bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Optimal Oil Filling Control Strategy of Wet Clutch in Agricultural Machinery
Authors: Qian Yu , Wang Lin , Cheng Zhun , Zhao Yirong , Wang Xingwei , Lu Zhixiong
Published: October 2022

To improve the wet clutch engagement quality, which is widely used in agricultural machinery, the oil filling control strategy of a wet clutch is studied based on the method of simulation and experiment in detail in this paper. Firstly, this paper carries out the dynamic analysis of the wet clutch engagement process, establishes the mathematical model of the mechanical domain and the hydraulic domain of the hydraulic execution system, and designs the backstepping oil pressure controller. The controllability of the output oil pressure of the clutch hydraulic actuator is verified on the joint simulation platform of Matlab/Simulink (Version R2017b, MathWorks, Natick, MA, USA) and AMESim (Version 2019.1, Simcenter Amesim, Siemens Digital Industries Softwares, Berlin&Munuch, Germany). Then, this paper analyzes the clutch engagement process, extracts five factors affecting the oil filling process, and selects four clutch engagement quality evaluation indexes. An amount of 50 groups of experiments are carried out on the wet clutch oil filling test simulation platform built by SimulationX (Version 3.8, ESI ITI GmbH, Dresden, Germany). The response surface method (RSM) and stepwise regression analysis method are used to explore the mathematical models of the quality evaluation index and influencing factors of the oil filling process. Through 15 groups of random tests, the prediction accuracy of the stepwise regression model and the RSM model of each index is compared, and the models with high accuracy are selected to establish the comprehensive prediction mathematical model of clutch engagement quality, combined with the variance weight method. Finally, according to the working condition of the 3 MPa oil filling pressure studied in this paper, the optimal oil filling control strategy is obtained by the proposed clutch engagement quality prediction model. Under the target condition, when the oil filling rate of stage 1 is the highest and the proportion of phase 1’s duration to the total oil filling time is 69.65%, the oil filling rate of stage 2 is the lowest and the proportion of phase 2’s duration to the total oil filling time is 21.85%, and the proportion of phase 3’s duration to the total oil filling time is 8.51%, the engagement quality of wet clutch is the best. The research method of wet clutch optimal oil filling control strategy proposed in this paper provides a reliable method for the ride comfort research of agricultural machinery and clutch control.
Some Reflections on the Role of the Eco-Schools Program in the Promotion of Sustainable HEIs: A Case Study in Portugal
Authors: Sousa Sara
Published: October 2022

Currently, the Eco-Schools program plays a key role in the application of the concepts of environmental education and management in the daily life of schools. This program is considered the largest environmental education program for schools of different levels in the world and continues to grow with the constant and ambitious mission to improve literacy and change environmental behaviors, particularly among the youngest who are now students, but will be the future decision-makers, politicians, managers, teachers, and parents. Thus, it is essential to involve this younger generation in the construction not only of a school, but also of a more sustainable community. This research study presents a set of reflections on the main guidelines of the Eco-Schools program, focusing on its methodology and areas of activity. It also analyzes the reality in Portugal, a country where the Eco-Schools program has been developed since 1996 by the European Blue Flag Association (ABAE), an association that works in the three components of sustainability (environmental, economic, and social), reinforcing the importance of educating and involving all the individuals of the community in joint actions for a more sustainable society. The case study consists of a Portuguese Higher Education Institution (HEI) awarded the Green Flag since the year it enrolled in the program, 2018/19. A description, analysis, and reflections are made on some of the main measures implemented in the last academic year within the scope of the Eco-Schools program, noting that, despite some implementation difficulties, the program was successfully developed, involving the participation of students, teachers, staff, and outside school community members, thus contributing to a more sustainable society.
Experimental Investigation into the Effect of Fin Shapes on Heat Dissipation Performance of Phase Change Heat Sink
Authors: Liu Xu , Zhu Keyong , Wei Yijie , Chen Ziwei , Ge Mingming , Huang Yong
Published: October 2022

In this paper, the thermal management of missile-borne components in a flight state is studied. Avoiding excessive component temperatures under the high-temperature circumstances brought by aerodynamic heat is a requirement to guarantee the equipment’s safe and reliable operation. In this work, we designed four finned shell constructions for a phase change module using the phase change temperature control method and then studied their effects on the module’s ability to dissipate heat using an experimental approach. Three sizes of 30 mm, 40 mm, and 50 mm heating pads were used to replicate heat sources with various heat flux densities and heat dissipation regions, with reference to the heating characteristics of various chips. The results demonstrated that the square-shaped fin had the best heat dissipation effect after operating for 10 min under the power of 10 W and 20 W, while the strip-shaped fins exhibited the highest performance under the power of 30 W. The square-shaped fins had the best heat dissipation effect when reducing working time to 5 min. This paper proposes the optimal fin scheme under different power densities, as well as an enhanced heat dissipation idea for the melting process of the phase change materials based on the test results.
Numerical Optimization of Electromagnetic Performance and Aerodynamic Performance for Subsonic S-Duct Intake
Authors: Wang Bin , Wang Qiang
Published: October 2022

