bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical and Numerical Study on Dynamic Response of Propellant Actuator
Authors: Xu Pengzhao , Zhao Ning , Shi Kunlin , Cui Shaokang , Chen Chi , Liu Jun
Published: October 2022

In order to solve the complexity of the structure, assembly process, component contact state and working process of the propellant actuator by conventional methods, a novel design method based on theoretical and numerical analysis was proposed. The internal ballistic model of the propellant actuator was established based on the classical internal ballistic theory, and the pressure–time characteristic curve of the propellant gas was then obtained. According to the characteristic curve, the dynamic characteristics of the piston under different design conditions of the shear slice were calculated by numerical simulation. The results show that the pressure–time characteristics of the internal ballistic model were in good agreement with the experimental data, indicating that the the internal ballistic model of the propellant actuator is reasonable. Additionally, the structure optimization design and drop safety of the propellant actuator were carried out using the finite element method. It was found that with increasing the propellant charge, the movement time of the piston decreases and the maximum velocity increases. Moreover, the critical values of the propellant charge are 5 mg, 6 mg, 7 mg for the thickness of the shear slice of 0.2 mm, 0.3 mm and 0.4 mm, respectively.
Examining the Mediating Role of Work Engagement in the Relationship between Corporate Social Responsibility and Turnover Intention: Evidence from Nigeria
Authors: Bayode Olubanke Tolulope , Duarte Ana Patrícia
Published: October 2022

The subject of corporate social responsibility (CSR) has drawn the attention of many scholars and practitioners in the administrative sciences field. However, few studies have been carried out on Nigerian employees’ perspectives on CSR and on how CSR affects their attitudes and behaviors at work. The present study sought to contribute to narrowing this gap by examining how CSR perceptions, work engagement, and turnover intention are related in a sample of Nigerian workers. More specifically, this study had triple aims: first, describe employees’ perceptions of their employers’ involvement in different CSR domains; second, examine how CSR perceptions were related to employees’ levels of work engagement and turnover intention; third, analyze work engagement intervention as a mediator in the relationship between CSR perceptions and turnover intention. The sample included 118 employees from different organizations who voluntarily participated in an online survey. The findings revealed that respondents consider that their employer organizations have relatively high involvement in CSR activities, especially activities towards customers, employees, and stockholders. Findings also revealed that employees’ perceptions of CSR are related to diminishing levels of turnover intention, via increased work engagement. Therefore, organizations can invest in CSR activities to foster positive employee outcomes in Nigeria.
Controlling Aircraft Inter-Arrival Time to Reduce Arrival Traffic Delay via a Queue-Based Integer Programming Approach
Authors: Higasa Koki , Itoh Eri
Published: October 2022

Despite the importance of controlling the inter-arrival times of flights to propose strategies for efficient arrival management by the Arrival Manager (AMAN), the specific guidelines of such adjustments and their effect on reducing delays have not been explicitly considered. Accordingly, this paper proposes a novel approach, which integrates the Gt/GI/st+GI time-varying fluid model and nonlinear integer programming to flatten the arrival rate at terminal gates. This, in turn, is achieved by minimizing the variance in inter-arrival times by penalizing any excessive change in arrival time, considering operational constraints. The results for Tokyo International Airport show potential to significantly reduce arrival traffic delays by minimizing said variance. This study may also spawn subsequent work, which builds a queuing network comprising upstream and terminal airspace and demonstrates the scope to reduce delays in the terminal airspace by controlling inter-arrival times at the upstream airspace.
Selection Rules for Resonant Longitudinal Injector-Coupling in Experimental Rocket Combustors
Authors: Horchler Tim
Published: October 2022

This paper investigates different types of longitudinal mode coupling in subscale rocket combustion chambers using experimental data and numerical simulations. Based on a one-dimensional planar wave acoustic model of coupled cavity resonators with two acoustic inlet boundary conditions, mode selection rules are derived, providing a simple way of predicting which injector and combustion chamber modes have matching frequencies. Longitudinal mode coupling of an injector with an acoustically open inlet boundary condition has been reported in the literature for the start-up transient of a research combustor experiment. In this experiment, every third injector mode couples to a corresponding chamber longitudinal mode, which is explained in terms of the selection rules derived in this paper. Numerical simulation results for a different combustor experiment show an unexpected mode coupling behavior when an acoustically closed injector inlet is used. Theoretical analysis by using the one-dimensional wave model and applying the derived selection rules shows that in this setup, the injector acoustic mode can accommodate two different acoustic boundary conditions at the injector-chamber interface simultaneously. This results in different acoustic mode shapes in the injector, explaining the unexpected behavior for the resonant coupling with an acoustically closed injector inlet.
Last Decade Assessment of the Impacts of Regional Climate Change on Crop Yield Variations in the Mediterranean Region
Authors: Alrteimei Hanan Ali , Ash’aari Zulfa Hanan , Muharram Farrah Melissa
Published: October 2022

