Pub Date : 2024-07-23DOI: 10.3390/agriculture14081209
Chengyao Jiang, Ke Xu, Jiahui Rao, Jiaming Liu, Yushan Li, Yu Song, Mengyao Li, Ya-Di Zheng, Wei Lu
An accurate gas utilization model is essential for precisely detecting plant photosynthetic capacity. Existing equipment for measuring the plant photosynthetic rate typically considers the key parameters of mesophyll cell conductance and a photosynthetic model based on the carbon reaction process under direct light conditions. However, the light environment signals received by the plant canopy not only vary significantly in incidence angles, but the effective light intensity also differs greatly from the measured values under vertical incidence conditions. To reduce the deviation between existing photosynthetic models and the actual photosynthetic efficiency of leaves, this study employs the gas diffusion method from engineering, using the finite element approach. Based on elastic mechanics and seepage mechanics, the internal stress field control equation of tomato leaves and the two-phase flow equation under a CO2 porous medium were derived. A mathematical model of porous gas–liquid two-phase fluid-solid coupling was established, solved, and analyzed. Preliminary verification was conducted through tests. The results show that in the initial stage of CO2 entering the leaf, the gas flow velocity is higher because of the larger pressure gradient between the pore and the leaf. In this stage, the gas diffusion rate is higher. As the intake time increases, the pressure gradient gradually decreases, and the inlet velocity slows down. Consequently, the diffusion rate gradually reduces. Because of the coupling of light quantity and light direction, the gas diffusion rate significantly increases compared with the uncoupled model. Additionally, a diffusion model that does not consider fluid–solid coupling will overestimate the gas flow rate as the depth of gas entry increases. Therefore, the internal gas diffusion model must account for the effect of coupling on the diffusion rate.
{"title":"Establishment and Solution of a Finite Element Gas Exchange Model in Greenhouse-Grown Tomatoes for Two-Dimensional Porous Media with Light Quantity and Light Direction","authors":"Chengyao Jiang, Ke Xu, Jiahui Rao, Jiaming Liu, Yushan Li, Yu Song, Mengyao Li, Ya-Di Zheng, Wei Lu","doi":"10.3390/agriculture14081209","DOIUrl":"https://doi.org/10.3390/agriculture14081209","url":null,"abstract":"An accurate gas utilization model is essential for precisely detecting plant photosynthetic capacity. Existing equipment for measuring the plant photosynthetic rate typically considers the key parameters of mesophyll cell conductance and a photosynthetic model based on the carbon reaction process under direct light conditions. However, the light environment signals received by the plant canopy not only vary significantly in incidence angles, but the effective light intensity also differs greatly from the measured values under vertical incidence conditions. To reduce the deviation between existing photosynthetic models and the actual photosynthetic efficiency of leaves, this study employs the gas diffusion method from engineering, using the finite element approach. Based on elastic mechanics and seepage mechanics, the internal stress field control equation of tomato leaves and the two-phase flow equation under a CO2 porous medium were derived. A mathematical model of porous gas–liquid two-phase fluid-solid coupling was established, solved, and analyzed. Preliminary verification was conducted through tests. The results show that in the initial stage of CO2 entering the leaf, the gas flow velocity is higher because of the larger pressure gradient between the pore and the leaf. In this stage, the gas diffusion rate is higher. As the intake time increases, the pressure gradient gradually decreases, and the inlet velocity slows down. Consequently, the diffusion rate gradually reduces. Because of the coupling of light quantity and light direction, the gas diffusion rate significantly increases compared with the uncoupled model. Additionally, a diffusion model that does not consider fluid–solid coupling will overestimate the gas flow rate as the depth of gas entry increases. Therefore, the internal gas diffusion model must account for the effect of coupling on the diffusion rate.","PeriodicalId":7447,"journal":{"name":"Agriculture","volume":"18 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141809937","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-23DOI: 10.3390/agriculture14081205
Daniele Caroline Hörz Engel, Daniela Feltrim, M. Rodrigues, J. L. C. Baptistella, Paulo Mazzafera
Protein hydrolysates are plant biostimulants containing amino acids, oligopeptides, and peptides in their composition. When supplied to plants, protein hydrolysates (HPs) have been identified to improve nitrogen metabolism, enhance the activity of antioxidant enzymes, boost plant defense response to stresses, and positively impact the quantity and quality of products. Soybean is a crucial global commodity, with nitrogen being the primary nutrient for crop development as it directly affects productivity. This study aimed to evaluate the effect of an HP-based biostimulant on the N metabolism in nodulated soybean plants and their productivity. A greenhouse experiment was conducted to test two modes of application of the 0.20% HP-based biostimulant. Soybean plants, growing in pots, were treated with 0.20% HP either via seed treatment or foliar application (at growth stages V3 and V5). Activities of enzymes and compounds related to N metabolism, gene expression, and productivity components were analyzed. It was observed that the mode of application did not significantly influence the results. The application of HPs increased the concentration of nitrate, amino acids, and ureides in soybean leaves. It also positively altered the expression of genes such as nitrate reductase, urease, and asparagine. Additionally, it enhanced productivity, resulting in plants with a greater number and weight of pods and grains. Therefore, it is possible to consider HPs as a stimulator for increasing soybean productivity, even under non-stressing conditions.
