78%, T2 = 20.71%, and T3 = 19.93% for bioclimatic zone 2), root length (T1 = 13.26%, T2 = 21.28%, and T3 = 19.38% for zone 1; T1 = 15.06%, T2 = 23.70%, and T3 = 19.20% for zone 2), number of nodules (T1 = 1162.57%, T2 = 1166.36%, and T3 = 1180.30% for zone 1; T1 = 1575%, T2 = 1616.5%, and T3 = 1608.25% for zone 2), size of nodules (T1 = 224.07%, T2 = 224.07%, and T3 = 208.33% for zone 1; T1 = 166.4%, T2 = 180%, and T3 = 140% for zone 2), and yield (T1 = 40.49%, T2 = 47.10%, and T3 = 45.45% for zone 1; T1 = 62.16%, T2 = 54.05%, and T3 = 58.55% for zone 2). R. tropici sp. UD5 peat inoculant formulation also increased the nitrogen concentration in leaves compared to the control (T1 = 3.75%, T2 = 1.12%, and T3 = 8.72%) in both bioclimatic zones. The findings of this study provide significant information on the positive effect of R. tropic UD5 strain peat inoculant application in the improvement of plant growth, development, and yield through the formation of nodules.
- Published
- 2024
- Full Text
- View/download PDF
45. Slow-release fertilisers increased microflora and nitrogen use efficiency and thus promoted peanut growth and yield
- Author
-
Cuiping Meng, Man Wu, Xiangzhu Wang, Liyu Yang, Haiyan Liang, Qi Wu, and Pu Shen
- Subjects
photosynthetic characteristics ,root morphology ,nitrogen content ,microbial relative abundance ,oil crop ,Plant culture ,SB1-1110 - Abstract
The effects of large granular slow-controlled release fertiliser prepared by a double coating of sulfur and sodium alginate on peanut growth, nitrogen fertiliser utilisation, and soil microbial community were investigated through peanut pot experiments, with a view to providing a theoretical and practical basis for the development of large granular slow-controlled release fertiliser. The results showed that the homemade large granular fertiliser could promote the root development of peanuts, and the root volume increased by 45.10% compared with the uncoated fertiliser at the fruiting stage. At the same time, the soil NH4+-N and NO3--N content were reduced at the seedling stage and increased at the fruiting stage to achieve the fertiliser's slow and controlled release effect. A significant contribution to the net photosynthetic rate was made for growth development and yield in the middle and late stages. Pod dry weight was significantly higher at the blooming stage than uncoated fertiliser, 4.8% higher at the fruiting stage, and 22.9% higher in nitrogen use efficiency (NUE). In terms of microbial bacterial communities, the large granular slow-release fertiliser promoted the diversity of the treated bacterial communities to some extent, with little difference in the relative abundance of soil bacterial communities. These results showed that a one-time application of homemade large granular slow-release fertiliser positively affected peanuts in terms of yield increase, promotion of nitrogen uptake and improved nitrogen utilisation under nitrogen application with urea equivalent, but the overall effect on soil microbial community was small.
- Published
- 2024
- Full Text
- View/download PDF
46. Factors determining the variability of the size of generative reproduction organs and leaves of Cytisus scoparius (L.) Link in western Poland
- Author
-
Małgorzata Maj and Marian J. Giertych
- Subjects
floral morphology ,leaf area ,fabaceae ,environmental factors ,nitrogen content ,Botany ,QK1-989 - Abstract
Common broom Cytisus scoparius (L.) Link is a native shrub, common both in Europe and Poland and in many other areas of the world, it is considered an invasive plant. e size of the organs of generative reproduction and the factors determining it are still poorly understood. The study of the size of broom flowers, fruits, seeds and leaves was carried out on 16 plots in western Poland. Habitats were described using Ellenberg’s index values, which allowed us to divide the study into two types: warm, rich in nitrogen, and moister with higher pH. It has been shown that a significant part of the variability in the size of flowers and their elements is conditioned by inter-individual differences. Some features (wings and keel area, number of seeds, or nitrogen content in stems) are also dependent on the type of habitat. Probably the key factor influencing the size of generative organs and the number of seeds is the availability of water in the environment. In more moist habitats and with a higher pH, the organs of generative reproduction are larger, and the nitrogen content is lower. The size of individual elements of the perianth is significantly correlated with each other, and the number of seeds depends on the size of the keel. Depending on environmental factors, the size of the generative organs may affect the efficiency of pollination, which in turn determines the size and number of seeds. The ability of C. scoparius to adapt to various edaphic conditions, the ability to establish symbiosis with atmospheric nitrogen-fixing bacteria, and the production of size-diverse flowers that can be pollinated by insects of various sizes determine its invasive success.