In order to improve the performance of subsonic unmanned aerial vehicle (UAV), a knapsack S-duct intake has been designed. The influences of an S-bend diffuser on aerodynamic performance and electromagnetic performance were analyzed firstly. The viscous flow field has been simulated by solving Favre averaged Navier–Stokes equations using a shear stress transport (SST) k-ω turbulence model. The surface current has been simulated by solving Maxwell equations using a multi-level fast multipole method (MLFMM). The multi-objective optimization of the S-duct intake was studied by using the diffuser as the optimized object. The parametric expression of the diffuser model was realized using the fourth order function geometric representation technique. The efficient model based on the Kriging model and non-dominated sorting genetic algorithm-Ⅱ (NSGA-Ⅱ) were used to accelerate the optimization progress. By analyzing the results of an optimal intake chosen from the Pareto front, the total pressure distortion (TPD) index DC60 has decreased by 0.24 at the designed Mach number of 0.9, and the average Radar Cross Section (RCS) has decreased by 2db at the frequency of 3GHz. The optimized S-duct intake could have both excellent aerodynamic performance and electromagnetic performance at various complex conditions.
Analysis of NO Formation and Entropy Generation in a Reactive Flow
Authors: Mohammadi Milad , Abedinejad Mohammad Sadegh
Published: October 2022

A comprehensive investigation of turbulent combustion is accomplished to study the relationship between nitrogen oxide (NO) formation and entropy generation distribution in a non-premixed propane combustion. The radiation heat transfer and combustion are simulated, employing the discrete ordinates model and laminar flamelet model, respectively. A post processing model is employed to estimate the NO formation rate. The present results of NO species formation, mean temperature and velocity are compared with the existing experimental data, and good agreements are obtained. It is shown that the main region of total entropy generation rate and NO formation rate is at the same axial position. The entropy generation distribution may be defined as an index by which the combustion region and main region of NO formation are predicted. However, total entropy generation rate is more sensitive to high temperature (1500–1930 K) than that of NO formation rate. With an increase of 28.7% in temperature, the entropy generation and NO formation rates rise by 900% and 127%, respectively. The occurrence of chemical reactions plays the major role in the generation of entropy.
Numerical and Experimental Study of Nose for LOx Floating Ring Seal in Turbopump
Authors: Bae Joon-Hwan , Kwak Hyun-Duck , Heo Sung-Jae , Choi Chang-Ho , Choi Jong-Soo
Published: October 2022

Floating ring seals are widely used as a leakage control solution for turbomachines because they effectively operate with small clearances between the shaft and seal. The oxidizer pump of the 7 tonf liquid engine in the Korea Space Launch Vehicle II (KSLV-II) operates at high rotational speeds and under cryogenic conditions and has floating ring seals in the bearing cooling path to reduce leakages. In this study, we evaluated the frictional force acting on the nose of the floating ring in the oxidizer pump of the 7 tonf turbopump using numerical analysis, and we investigated the radial force on the floating ring induced by the vibration of the rotor and the flow characteristics around the floating ring seal. Through a comparison of the frictional and floating forces according to the change in the diameter of the floating ring noses, we also estimated the dynamic positioning of the floating ring. In addition, we examined the leakage of the floating ring seals with the rotational speed and gap size of the floating ring, and we used the results as data for designing a floating ring seal. Finally, we performed turbopump real-propellant tests with the floating ring seal of the high and the middle noses, finding that the test result was in good agreement with the results of numerical analysis.
Roughness Effect on the Flow Past Axisymmetric Bodies at High Incidence
Authors: Jiménez-Varona José , Liaño Gabriel , Castillo José L. , García-Ybarra Pedro L.
Published: October 2022

The flow at low Mach numbers and high angles of attack over axisymmetric configurations is not symmetric. The mechanism that triggers the asymmetry is a combination of a global (temporal) instability and a convective (spatial) instability. This latter instability is caused by roughness and other geometrical imperfections, which lead to roll angle dependent forces. The flow at these conditions has a complex vortex sheet structure, with two or three different flow regions. An accurate simulation by means of Computational Flow Dynamics (CFD) is thus very challenging, and many researchers have therefore employed Large Eddy Simulation (LES) codes. This study demonstrates that Unsteady Reynolds Averaged Navier-Stokes (URANS) methods are a suitable alternative, if Scale Adaptive Simulation (SAS) is used. This method is capable of capturing the main flow features, provided that fine meshes, which achieve geometrical similarity between the meshed geometry and the real object, and small-time steps are used. It is also demonstrated that, by using URANS methods in combination with SAS, strong differences in the global and local forces depending on the surface roughness of the model are obtained, a result which coincides with several wind tunnel tests.
Receding Horizon Trajectory Generation of Stratospheric Airship in Low-Altitude Return Phase
Authors: Jing Yuhao , Wu Yang , Tang Jiwei , Zhou Pingfang , Duan Dengping
Published: October 2022