蛋白质水解物是一种植物生物刺激剂，其成分中含有氨基酸、寡肽和肽。蛋白质水解物（HPs）被认为可以改善植物的氮代谢，提高抗氧化酶的活性，增强植物对胁迫的防御能力，并对产品的数量和质量产生积极影响。大豆是一种重要的全球商品，氮是作物生长发育的主要养分，因为它直接影响生产率。本研究旨在评估一种基于 HP 的生物刺激剂对有节大豆植株的氮代谢及其生产力的影响。通过温室实验，测试了 0.20% HP 生物刺激剂的两种施用模式。盆栽大豆植株通过种子处理或叶面喷施（生长阶段 V3 和 V5）接受 0.20% HP 的处理。分析了与氮代谢有关的酶和化合物的活性、基因表达和生产力成分。结果表明，施用方式对结果影响不大。施用 HPs 增加了大豆叶片中硝酸盐、氨基酸和脲苷的浓度。它还积极改变了硝酸还原酶、脲酶和天冬酰胺等基因的表达。此外，它还能提高生产力，使植株结荚和结粒的数量和重量增加。因此，即使在非胁迫条件下，也可以将 HPs 视为提高大豆产量的刺激物。
{"title":"Application of Protein Hydrolysate Improved the Productivity of Soybean under Greenhouse Cultivation","authors":"Daniele Caroline Hörz Engel, Daniela Feltrim, M. Rodrigues, J. L. C. Baptistella, Paulo Mazzafera","doi":"10.3390/agriculture14081205","DOIUrl":"https://doi.org/10.3390/agriculture14081205","url":null,"abstract":"Protein hydrolysates are plant biostimulants containing amino acids, oligopeptides, and peptides in their composition. When supplied to plants, protein hydrolysates (HPs) have been identified to improve nitrogen metabolism, enhance the activity of antioxidant enzymes, boost plant defense response to stresses, and positively impact the quantity and quality of products. Soybean is a crucial global commodity, with nitrogen being the primary nutrient for crop development as it directly affects productivity. This study aimed to evaluate the effect of an HP-based biostimulant on the N metabolism in nodulated soybean plants and their productivity. A greenhouse experiment was conducted to test two modes of application of the 0.20% HP-based biostimulant. Soybean plants, growing in pots, were treated with 0.20% HP either via seed treatment or foliar application (at growth stages V3 and V5). Activities of enzymes and compounds related to N metabolism, gene expression, and productivity components were analyzed. It was observed that the mode of application did not significantly influence the results. The application of HPs increased the concentration of nitrate, amino acids, and ureides in soybean leaves. It also positively altered the expression of genes such as nitrate reductase, urease, and asparagine. Additionally, it enhanced productivity, resulting in plants with a greater number and weight of pods and grains. Therefore, it is possible to consider HPs as a stimulator for increasing soybean productivity, even under non-stressing conditions.","PeriodicalId":7447,"journal":{"name":"Agriculture","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141810500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-23DOI: 10.3390/agriculture14081208
Yanqin Huang, Huixian Shi, Erik Sindhøj, Guiyun Wang, Fuyuan Liu, Xingliang Gao, Huiying Du, Lianzhu Du, Keqiang Zhang
Dairy slurry could be a significant source of nitrogen (N) for plants, but mismanagement can lead to atmospheric ammonia losses or nitrate leaching into groundwater. To make the use of dairy slurry efficient and reasonable, the loss of N pollution to the environment should be reduced. We used repacked lysimeters to comprehensively determine ammonia emission and N leaching losses in an alfalfa–soil system. The application of dairy slurry had no significant effect on alfalfa yield at the same rate of N application in comparison to chemical fertilizer, and adding humic acids significantly increased yield by about 12%. However, the application of dairy slurry increased the ammonia emission rate significantly, leading to an increase in the cumulative amount of ammonia emission, while the addition of humic acids reduced the ammonia emissions by 11%. Chemical fertilizer and dairy slurry application significantly increased nitrate leaching compared to the control treatment, while the addition of humic acids can significantly reduce ammonium N leaching. Dairy slurry was proven to be as effective as chemical N fertilizer in achieving the optimum biomass, and adding humic acids can significantly reduce N loss to the atmosphere and groundwater. This study showed the possibility of replacing chemical fertilizer with dairy slurry in alfalfa production and the advantages of humic acids’ addition to alfalfa to maintain production yield and improve environmental friendliness.