- Published
- 2023
- Full Text
- View/download PDF
47. Carbon content and other soil properties of near-surface peats before and after peatland restoration
- Author
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Jenny Hammerich, Corinna Schulz, Robert Probst, Thomas Lüdicke, and Vera Luthardt
- Subjects
Mire ,Rewetting ,pH value ,Nitrogen content ,C/N ratio ,Dry bulk density ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
Peatland restoration usually aims at restarting the peatlands’ function to store carbon within peat. The soil properties of the near-surface peat can give a first understanding of this process. Therefore, we sampled pH value, total organic carbon content (TOC), total nitrogen content (TN), C/N ratio as well as dry bulk density (BD), and describe the structure of near-surface peats in six restored fens in North-East Germany before (2002–2004) and after (2019–2021) restoration. Before restoration, the study sites showed peat degradation to various extents in their near-surface peats. pH values remained relatively stable over time. Comparing the degraded peat horizons, TOC increased significantly in four study sites, ranging from 35.7% to 47.8% in 2002–2004 and from 42.5% to 54.0% in 2019–2021. TN varied from 1.5% to 3.5% in 2002–2004 and from 1.8% to 3.2% in 2019–2021, but changes were only significant in one site, showing a slight decrease. In three sites, the increase in C/N ratio was significant, indicating lower nutrient availability. BD ranged from 0.08 to 0.48 g/cm3 in 2002–2004 and from 0.10 to 0.16 g/cm3 in 2019–2021, decreasing significantly in four sites. The structure of the degraded peat horizons changed after restoration to a more homogenous, sludge mass with larger re-aggregates. In three sites, new peat moss peat layers above the degraded soil horizon were present in 2019–2021, with a mean thickness of 6.8 to 36.1 cm. The structure was comparable to typical, slightly decomposed peat moss peat. Our findings suggest that within about 17 years after fen restoration, and thereby a water table rise close to surface, TOC of the near-surface peats increased to values that are typical for undisturbed peatlands. This indicates that restoration can lead to the re-establishment of peatlands as potential carbon sinks, with TOC within the near-surface peat as one key factor in this process. Further, we assume that the decrease in nutrient availability, decrease of BD, and new, undisturbed peat layers can favor the establishment of mire-specific biodiversity and support ecosystem services similar to near-natural mires.
- Published
- 2024
- Full Text
- View/download PDF
48. Increasing intraspecific diversity of wheat affects plant nutrient contents but not N recovery in the plant-soil system.
- Author
-
Bécu, Thomas, Barot, Sébastien, Lata, Jean-Christophe, Roux, Xavier Le, Enjalbert, Jérôme, and Niboyet, Audrey
- Subjects
PLANT nutrients ,PLANT biomass ,BIOMASS production ,NUTRIENT uptake ,WINTER wheat ,PLANT diversity ,WHEAT - Abstract
• Wheat varietal and functional diversity were manipulated in the field. • Increasing intraspecific diversity of wheat did not influence biomass production. • Increasing intraspecific diversity did not alter
15 N recovery by plants and soil. • Increasing intraspecific diversity affected plant Cu, Fe, Zn, Na and P contents. Crop homogenization in conventional agriculture has been pervasive while ecology has shown positive effects of biodiversity on ecosystem functioning, that arise from complementarity/facilitation and sampling/selection effects. These effects are well documented for interspecific diversity in both natural ecosystems and agroecosystems but remain less documented at an intraspecific level, particularly for the rates of nutrient uptake by plants and nutrient losses from ecosystems. We conducted a field experiment with 88 experimental plots cultivated with 1, 2, 4 or 8 wheat varieties and 1, 2, 3 or 4 functional groups to assess the effects of the number of varietal and functional diversity of winter wheat on plant biomass production, plant nutrient contents (N, Ca, Cu, Fe, Mg, Mn, P, K, Na and Zn) and fertilizer N recovery in the plant-soil system using a15 N labeling method. We found both negative and positive effects of the number of varieties or number of functional groups on shoot Cu, Fe, Zn, Na and P contents, but no significant effects of intraspecific diversity on biomass production, N content and15 N recovery in the plant-soil system. Our results show differential responses to an increase of intraspecific diversity of wheat on the contents of several essential nutrients in plants and highlight the need to jointly analyze multiple nutrients. Our study also suggests that increasing intraspecific diversity had no overall negative effects on biomass production or N content. Using knowledge on variety functional traits to target specific complementarity mechanisms when designing variety mixtures could thus lead to a positive effect on nutrient absorption and biomass production. [Display omitted] [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
49. Inversion Study of Nitrogen Content of Hyperspectral Apple Canopy Leaves Using Optimized Least Squares Support Vector Machine Approach.