The contribution of this paper is the proposal of a new receding horizon trajectory generation method for stratospheric airships’ return phase. Since the energy consumption, wind field and path constraints are restrictions during the return phase of airships at low altitude, it is crucial to develop novel trajectory optimization methods to ensure that the airship returns to the landing site. In this article, optimization objects and conditions of the return trajectory were constructed, considering the energy consumption and wind field. Then, a modified interior point method (MIP) was used to transform the inequality constraint, which is a simple and adaptable method used to improve the solving efficiency on the basis of a modified multiple shooting method (MMS). In addition, an adaptive gradient descent regulator was improved to reduce the influence on the optimization result due to different selections of the initial search point, and the convergence was made faster and more stable. Finally, considering the performance and path constraints of the airship, the effectiveness of the scheme was verified by numerical experiments under wind effects and a comparison of different methods.
Optimal Circle-to-Ellipse Orbit Transfer for Sun-Facing E-Sail
Authors: Quarta Alessandro A. , Mengali Giovanni , Bassetto Marco , Niccolai Lorenzo
Published: October 2022

The transfer between two coplanar Keplerian orbits of a spacecraft with a continuous-thrust propulsion system is a classical problem of astrodynamics, in which a numerical procedure is usually employed to find the transfer trajectory that optimizes (i.e., maximizes or minimizes) a given performance index such as, for example, the delivered payload mass, the propellant mass, the total flight time, or a suitable combination of them. In the last decade, this class of problem has been thoroughly analyzed in the context of heliocentric mission scenarios of a spacecraft equipped with an Electric Solar Wind Sail as primary propulsion system. The aim of this paper is to further extend the existing related literature by analyzing the optimal transfer of an Electric Solar Wind Sail-based spacecraft with a Sun-facing attitude, a particular configuration in which the sail nominal plane is perpendicular to the Sun-spacecraft (i.e., radial) direction, so that the propulsion system is able to produce its maximum propulsive acceleration magnitude. The problem consists in transferring the spacecraft, which initially traces a heliocentric circular orbit, into an elliptic coplanar orbit of given eccentricity with a minimum-time trajectory. Using a classical indirect approach for trajectory optimization, the paper shows that a simplified version of the optimal control problem can be obtained by enforcing the typical transfer constraints. The numerical simulations show that the proposed approach is able to quantify the transfer performance in a parametric and general form, with a simple and efficient algorithm.
Modeling and Simulation of Flight Profile and Power Spectrum for Near-Space Solar-Powered UAV
Authors: Zhang Liang , Ma Dongli , Yang Muqing , Yang Xiaopeng , Yu Yayun
Published: October 2022

Currently, several solar-powered unmanned aerial vehicles (UAVs) have achieved 24 h uninterrupted cruise. However, models that can cruise for weeks or even months without interruption are in the minority. The technological progress requires the improvement of subsystems and also depends on the accurate planning of flight profile and power spectrum in a long working cycle. Combined with the test data obtained during the development of a solar-powered UAV, this paper establishes systematic mathematical and physical models of aerodynamic, energy, and propulsion systems, which can reflect the change in performance parameters with flight conditions and the performance attenuation with time. Further, a track control strategy based on the principle of maximum energy utilization is proposed, and the energy balance model of each flight stage is established. On the basis of the strategy, the typical flight profile and power spectrum of a solar-powered UAV are analyzed. Finally, the input parameters are decomposed into task parameters (takeoff time window, flight season, flight latitude, takeoff weight) and performance parameters (lift–drag ratio, secondary battery density), and their effects on mission feasibility are studied respectively. The research methods and conclusions of this paper have reference significance for the mission and track planning of solar-powered UAVs.
Response of Rice Yield and Grain Quality to Combined Nitrogen Application Rate and Planting Density in Saline Area
Authors: Chen Yinglong , Liu Yang , Dong Shiqi , Liu Juge , Wang Yang , Hussain Shahid , Wei Huanhe , Huo Zhongyang , Xu Ke , Dai Qigen
Published: October 2022

To determine the combining effects of nitrogen application rate and planting density on rice yield and grain quality formation under salinity conditions, a field experiment was conducted in the coastal saline area using Oryza sativa L. cv. Nangeng 9108 from 2019 to 2020. The experiment was designed with six nitrogen rates (0, 210, 255, 300, 345, and 390 kg ha−1; denoted as N0-N390, respectively) and two transplanting densities (334,000 and 278,000 hills ha−1; denoted as D1 and D2, respectively). The results indicated that, with the increase of nitrogen input rate, the panicles number and spikelets per panicle increased first, subsequently decreased, and peaked under 300 kg ha−1 N, whereas the filled-kernel rate and grain weight displayed a decreasing trend. The panicle number and grain weight were higher under D1 treatment compared to those under D2 treatment, while the spikelet number per panicle and the filled-kernel rate displayed an opposite trend. The grain yield displayed highest under N300D1 treatment among all treatments, accompanied by the highest agronomic N use efficiency, and the actual yield reached 8060.4 kg ha−1 and 7869.8 kg ha−1 in 2019 and 2020, respectively. Increased nitrogen application rate significantly improved the grain processing quality and nutritional quality, while reducing the appearance quality and cooking/eating quality. Higher transplant density was conductive to grain nutritional quality, but notably reduced the processing quality, appearance quality and cooking/eating quality. Overall, a combination of 300 kg ha−1 nitrogen rate and 334,000 hills ha−1 planting density was recommended for relatively higher rice yield and better grain quality in the saline area.
The Design of a Mechanized Onion Transplanter for Bangladesh with Functional Testing
Authors: Stubbs Spencer , Colton Jonathan
Published: October 2022