The influence of regional climate change (CC) on agricultural production variance in the Mediterranean region has been discussed based on the assessment of the last decade. Most of the Mediterranean region has experienced frequent natural disasters, expanding population, increase in temperature, and increase in the surface of the Mediterranean Sea. Furthermore, the temperature in the Mediterranean area is rising 25% faster than the rest of the globe, and in the summer, it is warming 40% faster than the global average. Climate change can alter the food supply, restrict access to food, and degrade food quality. Temperature rises, changes in precipitation patterns, changes in severe weather events, and decreased water availability, for example, might all result in lower agricultural production. The fact that most Mediterranean nations rely on imported basic foodstuffs adds to the severity of the situation. Instability and insecurity of agricultural supply in the region might lead to massive population movement, transforming most Mediterranean nations into a global source of instability. Based on the experience of similar geographical locations, the article has highlighted the essential elements affecting crop productivity and the five domains of water, ecosystems, food, health, and security. Despite the region’s complexity, the Mediterranean region has been offered an overall assessment that predicts the best strategy for the best solution. Such an attempt describes a methodical integration of scientific discoveries to understand better the combined hazards illustrated by the fact that CC has affected food production, resulting in widespread insecurity. Utilizing current technologies in agricultural production has been recommended to support regional nations in reaching higher yields. The significance of this study could be realized by mitigating climatic shocks through a sustainable food production system to accomplish development goals in vulnerable nations.
Genetic Improvement of Sugarcane (Saccharum spp.) Contributed to High Sucrose Content in China Based on an Analysis of Newly Developed Varieties
Authors: Zhao Yong , Liu Jiayong , Huang Hairong , Zan Fenggang , Zhao Peifang , Zhao Jun , Deng Jun , Wu Caiwen
Published: October 2022

In China, sugarcane (Saccharum spp.) hybrid cross-breeding began in 1953; approximately 70 years since then, >100 commercial sugarcane varieties have been created. In this study, 88 commercial varieties bred in China between 1953 and 2010 and 12 original foundational varieties were planted to investigate the effect of improving sugarcane varieties in China. Considering 20 years as a time node, the commercial varieties were classified into four improved generations. Retrospective analysis showed significant improvements in sucrose and other technological characteristics of commercial sugarcane varieties. The adoption of improved varieties over generations has continuously increased sugarcane’s sucrose, juice sugar, and gravity purity, and the difference was significant between Gen1 and Gen3, and between Gen2 and Gen4. Gen4 showed 2.06%, 2.35%, and 3.69% higher sugarcane sucrose (p < 0.01), juice sugar (p < 0.01), and purity (p < 0.05), respectively, and 1.13% lower sugarcane fiber (p < 0.01) than Gen1, the original foundational hybrid varieties. The development of new varieties has improved the technological characteristics of Chinese sugarcane. Sugarcane sucrose, juice sugar, and purity showed an increasing trend. Sugarcane fiber content did not significantly change with the development of new varieties but declined in comparison with the original foundational hybrid varieties.
Coupling Process-Based Crop Model and Extreme Climate Indicators with Machine Learning Can Improve the Predictions and Reduce Uncertainties of Global Soybean Yields
Authors: Sun Qing , Zhang Yi , Che Xianghong , Chen Sining , Ying Qing , Zheng Xiaohui , Feng Aixia
Published: October 2022

Soybean is one of the most important agricultural commodities in the world, thus making it important for global food security. However, widely used process-based crop models, such as the GIS-based Environmental Policy Integrated Climate (GEPIC) model, tend to underestimate the impacts of extreme climate events on soybean, which brings large uncertainties. This study proposed an approach of hybrid models to constrain such uncertainties by coupling the GEPIC model and extreme climate indicators using machine learning. Subsequently, the key extreme climate indicators for the globe and main soybean producing countries are explored, and future soybean yield changes and variability are analyzed using the proposed hybrid model. The results show the coupled GEPIC and Random Forest (GEPIC+RF) model (R: 0.812, RMSD: 0.716 t/ha and rRMSD: 36.62%) significantly eliminated uncertainties and underestimation of climate extremes from the GEPIC model (R: 0.138, RMSD: 1.401 t/ha and rRMSD: 71.57%) compared to the other five hybrid models (R: 0.365–0.612, RMSD: 0.928–1.021 and rRMSD: 47.48–52.24%) during the historical period. For global soybean yield and those in Brazil and Argentina, low-temperature-related indices are the main restriction factors, whereas drought is the constraining factor in the USA and China, and combined drought–heat disaster in India. The GEPIC model would overestimate soybean yields by 13.40–27.23%. The GEPIC+RF model reduced uncertainty by 28.45–41.83% for the period of 2040–2099. Our results imply that extreme climate events will possibly cause more losses in soybean in the future than we have expected, which would help policymakers prepare for future agriculture risk and food security under climate change.
The Design and Experiment of Vertical Variable Cavity Base Fertilizer Fertilizing Apparatus
Authors: Zhang Xiuli , Pei Yikun , Chen Yong , Song Qianglong , Zhou Peilin , Xia Yueqing , Liu Xiaochan
Published: October 2022