{"title":"Humic Acids Combined with Dairy Slurry as Fertilizer Can Increase Alfalfa Yield and Reduce Nitrogen Losses","authors":"Yanqin Huang, Huixian Shi, Erik Sindhøj, Guiyun Wang, Fuyuan Liu, Xingliang Gao, Huiying Du, Lianzhu Du, Keqiang Zhang","doi":"10.3390/agriculture14081208","DOIUrl":"https://doi.org/10.3390/agriculture14081208","url":null,"abstract":"Dairy slurry could be a significant source of nitrogen (N) for plants, but mismanagement can lead to atmospheric ammonia losses or nitrate leaching into groundwater. To make the use of dairy slurry efficient and reasonable, the loss of N pollution to the environment should be reduced. We used repacked lysimeters to comprehensively determine ammonia emission and N leaching losses in an alfalfa–soil system. The application of dairy slurry had no significant effect on alfalfa yield at the same rate of N application in comparison to chemical fertilizer, and adding humic acids significantly increased yield by about 12%. However, the application of dairy slurry increased the ammonia emission rate significantly, leading to an increase in the cumulative amount of ammonia emission, while the addition of humic acids reduced the ammonia emissions by 11%. Chemical fertilizer and dairy slurry application significantly increased nitrate leaching compared to the control treatment, while the addition of humic acids can significantly reduce ammonium N leaching. Dairy slurry was proven to be as effective as chemical N fertilizer in achieving the optimum biomass, and adding humic acids can significantly reduce N loss to the atmosphere and groundwater. This study showed the possibility of replacing chemical fertilizer with dairy slurry in alfalfa production and the advantages of humic acids’ addition to alfalfa to maintain production yield and improve environmental friendliness.","PeriodicalId":7447,"journal":{"name":"Agriculture","volume":"21 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141813753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-22DOI: 10.3390/agriculture14071204
Michaela Heřmanová, Kateřina Kuralová, Michal Prokop, L. Pilař
This article addresses the pressing issue of attracting Generation Z to the agriculture sector in the Czech Republic, a vital issue given its crucial role in ensuring food security and sustainability. During demographic changes and declining interest from younger generations to work in agriculture, it is essential to understand and meet the specific needs of this generation. This article examines the alignment between advertised employee benefits and the preferences of Generation Z, offers a new employee benefits categorization, and highlights possible interventions to increase the attractiveness of the agricultural sector in the labor market. Based on a literature review, quantitative content analysis of job advertisements, and a questionnaire survey, the research aims to evaluate the current offers of employee benefits in the agricultural sector in the Czech Republic in terms of their attractiveness and how they are perceived by Generation Z before then categorizing these employee benefits. The results show that benefits from the “Holiday and times off” category have the highest value for Generation Z and that, on the contrary, they value benefits from the “Benefits for work–life balance” category the least. A total of seven categories of employee benefits have been newly identified.