Rising labor costs and the inefficient manual methods of cultivating red onions in Bangladesh contribute to the country’s failure to meet is own demand. Mechanizing the process of transplanting red onion seedlings will reduce the manual labor required while increasing crop yields. This paper provides an initial study of a proposed mechanized onion transplanter designed to attach to the back side of a two-wheel tractor with power tiller operated-seeder, commonly used in Bangladesh. Testing of a prototype made from these designs proves that the design is functional but requires further development for commercial/widespread use.
Experimental Research on the Physical and Mechanical Properties of the Tussah Cocoon for Leaf-Stripping Machine Development
Authors: Zhao Yongcai , Liu Yuanhang , Li Fade , Li Xisheng , Du Zhanjun , Guo Tiankai , Yan Yinfa , Lu Yao , Song Zhanhua
Published: October 2022

The physical parameters and mechanical properties of the tussah cocoon are of vital importance for the design of a tussah cocoon leaf stripper. In this paper, the freshly harvested tussah cocoons wrapped with fresh leaves (TCFL) and the plucked and dried tussah cocoons (TCDL) were taken as research objects. The physical parameters and mechanical properties of the tussah cocoon with wrapped leaves, leafless tussah cocoons, tussah cocoon shells, tussah pupae, cocoon handle, and oak leaves were measured. The experiment showed that firstly, the radial deformation of the cocoon shell of the tussah cocoon should be controlled to be within 1.05 mm and the axial deformation to be within 1.6 mm. The pressure on the fresh leaf cocoon shell and the dry leaf cocoon shell cannot exceed 14.54 ± 3.16 N and 32.43 ± 7.04 N, respectively. Secondly, when the oak leaves are peeled off, the tensile force on the fresh leaves and dry leaves should be greater than 5.05 ± 3.63 N and 3.35 ± 1.85 N, respectively. Finally, the cocoon stalk can have a negative impact on the leaf-stripping process. These results can provide theoretical support for the design of a tussah leaf stripper to avoid damaging the cocoon shell and tussah pupa during the leaf stripping process.
Live Weight Prediction of Cattle Based on Deep Regression of RGB-D Images
Authors: Ruchay Alexey , Kober Vitaly , Dorofeev Konstantin , Kolpakov Vladimir , Gladkov Alexey , Guo Hao
Published: October 2022

Predicting the live weight of cattle helps us monitor the health of animals, conduct genetic selection, and determine the optimal timing of slaughter. On large farms, accurate and expensive industrial scales are used to measure live weight. However, a promising alternative is to estimate live weight using morphometric measurements of livestock and then apply regression equations relating such measurements to live weight. Manual measurements on animals using a tape measure are time-consuming and stressful for the animals. Therefore, computer vision technologies are now increasingly used for non-contact morphometric measurements. The paper proposes a new model for predicting live weight based on augmenting three-dimensional clouds in the form of flat projections and image regression with deep learning. It is shown that on real datasets, the accuracy of weight measurement using the proposed model reaches 91.6%. We also discuss the potential applicability of the proposed approach to animal husbandry.
Properties of Humic Substances in Composts Comprised of Different Organic Source Material
Authors: Lanno Marge , Klavins Maris , Purmalis Oskars , Shanskiy Merrit , Kisand Anu , Kriipsalu Mait
Published: October 2022

Reusing organic waste as fertilizer is one method to reduce the use of mineral fertilizers and minimize waste disposal in landfills. Regulations have been enacted for the processing of organic waste and for recycling end products, but the humic content of organic fertilizers has been neglected. We studied seven composts with different organic input materials and technologies. Humic substances (HSs) were detected in all composts. The total organic carbon in the HSs constituted 8.7 ± 0.1% (SD)–27.0 ± 0.2% of the compost dry matter. Spectral differences between the studied samples in FTIR spectroscopy could be observed at 1700–1000 cm−1, indicating differences in compost precursor material. The EEM peak, associated with humic acids (HAs), was high in composts containing animal by-products (e.g., fish waste, horse manure, and kitchen biowaste). Kitchen biowaste, also when processed by Hermetia illucens larvae and vermicompost, exhibited slower organic material transformation with low humic acid/fulvic acid ratios (<1.60). The results show the importance of source material origin and amendments, which influence the composting process and final products. Our study emphasizes the role of humic substances in the comprehensive evaluation of composts. To maximize the added value of composts, marketing strategies should consider determining the share of humic substances besides the content of organic matter and nutrients.
The Impact of Organizational Support, Environmental Health Literacy on Farmers’ Willingness to Participate in Rural Living Environment Improvement in China: Exploratory Analysis Based on a PLS-SEM Model
Authors: Wang Jing , Ding Xiang , Li Dongjian , Li Shiping
Published: October 2022