A vertical variable cavity organic fertilizer and compound fertilizer apparatus were designed according to tobacco farming requirements to overcome issues of unstable fertilizer discharge and blocking in the fertilizer disk of an existing fertilizer apparatus. The structure and working principle of the fertilizer apparatus were described. Combined with the principle of anti-arch and the requirements of fertilizer application, the structure size of the fertilizer apparatus was determined. Using the opening degree and rotational speed of the fertilizer disk as the test factors and the fertilizer rate and variation coefficient of fertilizer application rate as the indices, the EDEM was used to conduct the single factor test and obtain the appropriate rotational speed range. The results indicated that the variation coefficient of the fertilizer uniformity apparatus was 0.96–5.22% under different rotation speeds and fertilizer disk openings, which satisfied design requirements. The orthogonal experiment explored the interaction between rotational speed and the opening. The influence of the opening adjustment on the fertilizer application rate and the coefficient of variation of uniformity were greater than the change in fertilizer disk speed. The bench and field tests aligned with the simulation test. These findings provide a reference and theoretical basis to design a fertilizer apparatus.
Titanium Organic Complex Improves Pollination and Fruit Development of Remontant Strawberry Cultivars under High-Temperature Conditions
Authors: Bieniasz Monika , Konieczny Anna , Błaszczyk Jan , Nawrocki Jacek , Kopeć Michał , Mierzwa-Hersztek Monika , Gondek Krzysztof , Zaleski Tomasz , Knaga Jarosław , Pniak Michał
Published: October 2022

Heat stress negatively affects pollination, fertilization, and consequently, the development of strawberry fruits. It was proved that foliar application of titanium organic complex improved pollination and fertilization processes of some plant species, which resulted in better fruit development. Therefore, a three-year experiment was designed to determine the effect of the titanium organic complex on pollination and fertilization processes and consequently on fruit development of three remontant strawberry cultivars grown under canopies, under conditions of high temperature. The experiment demonstrated that high temperature disrupted the flowering physiology of strawberry. Under such conditions, the viability and germination of pollen as well as the receptivity of stigma were significantly reduced. The application of titanium organic complex during flowering had a beneficial effect on the pollination and fertilization processes of strawberries. Plants treated with the titanium organic complex were characterized by higher pollen viability, better pollen germination, a higher number of achenes in fruit, and a higher weight of individual fruit, compared to the not treated plants. The obtained results suggest that application of titanium organic complex during flowering may alleviate the stress caused by high temperature and contribute to the improvement of the quantity and quality of a crop.
Detection of Water Content in Lettuce Canopies Based on Hyperspectral Imaging Technology under Outdoor Conditions
Authors: Zhao Jing , Li Hong , Chen Chao , Pang Yiyuan , Zhu Xiaoqing
Published: October 2022

To solve the problem of non-destructive crop water content of detection under outdoor conditions, we propose a method to predict lettuce canopy water content by collecting outdoor hyperspectral images of potted lettuce plants and combining spectral analysis techniques and model training methods. Firstly, background noise was removed by correlation segmentation, proposed in this paper, whereby light intensity correction is performed on the segmented lettuce canopy images. We then chose the first derivative combined with mean centering (MC) to preprocess the raw spectral data. Hereafter, feature bands were screened by a combination of Monte Carlo uninformative variable elimination (MCUVE) and competitive adaptive reweighting sampling (CARS) to eliminate redundant information. Finally, a lettuce canopy moisture prediction model was constructed by combining partial least squares (PLS). The correlation coefficient between model predicted and measured values was used as the main model performance evaluation index, and the modeling set correlation coefficient Rc was 82.71%, while the prediction set correlation coefficient RP was 84.67%. The water content of each lettuce canopy pixel was calculated by the constructed model, and the visualized lettuce water distribution map was generated by pseudo-color image processing, which finally revealed a visualization of the water content of the lettuce canopy leaves under outdoor conditions. This study extends the hyperspectral image prediction possibilities of lettuce canopy water content under outdoor conditions.
Optimal Nitrogen Rate Increases Water and Nitrogen Use Efficiencies of Maize under Fully Mulched Ridge–Furrow System on the Loess Plateau
Authors: Xie Junhong , Wang Linlin , Li Lingling , Anwar Sumera , Luo Zhuzhu , Fudjoe Setor Kwami , Meng Haofeng
Published: October 2022

Increasing water and nitrogen use efficiencies (i.e., WUE and NUE) in dryland agroecosystems to maintain high agricultural output with lower environmental costs, such as minimal soil water depletion and nitrate-N residue, are key responsibilities to assure food security for a growing global population. The impact of N rate on soil water balance, soil nitrate N residue, grain yield, WUE, crop N recovery efficiency (REN), agronomic use efficiency of N fertilizer (AE), and net economic return were examined on maize production on the rainfed Loess Plateau during 2011–2018. Field treatments included four N application rates (N0, no N fertilizer applied; N100, 100 kg N ha−1; N200, 200 kg N ha−1; N300, 300 kg N ha−1). Results showed that compared with N0, grain yield increased by 56, 110, and 115% under N100, N200, and N300, respectively, with corresponding improvements in net economic return of 5497, 10,878, and 11,088 RMB ha−1 yr−1, respectively; no significant difference was detected between N200 and N300. Compared to N0, N fertilization significantly increased WUE through improving photosynthetic WUE (i.e., transpiration efficiency), but there was no significant difference between N200 and N300. Compared to N100, the REN was gradually decreased as N rates increased, AE was not significantly changed under N200 and significantly decreased under N300 due to a decreased leaf photosynthetic NUE. Compared to original soil water storage at 0–300 cm soil depths, after seven years of continuous experiments, treatment of N0 enhanced soil water storage by 52 mm and treatment of N100 had no effect on soil water storage, but treatments of N200 and N300 depleted soil water storage by 73 and 109 mm, respectively. Our findings showed that 200 kg N ha−1 improves WUE and NUE with less environmental cost and should be regarded as the economically optimal N rate on the semiarid western Loess Plateau of China for sustainable maize production.
Does Farm Size Expansion Improve the Agricultural Environment? Evidence from Apple Farmers in China
Authors: Cheng Juanjuan , Wang Qian , Zhang Huanmin , Matsubara Toyohiko , Yoshikawa Naoki , Yu Jin
Published: October 2022