本文探讨了捷克共和国农业部门吸引 Z 世代的紧迫问题，鉴于农业部门在确保粮食安全和可持续性方面的关键作用，这是一个至关重要的问题。在人口结构发生变化、年轻一代对农业工作的兴趣下降的情况下，了解并满足这一代人的特殊需求至关重要。本文探讨了广告宣传的员工福利与 Z 世代偏好之间的一致性，提供了一种新的员工福利分类，并强调了提高农业部门在劳动力市场中吸引力的可能干预措施。研究基于文献综述、招聘广告的定量内容分析和问卷调查，旨在评估捷克共和国农业部门目前提供的员工福利的吸引力以及 Z 世代对这些福利的看法，然后对这些员工福利进行分类。结果显示，"假期和休息时间 "类福利对 Z 世代的价值最高，相反，他们对 "平衡工作与生活的福利 "类福利的价值最低。新确定的员工福利共有七个类别。
{"title":"The Attractiveness of Employee Benefits in Agriculture from the Perspective of Generation Z","authors":"Michaela Heřmanová, Kateřina Kuralová, Michal Prokop, L. Pilař","doi":"10.3390/agriculture14071204","DOIUrl":"https://doi.org/10.3390/agriculture14071204","url":null,"abstract":"This article addresses the pressing issue of attracting Generation Z to the agriculture sector in the Czech Republic, a vital issue given its crucial role in ensuring food security and sustainability. During demographic changes and declining interest from younger generations to work in agriculture, it is essential to understand and meet the specific needs of this generation. This article examines the alignment between advertised employee benefits and the preferences of Generation Z, offers a new employee benefits categorization, and highlights possible interventions to increase the attractiveness of the agricultural sector in the labor market. Based on a literature review, quantitative content analysis of job advertisements, and a questionnaire survey, the research aims to evaluate the current offers of employee benefits in the agricultural sector in the Czech Republic in terms of their attractiveness and how they are perceived by Generation Z before then categorizing these employee benefits. The results show that benefits from the “Holiday and times off” category have the highest value for Generation Z and that, on the contrary, they value benefits from the “Benefits for work–life balance” category the least. A total of seven categories of employee benefits have been newly identified.","PeriodicalId":7447,"journal":{"name":"Agriculture","volume":"40 18","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141814899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-22DOI: 10.3390/agriculture14071202
Joao Paulo Costa, Vinicius Guimarães Nasser, W. R. Macedo, M. Santos, G. H. Silva
Increasing soybean productivity can be achieved by treating seeds with biostimulants. To this end, an investigation was conducted into the potential of a formulation prepared with clove es-sential oil (CEO) diluted in soybean oil for seed treatment. Soybean seeds were treated with CEO concentrations between 0.5 to 3.0 mL/L, and subjected to germination, vigor, and sanity analyses. The CEO at 1.6 mL/L exhibited favorable outcomes regarding germination, root length, and re-duced fungal infection. In this way, a two-crop field experiment evaluated soybean seeds treated with CEO at 1.6 mL/L. Soybean seeds treated with CEO in the field in 2021/2022 were not different from the controls. However, in 2019/2020, there was a higher percentage of emergence, nodulation, and production of 749 kg/ha more than in the industrial treatment. These results highlight the potential use of CEO as a biostimulant.