The active participation of farmers is not only a real demand to alleviate the dilemma of “free-rider” in improving the rural living environment but also a requirement of the Times to realize ecological sustainability and rural revitalization. The planning behavior theory tells us that improving farmers’ willingness is an important prerequisite for farmers’ activities. This paper constructs the analysis framework of “organizational support (government and village committee) → environmental health literacy → farmers’ willingness” from the actual practice of government-led rural living environment improvement. Using data from a sample of 1225 farmers in Gansu Province and Jiangsu Province, China, we empirically tested the mechanisms of organizational support on farmers’ willingness to participate in living environment improvement and the mediating effect of environmental health literacy using formative structural equation modeling. The study showed that organizational support positively affected farmers’ willingness to participate, the effect of emotional support was more potent than that of instrumental support, and there were regional differences in the relative effects of government support and village committee support on farmers’ willingness to participate. All four types of organizational support positively affected environmental health literacy, but the degree of the effect differed and showed regional heterogeneity. Among the direct effects of farmers’ environmental health literacy on their willingness to participate, basic skills made the highest contribution, followed by basic ideas and the lowest basic knowledge. Among the indirect effects, basic skills made the most significant contribution in the pathway of organizational support to increase farmers’ willingness to participate through fostering farmers’ environmental health literacy. The results can provide a theoretical basis for government and village committees to policy optimization and improve the system, improve the resource utilization of the government and village committees, improve farmers’ environmental health literacy, and change farmers’ participation attitude.
Deep-Learning Approach for Fusarium Head Blight Detection in Wheat Seeds Using Low-Cost Imaging Technology
Authors: Bernardes Rodrigo Cupertino , De Medeiros André , da Silva Laercio , Cantoni Leo , Martins Gustavo Ferreira , Mastrangelo Thiago , Novikov Arthur , Mastrangelo Clíssia Barboza
Published: October 2022

Modern techniques that enable high-precision and rapid identification/elimination of wheat seeds infected by Fusarium head blight (FHB) can help to prevent human and animal health risks while improving agricultural sustainability. Robust pattern-recognition methods, such as deep learning, can achieve higher precision in detecting infected seeds using more accessible solutions, such as ordinary RGB cameras. This study used different deep-learning approaches based on RGB images, combining hyperparameter optimization, and fine-tuning strategies with different pretrained convolutional neural networks (convnets) to discriminate wheat seeds of the TBIO Toruk cultivar infected by FHB. The models achieved an accuracy of 97% using a low-complexity design architecture with hyperparameter optimization and 99% accuracy in detecting FHB in seeds. These findings suggest the potential of low-cost imaging technology and deep-learning models for the accurate classification of wheat seeds infected by FHB. However, FHB symptoms are genotype-dependent, and therefore the accuracy of the detection method may vary depending on phenotypic variations among wheat cultivars.
Consensual Regression of Lasso-Sparse PLS models for Near-Infrared Spectra of Food
Authors: Yuan Lei-Ming , Yang Xiaofeng , Fu Xueping , Yang Jiao , Chen Xi , Huang Guangzao , Chen Xiaojing , Li Limin , Shi Wen
Published: October 2022

In some cases, near-infrared spectra (NIRS) make the prediction of quantitative models unreliable, and the choice of a suitable number of latent variables (LVs) for partial least square (PLS) is difficult. In this case, a strategy of fusing member models with important information is gradually becoming valued in recent research. In this work, a series of PLS regression models were developed with an increasing number of LVs as member models. Then, the least absolute shrinkage and selection operator (Lasso) was employed as the model’s selection access to sparse uninformative ones among these PLS member models. Deviation weighted fusion (DW-F), partial least squares regression coefficient fusion (PLS-F), and ridge regression coefficient fusion (RR-F) were comparatively used further to fuse the above sparsed member models, respectively. Three spectral datasets, including six attributes in NIR data of corn, apple, and marzipan, respectively, were applied in order to validate the feasibility of this fusion algorithm. Six fusion models of the above attributes performed better than the general optimal PLS model, with a noticeable enhancement of root mean errors squared of prediction (RMSEP) arriving at its highest at 80%. It also reduced more than half of the spectral bands; the DW-F especially showed its excellent fusing capacity and obtained the best performance. Results show that the preferred strategy of DW-F model combined with Lasso selection can make full use of spectral information, and significantly improve the prediction accuracy of fusion models.
Phenology Based Variability of Tissue Nutrient Content in Mature Muscadine Vines (Vitis rotundifolia cv. Carlos)
Authors: Freedman Kyle Austin , Rana Tekan Singh , Hoffmann Mark
Published: October 2022