Farmland environmental pollution has put greater pressure on the sustainability of agricultural production systems. Exploring the relationship between farm size and environmental pollution in agriculture can help provide realistic guidance for stakeholders. In this study, the research data from apple farmers in China were used to measure the environmental pollutant emissions caused by apple production using the life-cycle assessment (LCA) approach. The mediating effect model was used to examine the mechanisms and pathways by which farm size affects the environmental effects of apple production and to identify the mediating effects of fertilizer, pesticide, and machinery input intensity. Finally, a heterogeneity analysis was conducted to illustrate the impact of participation in agricultural cooperatives on the environmental performance of apple production for smallholder farmers. The results showed that the apple production system’s negative environmental impacts from the agricultural material production phase were more significant compared to the farming phase, with a contribution potential of 56.50%. Farm size directly impacts the environmental effects of apple production, and there is a U-shaped trend between the two, implying that from the perspective of environmental effects, larger farm size is not better. There were some mediating effects in the paths of farm size on the environmental effects, and the largest effect was fertilizer input intensity with a full mediating effect; the second largest effect was machinery input intensity with a partial mediating effect, and the mediating effect accounted for 15.50–15.89% of the total effect; the mediating effect of pesticide input intensity was not significant. In addition, the study also found that joining agricultural cooperatives was beneficial in promoting the improvement of the negative environmental impact caused by apple production. These findings provide insights into optimizing farm inputs for apple production and identifying the appropriate farm size to alleviate multiple environmental impacts, intending to make a marginal contribution to promoting sustainable development of the apple industry in China also providing the research evidence for the comparative study of the environmental burdens of apple production in China and other countries in the world.
A Soft Gripper Design for Apple Harvesting with Force Feedback and Fruit Slip Detection
Authors: Chen Kaiwen , Li Tao , Yan Tongjie , Xie Feng , Feng Qingchun , Zhu Qingzhen , Zhao Chunjiang
Published: October 2022

This research presents a soft gripper for apple harvesting to provide constant-pressure clamping and avoid fruit damage during slippage, to reduce the potential danger of damage to the apple pericarp during robotic harvesting. First, a three-finger gripper based on the Fin Ray structure is developed, and the influence of varied structure parameters during gripping is discussed accordingly. Second, we develop a mechanical model of the suggested servo-driven soft gripper based on the mappings of gripping force, pulling force, and servo torque. Third, a real-time control strategy for the servo is proposed, to monitor the relative position relationship between the gripper and the fruit by an ultrasonic sensor to avoid damage from the slip between the fruit and fingers. The experimental results show that the proposed soft gripper can non-destructively grasp and separate apples. In outdoor orchard experiments, the damage rate for the grasping experiments of the gripper with the force feedback system turned on was 0%; while the force feedback system was turned off, the damage rate was 20%, averaged for slight and severe damage. The three cases of rigid fingers and soft fingers with or without slip detection under the gripper structure of this study were tested by picking 25 apple samples for each set of experiments. The picking success rate for the rigid fingers was 100% but with a damage rate of 16%; the picking success rate for soft fingers with slip detection was 80%, with no fruit skin damage; in contrast, the picking success rate for soft fingers with slip detection off increased to 96%, and the damage rate was up to 8%. The experimental results demonstrated the effectiveness of the proposed control method.
Degree Days as a Method to Estimate the Optimal Harvest Date of ‘Conference’ Pears
Authors: Łysiak Grzegorz P.
Published: October 2022

The European pear is a climacteric fruit species characterised by high storability. The ‘Conference’ pear can be stored in a CA (controlled atmosphere) room without major losses for half a year. However, for ‘Conference’ storage to be successful, the fruit must be harvested when fully developed before it enters the climatic maturation phase. Among the various methods used to determine the optimal harvest date, the degree-day method, which relies on the sum of active temperatures, seems to be relatively accurate and easy to apply. During 11 years of study, pears were harvested on four dates (every 4–5 days) chosen based on measurements and observations, and then, after a six-month storage period, the optimal harvest date was determined. During the growing season, the temperature was measured using an automatic weather station to calculate the sum of active temperatures from full bloom to the optimal harvest date. Measurements made after storage were analysed, and the sum of active temperatures needed for the proper development of the ‘Conference’ pear was calculated to be 2469 degree days. The calculations are very accurate because the dispersion calculated using the standard deviation was only 20°. The base temperature with the smallest error was 0 °C. This study shows that this method can be recommended as useful for determining the optimal harvest date.
Influence of Livelihood Capital Level and Structure on Rural Households’ Payment Willingness for Rural Human Settlement Improvement: Evidence from Hubei Province, China
Authors: Cui Yongzheng , Wang Wenxiong , Yu Lihong , Zhou Wei , Fu Zitong
Published: October 2022