- Author
-
Hou, Kaiyao, Bai, Tiecheng, Li, Xu, Shi, Ziyan, and Li, Senwei
- Subjects
SUPPORT vector machines ,FRUIT trees ,LEAST squares ,MULTIPLE scattering (Physics) ,ORCHARD management ,SPECTRAL reflectance ,ORCHARDS - Abstract
The rapid and accurate estimation of the nitrogen content of fruit trees helps to achieve a precise management of orchards. Hyperspectral data were collected from leaves of apple tree canopies at different fertility stages through field experiments to investigate the relationship between the nitrogen content and spectral reflectance of apple canopy leaves. Two different preprocessing methods, Savitzky–Golay (SG) smoothing and multiple scattering correction (MSC), were used to extract the feature bands by combining the successive projection method (SPA) and the competitive adaptive weighting algorithm–partial least squares (CARS-PLS). The reflectance values of the feature bands screened via these two methods were used as inputs to construct the multi-factor inversion models of apple canopy leaf nitrogen content based on the long- and short-term memory (LSTM) network, the support vector regression (SVR) and the Least Squares Support Vector Machine Regression (RIME-LSSVM). The study compared the ability of three algorithmic models to estimate leaf nitrogen content, and the results showed that the model constructed with the reflectance values of the characteristic bands screened by the CARS-PLS algorithm as inputs was more effective in predicting the nitrogen content of leaves. Furthermore, the accuracy of the model constructed using RIME-LSSVM was significantly higher than that of the model constructed using the long- and short-term memory network and support vector regression, in which the coefficient of determination of the test set (R-squared) is 0.964 and the root-mean-squared error (RMSE) is 0.052. Finally, the CARS-PLS algorithm combined with the RIME-LSSVM model has a higher prediction accuracy. The study demonstrated the feasibility and reliability of hyperspectral techniques for the estimation of nitrogen content of apple leaves in the Aksu region. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Stratified diagnosis of cotton canopy spectral characteristics based on CWT-SPA and its relationship with moisture, nitrogen, and SPAD values.
- Author
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Zhang, Nannan, Zhang, Xiao, Shang, Peng, Yuan, XinTao, Li, Li, and Bai, Tiecheng
- Subjects
- *
COTTON , *MOISTURE , *SOIL testing , *WAVELET transforms , *NITROGEN , *PATIENT monitoring - Abstract
Cotton is an economically valuable crop worldwide, and accurate and rapid leaf moisture content, nitrogen content, and soil plant analysis development (SPAD) value estimations are crucial for cotton growth. In this study, high-resolution spectral data were collected for the Tahe 2 cotton variety in Alar City, Xinjiang. The raw spectra were preprocessed using four methods: first derivative, standard normal variate transformation, second derivative, and multiplicative scatter correction. Wavelet coefficients at multiple scales were generated from the raw spectra using a continuous wavelet transform (CWT) and CWT with first derivative (CWT-FD). A quantitative detection model combining CWT and CWT-FD with successive projection algorithm – partial least squares (SPA-PLS) was developed to estimate the leaf moisture content, nitrogen content, and SPAD values. The performances of the different scales and methods for estimating these parameters were compared. Six stratification methods were employed to determine the optimal modelling results and decomposition scales for the parameters under various stratification schemes. The results demonstrated that the CWT and CWT-FD methods significantly improved the accuracy of estimating cotton canopy spectral characteristics related to the parameters, surpassing that of conventional spectral processing methods. The mexh, db5, and db5 wavelet basis functions, along with scale 3, were identified as the optimal modelling choices for moisture content, nitrogen content, and SPAD values throughout the cotton plant growth period. Among the six vertical stratification structures of cotton, the CWT and CWT-FD methods, along with the three wavelet basis functions, achieved the best results for the three parameters in the upper layer. The optimal relative percent deviation values for the three parameters of typical leaves ranged from 1.603 to 2.016, indicating satisfactory modelling performance. These findings provide a theoretical foundation for accurately estimating leaf moisture content, nitrogen content, and SPAD values using spectral technology, enabling the simultaneous extraction and monitoring of multiple physiological indicators. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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