Muscadine (Vitis rotundifolia) is a grape species that is native to the Southeastern US, where several cultivars are grown commercially for processing or direct consumption. Phenology based tissue analysis to determine the nutritional status of a vine is a critical tool for growers to understand fertilizer demands in a vineyard. For European-style wine grapes, tissue sampling for nutrient content is well researched. However, current tissue sampling recommendations for muscadines are solely based on anecdotal knowledge. It is currently unknown if the type of tissue collected has an impact on variability and content of nutrients. Questions also remain as to whether or not seasonal vine phenology impacts tissue nutrient content. Without this knowledge it is difficult for a muscadine grower to make informed decisions on the nutritional status of a muscadine vine. Therefore, we investigated the impact of the phenological vine stage (bloom, fruit set, véraison) on nutrient content in two different tissue types (mature leaf vs. petiole), sampled at two different positions on a muscadine vine (opposite of cluster vs. shoot). The study was conducted over two growing seasons (2019 and 2020) in a commercial mature muscadine vineyard (‘Carlos’). Our results show that over both study years, the highest variability in nutrient content was found during bloom (May–June), while nutrient variability was lower during fruit-set and veraison. We also found fully mature leaf samples showed a lower variability in nutrient tissue content. Based on our results, sampling fully mature leafs from shoots remains the best practice. However, our results also indicate that tissue sampling later in the season might be a better practice, compared to the current practice of taking samples during June.
Anthocyanins in Dairy Cow Nutrition: A Review
Authors: Tian Xingzhou , Lu Qi
Published: October 2022

Oxidative stress is a condition in dairy cows characterized by an imbalance of prooxidants and antioxidants, abnormally high levels of free radicals, or a decline in antioxidant defense mechanisms. Moreover, dairy cows are more inclined to oxidative stress status, which causes damage to the body and DNA damage resulting in a decline in antioxidant potential. Anthocyanins are effective antioxidants and free radical scavengers derived from fruit, purple corn, and other purple plants in nature. Many studies have shown that anthocyanins have favorable antioxidation effects in dairy cows and prevent lipid oxidation to improve milk quality. Accordingly, in the present paper, we mainly review (1) the definition of anthocyanins and the possible absorption and metabolic pathways; (2) the effect of anthocyanins on rumen fermentation parameters and methane production; (3) the mechanism by which anthocyanins enhance antioxidant potential and alleviate oxidative stress by scavenging free radicals and regulating signalling pathways; and (4) the effect of anthocyanins on milk production and milk lipid oxidation in dairy cows. This paper may provide an important rationale for the modulation of dairy cow health and productivity by anthocyanins in the future.
The Effect of Agronomic Management on Micronutrients of Vegetables Grown by Smallholders in Free State and KwaZulu-Natal Provinces of South Africa
Authors: Chitja Joyce , Botha Cobus J. , Siwela Muthulisi , Mudau Fhatuwani Nixwell
Published: October 2022

The production of nutritious food amongst rural farmers has been a challenge for m Cany years. Challenges can be attributed to many factors, including poor access to water, use of old planting methods, financial challenges, etc. Therefore, new climate-smart technologies (CSTs) were introduced to the farmers. The CSTs implemented in the study were in-field rainwater harvesting (IRWH) techniques compared with conventional production (CON). These technologies were applied in combination with sound agronomic management practices, such as mulching and fertilizer application, to produce cabbage, beetroot, spinach and orange-fleshed sweet potato. The vegetables produced were harvested and their nutritional composition analysed to assess whether or not agronomic treatments, water-use technology and season affected their micronutrient levels, with a particular focus on provitamin A and mineral levels. The main finding of the study was that the nutrient levels of the vegetables can be enhanced by adopting IRWH technology combined with different agronomic treatments, especially including mulching as one of the treatment combinations. Limitations: Farmer research participants did not always adhere to research agreements, particularly regarding reserving vegetable samples for analyses. As a result, some experiment replicates are missing. Value: The study findings are of socio-economic significance as they demonstrate that rural, small-scale farmers can apply local, accessible and appropriate agronomic treatments and water-use technologies to achieve economically viable yields of nutritive vegetables to enhance food and nutrition security and household livelihoods of the farmers.
In-Season Wheat Yield Forecasting at High Resolution Using Regional Climate Model and Crop Model
Authors: Kirthiga S. M. , Patel N. R.
Published: October 2022

In-season crop production forecasts at the regional or sub-regional scale are essential to aid in food security through early warning of harvest shortfall/surplus, tailoring crop management decisions and addressing climatic shock. Considering the efforts to establish a framework towards quantifying the crop yield prediction at regional scales are limited, we investigated the utility of combining crop model with the regional weather prediction model to forecast winter wheat yields over space. The exercise was performed for various lead-times in the regions of Punjab and Haryana for the years 2008–2009. A numerical weather prediction (NWP) model was used to generate micro-meteorological variables at different lead times (1-week, 2-weeks, 3-weeks and 5-weeks) ahead of crop harvest and used within the CERES-Wheat crop simulation model gridded framework at a spatial resolution of 10 km. Various scenarios of the yield forecasts were verified with district-wide reported yield values. Average deviations of −12 to 3% from the actual district-wise wheat yields were observed across the lead times. The 3-weeks-ahead yield forecasts yielded a maximum agreement index of 0.86 with a root mean squared error (RMSE) of 327.75 kg/ha and a relative deviation of −5.35%. The critical crop growth stages were found to be highly sensitive to the errors in the weather forecast, and thus made a huge impact on the predicted crop yields. The 5-weeks-ahead weather forecasts generated anomalous meteorological data during flowering and grain-filling crop growth stages, and thus had the highest negative impact on the simulated yields. The agreement index of the 5-week-ahead forecasts was 0.41 with an RMSE of 415.15 kg ha−1 and relative deviation of −2.77 ± 5.01. The proposed methodology showed significant forecast skill for extended space and time scale crop yield forecasting, offering scope for further research and practical applicability.
Assessing the Importance of Natural Regulating Mechanisms in Weed Management: The Case of Weed Seed Predation in a Winter Wheat Field and in Adjacent Semi-Natural Habitat in Northern Hungary
Authors: Osman Mohammed Gaafer Abdelgfar , Szalai Márk , Zalai Mihály , Dorner Zita , Kiss Jozsef
Published: October 2022