Rural human settlement improvement (RHSI) is the basis for enhancing rural households’ life quality and promoting their well-being. Studying the impact of the livelihood capital level and structure on rural households’ payment willingness for RHSI will help to clarify the effective focus for implementing a payment system for rural environmental governance, which is of great significance for improving rural human settlements and promoting comprehensive rural revitalization. This study reveals the influence mechanism of the livelihood capital level and structure on rural households’ willingness to pay (WTP) for RHSI. According to the survey data of rural households in Hubei Province, China, the level and structure of rural households’ livelihood capital and their WTP for RHSI are analyzed using the entropy value method and the contingent valuation method. The effects of the livelihood capital level and structure on rural households’ WTP for RHSI are tested using the Probit and Tobit models. The results show significant differences in the level and structure of rural households’ livelihood capital. More than half of the rural households have a payment inclination for RHSI, but the distribution of the willingness payment amounts shows a clear polarization, with the average payment amount ranging from CNY 14.48 to 28.32 per month. Both the total livelihood capital level and classification levels (natural capital, human capital, financial capital and social capital) significantly positively affect the rural households’ WTP. In the livelihood capital structure, both the natural-capital-dominant type and financial-capital-dominant type significantly positively affect the rural households’ WTP, and the human-capital-dominant type significantly positively affects the rural households’ willingness payment amount. Accordingly, this study proposes policy recommendations for the multi-dimensional improvement of rural households’ livelihood capital and the optimization of the livelihood capital structure allocation.
Coupling Coordination and Spatiotemporal Dynamic Evolution between Agricultural Carbon Emissions and Agricultural Modernization in China 2010–2020
Authors: Xia Mengyao , Zeng Di , Huang Qi , Chen Xinjian
Published: October 2022

Modern agriculture contributes significantly to greenhouse gas emissions. How to reduce such emissions without sacrificing agricultural development is a common issue concerning most developing countries. In China, a rural revitalization strategy proposed in 2018 aims to achieve agricultural modernization by 2050, while reaching a carbon emission peak by 2030 and neutrality by 2060. However, China’s progress towards these goals is largely unknown. This study evaluates the coupling coordination and spatiotemporal dynamic evolution between agricultural carbon emissions and agricultural modernization in China from 2010 to 2020 through a joint employment of spatial autocorrelation and coupling coordination degree modeling. The results show that from 2010 to 2020, the agricultural modernization level increased from 0.155 to 0.272, and the agricultural carbon emission intensity decreased from 4.9 tons per 10 thousand CNY to 2.43 tons. Agricultural carbon emissions and the agricultural modernization level manifest significant spatially agglomerative patterns with noticeable discrepancies across different regions. Moreover, the coupling coordination degree between agricultural carbon emissions and agricultural modernization has increased every year, but disparities among provinces continued to widen. Specifically, coupling coordination in northern China is significantly higher than that in the south, and its spatial distribution exhibits a positive correlation and increasing levels of clustering. These results point to the continued need for sustainable agricultural development efforts, such as strengthening rural infrastructure and diffusing green technologies in achieving China’s dual carbon emission and agricultural modernization goals. This study also examines the sustainable agricultural development issue from a new perspective, and the findings can provide policy references for sustainable agricultural development policies in China.
Farmers’ Preferred Genotype Traits and Socio-Economic Factors Influencing the Adoption of Improved Cowpea Varieties in South-Central Niger
Authors: Rabé Mahamane Moctar , Baoua Ibrahim B. , Baributsa Dieudonne
Published: October 2022

Cowpea, Vigna unguiculata (L.) (Walpers, 1842), is an important legume for food and nutrition security, and income generation. Despite decade-long efforts to disseminate improved varieties, cowpea productivity remains low in Niger. This is due, in part, to the limited adoption of improved cowpea varieties among farmers. Increasing the adoption of improved cowpea varieties requires a better understanding of farmers’ preferred genotype traits and socio-economic factors that influence their decision. We interviewed 634 farmers from the south-central regions (Maradi and Zinder) of Niger to assess factors that influence their decision to adopt improved cowpea varieties. The average age of the respondent was 41 years with 29 years of farming experience. Eight improved cowpea varieties were grown by these farmers with average adoption rates ranging from 3.3 to 38.0%. Genotype traits that influenced farmers’ decision to adopt improved cowpea varieties included early maturing (86.9%), high yielding (73.9%), and high market value (50.5%). Socio-economic factors that significantly influenced adoption were age, gender, membership in a farmers’ organization, and contact with the extension services. Adoption is constrained by the limited availability of cowpea varieties with farmers’ preferred genotypes traits. Farmers’ preferences for genotype traits must be considered in the early stages of breeding programs and the release of new varieties to increase adoption. Stakeholders involved in the cowpea value chain can use this information to improve cowpea adoption and productivity.
Nitrogen Sources in Young Peach Trees in the Presence and Absence of Paspalum notatum Co-Cultivation
Authors: Paula Betania Vahl de , Rozane Danilo Eduardo , Santos Eduardo Maciel Haitzmann dos , Vitto Beatriz Baticini , Hindersmann Jacson , Antunes Luis Eduardo Correa , Nava Gilberto , Loss Arcângelo , Melo George Wellington Bastos de , Nicoloso Fernando Teixeira , Brunetto Gustavo
Published: October 2022

Nitrogen (N) sources are applied to soils cultivated with peach trees. But, soil cover crops, as Paspalum notatum, a Pampa biome native species, commonly present in orchards, can absorb part of N, decreasing the amount used by peach trees. The study aimed to evaluate N absorption and physiological parameters of young peach trees cultivated in soil with the presence and absence of Paspalum notatum. The experiment was carried out for 180 days in a greenhouse, where N sources were applied to peach trees in the presence or absence of Paspalum notatum. Urea and organic compost were used. Dry matter, tissue N and physiological parameters were evaluated in peach trees. Dry matter and tissue N were evaluated in Paspalum notatum. Nitrogen in soil was evaluated. The N uptake by the peach trees with urea application, on average, was 32% higher than the N uptake by the peach trees in the control treatment or with organic compost, regardless of the presence or absence of Paspalum notatum. Cultivation with Paspalum notatum decreased N uptake by peach trees and, consequently, peach trees photosynthetic pigment content, and stimulated senescence anticipation in about 30 days. However, the total dry matter of peach trees cultivated with Paspalum notatum in any of the treatments applied was not modified. These results may guide new ways of co-cultivating cover crops and young peach trees.
The Effects of Winter Cover Crops on Maize Yield and Crop Performance in Semiarid Conditions—Artificial Neural Network Approach
Authors: Vojnov Bojan , Jaćimović Goran , Šeremešić Srđan , Pezo Lato , Lončar Biljana , Krstić Đorđe , Vujić Svetlana , Ćupina Branko
Published: October 2022

Maize is the most widespread and, along with wheat, the most important staple crop in the Republic of Serbia, which is of great significance for ensuring national food security. With the increasing demand for food and forage, intensive agricultural practices have been adopted in the maize production systems. In this direction, considerable research efforts have been made to examine the effects of different types of cover crops as a green manure on maize productivity; however, no consistent conclusions have been reached so far. Therefore, the objective of the present study is to examine the possibility of predicting the effects of winter cover crops (CC) integrated with different management practices on the morphological traits, yield, and yield components of maize. The experiment was carried out on chernozem soil from 2016 to 2020 as a randomized complete block design arranged as a split-split-plot with three replicates. The pea as a sole crop (P) and the mixture of pea and triticale (PT) are sown as winter CC with the following subplots: (i) CC used as green manure, and (ii) CC used as forage and removed before maize sowing. The artificial neural network is used for exploring nonlinear functions of the tested parameters and 13 categorical input variables for modeling according to the following factors: CC, way of using CC, N fertilization, and year. The computed maximums of plant height, number of leaves, number of internodes, plant density, number of ears, grain yield, 1000-grain weight, hectolitre weight, dry matter harvest residue, harvest index, leaves percentage, stems percentage, and ears percentage are as follows: 232.3 cm; 9.7; 10.2; 54,340 plants ha−1; 0.9; 9.8 t ha−1; 272.4 g; 67.0 kg HL−1; 9.2 t ha−1; 0.52; 18.9%; 36.0%, and 45.1%, respectively. The optimal result is obtained with peas used as green manure, with 50 kg N ha−1 and in the climatic conditions of 2018. Consequently, maize production under subsequent sowing periods can be successfully optimized by adapting selected management options for higher yield accomplishment.
Characterization of Root Morphology and Anatomical Structure of Spring Maize under Varying N Application Rates and Their Effects on Yield
Authors: Li Xiangling , Wang Rui , Zhou Baoyuan , Wang Xinbing , Wang Jian , Zhao Ming , Li Congfeng
Published: October 2022

Root morphology is an important factor determining nitrogen (N) uptake by plants, which might be affected by the extent of N application. The processes associated with root morphogenesis of spring maize in response to N application rates remain poorly understood. In this study, both field and pot experiments were conducted to explore the effect of zero-N (N0), optimized-N (N180), and high-N (N360) on root morphology, anatomical structure, and N accumulation in spring maize. N application rates affected root length and surface area, and its endogenous hormone contents. The largest difference in total root length and surface area among the three N rates was found at the silking stage: the total root length and surface increased by 51.36% and 42.58% under N180 and by 7.8% and 30.14% under N360, respectively, compared with N0, and the root/shoot ratio and root bleeding sap significantly increased under N180 and N360 compared with N0. The auxin and jasmonic acid levels of roots under N180 and N360 were higher than N0. N application rates also affected root microstructure and ultrastructure. Compared with N0, the proportions of root aerating tissue under N180 and N360 were decreased by 32.42% and 11.92% at silking. The root tip cell structure was damaged under N0, and intact under N180 and N360. Moreover, the 15N allocation proportions to root and grain under N180 and N360 were increased compared to N0. Grain yields under N180 and N360 increased by 20.44% and 16.6% compared with N0, respectively. It can be concluded that optimized-N application decreased root aerated tissue and thus improved root length and root surface area through regulating auxin and jasmonic acid levels and affected N uptake and grain yield of N-efficient spring maize variety.
An Investigation into Using Temporary Immersion Bioreactors to Micropropagate Moringa oleifera Lam. Callus, Roots, and Shoots
Authors: Coetser Elmien , du Toit Elsa S. , Prinsloo Gerhard
Published: October 2022