Weeds are one group of pests that significantly reduce crop yields and qualities, while herbicide use poses a risk to human health and environment. Weed seed predation has been identified as a potential biocontrol approach offering sustainable weed management. It causes substantial seed losses on weed species in crop fields, and thus may result in a reduction in herbicide use. This study aimed to investigate the relevant seed predation patterns on important weed species, Galium aparine L., Papaver rhoeas L., and Apera spica-venti L., in a winter wheat field and the adjacent semi-natural habitat (SNH) near Gödöllő, Hungary, assuming that weed seeds are likely to be predated, but predation levels may differ by weed species and habitat type. Sampling rounds were performed twice, in 2019 and 2021, before crop harvest, by placing a total of 240 seed cards (120 cards/round) on the soil surface inside both crop field, and in the adjacent SNH. Seed predation was assessed on each card every 24 h, for 5 days in 2019 and 6 days in 2021. The results revealed high intensity (100%) of seed predation on the evaluated weed species, during the exposure periods in both years and habitat types, although weed seeds were significantly consumed (p < 0.001) in 2019 as opposed to 2021. Whereas, seed consumption levels were not significantly different (p = 0.802) among habitat types, and between habitats and years (p = 0.842). The optimum period for measuring weed seed predation was found to be after 48 h of field exposure. Our findings showed that seed predation reduced the number of exposed weed seeds on the soil surface, which may decrease the weed seed banks, and the number of weed seedlings the next cropping season.
Comparison of Yield and Important Seed Quality Traits of Selected Legume Species
Authors: Jarecki Wacław , Migut Dagmara
Published: October 2022

Legumes are of great economic importance. Depending on the species, they are cultivated for food, fodder, green manure, and even as ornamentals. Legume seeds contain many valuable nutrients and also anti-nutritional substances. The aim of the study is to compare important seed quality traits in pea (Pisum sativum L.), faba bean (Vicia faba L.), white lupin (Lupinus albus L.), narrow-leafed lupin (Lupinus angustifolius L.), and yellow lupine (Lupinus luteus L.) to soybean (Glycine max (L.) Merr.). It was shown that the obtained parameters were significantly affected by the interaction of species with the years of study. Soybean was characterized by high seed and protein yield and favorable seed chemical composition (protein, fat, phosphorus, potassium, magnesium, and micronutrients, except manganese). Faba bean yields were high but varied over the years. Faba bean seeds were rich in phosphorus and copper. Pea yielded satisfactorily, and the seeds contained high iron and low fiber contents. Of the three lupin species, white lupin yielded the highest, while narrow-leafed and yellow lupin yields were low. However, yellow lupin seeds had a favorable chemical composition because they were rich in protein, calcium, phosphorus, magnesium, copper, and zinc. In conclusion, legumes are valued worldwide and could be a base for the development of many functional foods to promote human health.
Supplementation of Soil with Waste Sulfur and Its Effect on Availability of Mn and Zn
Authors: Lisowska Aneta , Filipek-Mazur Barbara , Kalisz Andrzej , Gródek-Szostak Zofia , Kowalczyk Agnieszka
Published: October 2022

Sulfur is a necessary nutrient for the proper functioning of living organisms, both plants and animals. However, following pro-environmental activities carried out for many years, there is now a deficit of this element in the soils of many countries. The aim of this model study was to determine the effect of the application of waste elemental sulfur and its mixtures with organic materials (cattle manure, digestate and biochar) on the availability of manganese and zinc in soils. In addition to the standard analysis of variance (ANOVA), the authors propose various methods of advanced statistical analysis, e.g., simplified linear or polynomial regression model development, multiple regression analysis, heatmap statistics and principal component analysis (PCA). The presented findings indicate significant relationships between the soil pH value, S-SO4, Zn and Mn contents, dehydrogenase activity, and experimental duration. The results of regression analysis revealed that the applied materials had a more significant influence on the zinc content than on the manganese content during the incubation period.
The Dynamic Impacts of Weather Changes on Vegetable Price Fluctuations in Shandong Province, China: An Analysis Based on VAR and TVP-VAR Models
Authors: Yang Hongyu , Cao Yuanxin , Shi Yuemeng , Wu Yuling , Guo Weixi , Fu Hui , Li Youzhu
Published: October 2022