Moringa oleifera Lam., a tree naturally grown in the tropics, is becoming increasingly popular as an industrial crop due to its multitude of useful attributes. Therefore, this study tested the effect of temporary immersion system (TIS) bioreactors for mass micropropagation of Moringa oleifera Lam. callus, roots, and shoots. TIS are tissue culture systems that make use of timers to periodically immerse and drain plant cultures in a liquid nutrient medium instead of using solidified media. In initial studies, Moringa oleifera seeds were germinated in vitro, and in vitro seedling leaflets were then used as explant material for callus production on the pre-culturing media. Two experiments were conducted to improve the protocol for TIS bioreactor production. The first experiment investigated the effect of 6-benzylaminopurine (BA) and kinetin, whereas experiment 2 was conducted to improve shooting production. For the first experiment, leaf material was cultured onto a solidified medium consisting of half-strength Murashige and Skoog (MS) basal salts and 0.5 ppm 1-naphthaleneacetic acid (NAA) to initiate callus production before splitting it between solidified media and bioreactors for shooting. The shooting media consisted of full-strength MS basal salts and different treatments of kinetin and BA. A significant increase in callus production was observed with the use of TIS bioreactors, compared to solidified media, whereas root production had a highly significant interaction effect between the media and the cytokinin treatments. With shoot proliferation in mind, experiment 2 was performed, where microcuttings from in vitro-grown seedlings were excised and cultured onto a solidified MS medium, consisting of a control (0 ppm BA) and two different concentrations of 6-benzylaminopurine (BA) (0.1 ppm BA and 0.2 ppm BA) in the pre-culturing phase. Microcuttings were again excised after two weeks and transferred to the shooting media containing 0.1 ppm BA in TIS bioreactors and semi-solidified medium. Results showed TIS bioreactors to be effective in increasing both the amount and length of shoots produced. Shoot and callus fresh weights were also higher in explants cultured in TIS bioreactors. The results of this study also suggest M. oleifera sensitivities to plant growth regulators (PGRs). In conclusion, this study successfully produced callus, roots, and shoots in both the solidified media and TIS bioreactors, emphasizing the prospect of using TIS bioreactors for mass micropropagation of M. oleifera callus, roots, and shoots.
Geostatistical Methods to Build Citrus Cross-Pollination Risk Maps
Authors: Moltó Enrique , Orts Carmen , Pardo José L. , Izquierdo-Sanz Héctor
Published: October 2022

Valencian citriculture is oriented towards fresh production, which requires fruits with few seeds or seedless fruits. Consequently, parthenocarpic and self-incompatible varieties are mainly cultivated. However, some mandarin varieties, under favorable circumstances, induce seed formation in other mandarins by cross-pollination. This phenomenon depends on the germination capacity of the pollen of the pollinating variety, the number of ovules of the pollinated variety, the distance between them, and the abundance of pollinating insects. Previous studies in Instituto Valenciano de Investigaciones Agrarias (IVIA) have determined the ability to pollinate and be pollinated by all commercial varieties in Europe. Moreover, the Regional Government, Generalitat Valenciana, has georeferenced information on the cultivated varieties. We present two geostatistical models to estimate the risk of plots to be pollinated, depending on the varieties present in their environment, the number of plants, and their distance. Models are used to generate local and regional cross-pollination risk maps. Moreover, the robustness of these models to changes in the values assigned to their main parameters is assessed using different similarity calculations.
Effects of Water-Fertilizer-Air-Coupling Drip Irrigation on Soil Health Status: Soil Aeration, Enzyme Activities and Microbial Biomass
Authors: Lei Hongjun , Yu Jie , Zang Ming , Pan Hongwei , Liu Xin , Zhang Zhenhua , Du Jun
Published: October 2022

In order to investigate the effects of water-fertilizer-air-coupling drip irrigation on soil health status, including soil aeration (SA), enzyme activity (EA) and microbial biomass (MB), and its response relationship, this glasshouse experiment was conducted using tomato as the test crop, and we designed two fertilization gradients of 135 and 180 kg N·ha−1, two irrigation levels of 0.6-fold and 1.0-fold of the crop-pan coefficient, and two aeration treatments of 5 and 15 mg·L−1 for the three-factor and two-level completely randomized block experiment. The effects of soil dissolved-oxygen concentration, oxygen diffusion rate, soil respiration rate, soil urease, catalase, phosphatase activities and soil microbial biomass were systematically monitored and analyzed in the middle and at the end of crop growth. A structural equation model was used to comprehensively analyze the response relationship among relevant influencing factors. The results showed that coupled drip irrigation increased the soil’s dissolved oxygen, oxygen diffusion rate and soil respiration rate by 14.05%, 30.14% and 53.74%, respectively. Soil urease, catalase and phosphatase activities increased by 22.83%, 93.01% and 61.35%, respectively. The biomass of bacteria, fungi and actinomycetes increased by 49.06%, 50.18% and 20.39%, respectively. The results of a structural equation model analysis showed that water-fertilizer-air-coupling drip irrigation could effectively improve soil health status, and the descending order of influence was MB > EA > SA. This study provides scientific knowledge to reveal the improvement of soil health status by water-fertilizer-air-coupling drip irrigation.
Establishing the HPLC-MS/MS Method for Monitoring the Residue and Degradation of Butralin in Ginseng during Field and Risk Assessments
Authors: Wang Xiumei , You Qinghang , Hou Zhiguang , Yu Xiaolong , Gao Hemin , Gao Yuxue , Wang Liran , Wei Liping , Lu Zhongbin
Published: October 2022

Butralin can effectively mitigate the spreading of weeds in ginseng fields, however, the dissipation and residues of butralin in ginseng have not been investigated. In this study, we established a high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) method to determine the butralin residue and its dissipation in ginseng and its dietary intake risk. The mean recoveries of butralin in ginseng (fresh, dried, plants, and soil) ranged from 93.1–107.5% with relative standard deviations of 0.7–6.4%. The half-lives of butralin in ginseng plant and soil were 10.81–18.91 days, and its final residues in ginseng, dried gingeng, gingeng plant, and soil were <0.01, <0.010–0.02, 0.011–0.19, and 0.162–0.410 mg/kg, respectively. The dietary risk quotient of butralin was 3.25 × 10−4, which suggests that the consumption of butralin-treated ginseng during the harvest period does not affect human health.
Genetic Relationships and Diversity of Common Buckwheat Accessions in Bosnia and Herzegovina
Authors: Grahić Jasmin , Okić Arnela , Šimon Silvio , Djikić Mirha , Gadžo Drena , Pejić Ivan , Gaši Fuad
Published: October 2022

Common buckwheat (Fagopyrum esculentum Moench.) has a long history of cultivation in the large, mountainous regions of Bosnia and Herzegovina (B&H). Its commercial production is mainly based on the regionally bred variety ‘Darja’, but numerous landraces are also being grown on a smaller scale. As part of the SEEDNet (Southeast European Network on Plant Genetic Resources) project, these landraces have been collected and stored at the Gene bank of the Faculty of Agriculture and Food Sciences in Sarajevo (FAFS). To assess their utilization value, it was first important to investigate if they represent distinct landraces and to identify their genetic relationships with the most commonly grown varieties in the region (‘Darja’, ‘Goluba’ and ‘Čebelica’). Therefore, the aim of this study was to assess the genetic relationships and diversity of the common buckwheat accessions maintained at the FAFS Gene bank, as well as the value of these accessions for future breeding programs, using microsatellite markers and seventeen quantitative and fifteen qualitative morphological traits. The FCA (Factorial Correspondence Analysis) and AMOVA (Analysis of Molecular Variance) revealed that several accessions represent completely distinct landraces which clearly differentiated from the most commonly grown cultivars ‘Darja’ and ‘Goluba’. Conducted morphological analyses revealed that several of the analyzed landraces hold similar characteristics to the ones observed in ‘Darja’ and ‘Goluba’, while others possess unique traits potentially useful in breeding programs.
The Effect of Uncertainty of Risks on Farmers’ Contractual Choice Behavior for Agricultural Productive Services: An Empirical Analysis from the Black Soil in Northeast China
Authors: Xue Ying , Xu Yuxuan , Lyu Jie , Liu Hongbin
Published: October 2022

Regulating farmers’ choice of agricultural production service (APS) contracts can help maintain the stability of transactions, enhance agricultural production efficiency, protect farmers’ rights and welfare, stimulate the healthy and sustainable development of service organizations, and promote the economic benefits of agriculture. Under the uncertainty of risk (RU), farmers’ willingness to sign a regulated service contract after purchasing APS is a key factor in reaching an efficient and high-quality partnership. Based on the survey data of the black soil area in northeastern China, this study uses the Heckman two-stage model and analyzes it under the logical framework of APS purchases and contractual choice behavior (CCB) under the role of RU. The main findings are as follows. First, the RU has a significant “inducing” effect on farmers’ CCB, and the higher the RU, the more farmers tend to make formal written contracts; among them, each unit increase in business risk increases farmers’ choice of written contracts by 0.797 units, which is an important factor affecting CCB. Second, farmers’ personal trust level played a positive moderating role in influencing CCB. Compared to the low trust level group, farmers in the high trust level group had a diminished degree of influence on CCB, but the intensity was relatively weak. Third, farmers’ personal, family, and social characteristics all influence their behavioral decision-making processes. In order to reduce the risk level of cooperation between farmers and service providers, which can promote the standardization of cooperation contracts, this study suggests that the government should use the publication of manuals and other forms to carry out legal literacy, promote labor market information transparency, reduce service risks, and enhance the effectiveness of the linkage between farmers and service providers.