In order to enrich the research on the influence of weather factors on agricultural economy and provide practical decision-making references for the relevant market entities, this study took pointed pepper, loofah, Chinese chives and tomato as examples, using weekly wholesale prices and corresponding weather factors data from one of the main production areas in China based on the vector autoregressive (VAR) and the time-varying parameter vector autoregressive (TVP-VAR) models to explore the dynamic impacts of weather changes on vegetable price fluctuations. It was found that price fluctuations of specific vegetable varieties were affected by changes in specific weather factors. The shock intensity of weather factor changes in the same lag period on the current vegetable price fluctuations was time-varying, which could describe the historical dynamics of the impacts of weather changes on vegetable price fluctuations. The dissipation characteristics of the dynamic impacts of weather factors changes occurring at selected time points on vegetable price fluctuations had strong consistency, and the obtained rules could be used to analyze the life cycle and dynamic characteristics of extreme weather impacts on vegetable price fluctuations. In addition, vegetable price fluctuations were affected mostly by their own lag periods, and the shock intensity of vegetable price fluctuations with equal lag periods on their own current price fluctuations were relatively stable. The dynamic impacts of vegetable price fluctuations occurring at chosen time points on its own later fluctuations were highly consistent in the variation from the beginning of the strongest positive shock to the final dissipation.
N Utilization, Residual and Loss Characteristics of Spring-Topdressing (15N-urea) Pear Orchards in the Old Course of the Yellow River Area
Authors: Zhao Lin , Jia Zhihang , Li Gangbo , Zhang Ting , Wei Meng
Published: October 2022

In the old course of the Yellow River area, most orchards are over-applied with nitrogen (N) fertilizers. To improve N management in this area, a 15N tracing experiment was conducted to investigate the absorption, distribution and loss of spring-topdressing urea in pear orchards from March to August 2019. The 7-year-old Sucui 1 pear was used as the test material, and 277.5 g of ordinary urea and 15 g of 15N-urea N were evenly applied to each plant. The N absorption, distribution and utilization efficiency of different organs from the flowering stage to the post-harvest stage were analyzed, and the residual and loss of N in the soil were also discussed. The N fertilizer utilization rate increased with the advancement of the phenological period. The N fertilizer utilization rate in the full bloom period is 10.39%, which is the fastest growing period, and reached a maximum of 23.62% in the post-harvest stage. In the young fruit stage, the amount of N derived from labeled fertilizer (%Ndff) of the fruit was only 1.02%, and most of the new vegetative organs were above 1%. Residual amount in the 20–40 cm soil layer was significantly higher than that in other soil layers. Direction of N fertilizer is N fertilizer loss>soil residue>tree absorption. N loss in the fruit expansion stage and the harvest stage is higher, which are 3.76 g and 3.74 g, respectively. N utilization rate in this area is low throughout the year. There is nutrient competition between reproductive growth and vegetative growth, which can be effectively alleviated by spring top-dressing. The N loss during fruit expansion and harvesting is serious. Attention should be paid to split fertilizer application and the timely supplementation of an appropriate amount of N fertilizer to improve N use efficiency.
Brevibacillus laterosporus as a Natural Biological Control Agent of Soil-Dwelling Nematodes
Authors: Hamze Rim , Ruiu Luca
Published: October 2022

The nematocidal potential of an entomopathogenic strain of Brevibacillus laterosporus previously known for its antimicrobial properties was assessed on the free-living nematode microworm Panagrellus redivivus and the root-knot nematode Meloidogyne incognita. Laboratory bioassays showed significant nematocidal properties of the culture supernatant of the bacterium, achieving over 90% mortality of both microworms and M. incognita juveniles when the supernatant was collected at the sporulation phase, which related to the progressive production and release of virulence factors and toxins in the culture medium at this stage of bacterial growth. A protein fraction obtained by precipitation from the bacterial culture supernatant was found to be very active against nematodes with a concentration-dependent effect and an LC50 value of 0.4 µg/µL on M. incognita. Bacterial preparations based on either spores or a culture supernatant proved to be effective in reducing M. incognita density in treated compared with untreated soil, which makes the use of B. laterosporus as a biological control agent of soil-dwelling nematode pests particularly promising.
Estimating Sheet Flow Velocities Using Quinine as a Fluorescent Tracer: Bare, Mulched, Vegetated and Paved Surfaces
Authors: Zehsaz Soheil , de Lima João L. M. P. , de Lima M. Isabel P. , Isidoro Jorge M. G. P. , Martins Ricardo
Published: October 2022

When direct flow velocity measurements are not feasible, the use of tracers can be a valuable tool. In the present study, both laboratory and field experiments were conducted to evaluate the applicability of quinine as a fluorescent tracer for estimating mean sheet flow velocities in different ambient light and surface morphology conditions. Quinine excels in low-light conditions when exposed to UVA light. This tracer was compared with dye and thermal tracers, all in liquid form. In these tracing techniques the tracers were injected into the flow, after which surface velocity was estimated by tracking the leading edge of the tracer plumes and applying a correction factor to calculate the mean velocity (in a water column). The visibility of the tracers was evaluated by measuring the relative luminance and contrast ratio of the quinine and dye tracer plumes. Results show that the quinine tracer can be used to estimate sheet flow velocities over a wide variety of soil and urban surfaces; it has better visibility in comparison to the dye tracer but, in some conditions, lower visibility than the thermal tracer. Although quinine is invisible under bright ambient light conditions, this tracer technique requires low-cost experimental setup and is useful in low-light conditions (e.g., night; twilight; shielded environments).