用生物刺激剂处理种子可以提高大豆的产量。为此，我们研究了用丁香精油（CEO）稀释在大豆油中配制的配方处理种子的潜力。用 0.5 至 3.0 mL/L 浓度的 CEO 处理大豆种子，并进行发芽率、活力和理智分析。浓度为 1.6 mL/L 的 CEO 在发芽率、根长和减少真菌感染方面表现出良好的效果。通过这种方法，一项两茬田间试验对使用 1.6 mL/L CEO 处理的大豆种子进行了评估。2021/2022 年在田间用 CEO 处理过的大豆种子与对照没有区别。然而，在 2019/2020 年，与工业处理相比，大豆种子的出苗率、拔节率更高，产量也增加了 749 公斤/公顷。这些结果凸显了 CEO 作为生物刺激剂的潜在用途。
{"title":"The Biostimulant Potential of Clove Essential Oil for Treating Soybean Seeds","authors":"Joao Paulo Costa, Vinicius Guimarães Nasser, W. R. Macedo, M. Santos, G. H. Silva","doi":"10.3390/agriculture14071202","DOIUrl":"https://doi.org/10.3390/agriculture14071202","url":null,"abstract":"Increasing soybean productivity can be achieved by treating seeds with biostimulants. To this end, an investigation was conducted into the potential of a formulation prepared with clove es-sential oil (CEO) diluted in soybean oil for seed treatment. Soybean seeds were treated with CEO concentrations between 0.5 to 3.0 mL/L, and subjected to germination, vigor, and sanity analyses. The CEO at 1.6 mL/L exhibited favorable outcomes regarding germination, root length, and re-duced fungal infection. In this way, a two-crop field experiment evaluated soybean seeds treated with CEO at 1.6 mL/L. Soybean seeds treated with CEO in the field in 2021/2022 were not different from the controls. However, in 2019/2020, there was a higher percentage of emergence, nodulation, and production of 749 kg/ha more than in the industrial treatment. These results highlight the potential use of CEO as a biostimulant.","PeriodicalId":7447,"journal":{"name":"Agriculture","volume":"21 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141814551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-22DOI: 10.3390/agriculture14071203
Peng Chen, Tianci Huang, Bei Wu, Huaiyuan Qian, Fangping Xie, Baohua Liu, Dawei Liu, Xu Li
Developing a flow rate model for the screw feeder and optimizing discharge performance are crucial for achieving automated intelligent precision feeding. This study constructs a mass flow rate model for screw conveyors, considering the coupled structural parameters of the hopper and screw conveyor. The model is developed using single-factor tests and central composite design (CCD) response surface tests and is validated through actual discharge tests. Results indicate that the discharge rate in the hopper–screw conveyor system is primarily influenced by the screw conveyor itself. Among the structural parameters, the hopper inclination angle and the hopper discharge opening length significantly affect the filling coefficient. Validation tests show an average error of 6.8% between the predicted and simulated mass flow rates and 5.0% with the actual mass flow rate, demonstrating the model’s high precision and accuracy.
{"title":"Modeling the Discharge Rate of a Screw Conveyor Considering Hopper–Conveyor Coupling Parameters","authors":"Peng Chen, Tianci Huang, Bei Wu, Huaiyuan Qian, Fangping Xie, Baohua Liu, Dawei Liu, Xu Li","doi":"10.3390/agriculture14071203","DOIUrl":"https://doi.org/10.3390/agriculture14071203","url":null,"abstract":"Developing a flow rate model for the screw feeder and optimizing discharge performance are crucial for achieving automated intelligent precision feeding. This study constructs a mass flow rate model for screw conveyors, considering the coupled structural parameters of the hopper and screw conveyor. The model is developed using single-factor tests and central composite design (CCD) response surface tests and is validated through actual discharge tests. Results indicate that the discharge rate in the hopper–screw conveyor system is primarily influenced by the screw conveyor itself. Among the structural parameters, the hopper inclination angle and the hopper discharge opening length significantly affect the filling coefficient. Validation tests show an average error of 6.8% between the predicted and simulated mass flow rates and 5.0% with the actual mass flow rate, demonstrating the model’s high precision and accuracy.","PeriodicalId":7447,"journal":{"name":"Agriculture","volume":"76 18","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141817845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-21DOI: 10.3390/agriculture14071199
Xuan Gu, Eiji Goto
Airflow plays a crucial role in plant growth because it supplies CO2, O2, and energy to plants in a plant factory with artificial light (PFAL). Therefore, understanding how various factors affect airflow in and around a plant canopy is essential. In this study, we developed a computational fluid dynamics (CFD) model with realistic plant structures created using structure-from-motion imaging to investigate airflow in and around a plant canopy. The averages of the absolute percentage errors of simulated air velocity in three conditions were 6.7%, 10.1%, 12.7%, respectively. The simulated and measured air velocities agreed well, confirming the accuracy of the developed CFD model. The effects of inflow velocities and plant canopy structures on the airflow in and around the plant canopy were analysed using the validated CFD model. The inflow velocities significantly decreased stagnant zones (from 62.4% to 7.2%) and increased the airflow uniformity in and around the plant canopy. A staggered layout of the plant canopy slightly decreased stagnant zones (from 16.4% to 13.2%) and increased the airflow uniformity. The airflow in and around the plant canopy was further inhibited by a large plant structure. This CFD model provided a basis for improving the airflow status in and around a plant canopy in a PFAL.
{"title":"Computational Fluid Dynamics Model with Realistic Plant Structures to Study Airflow in and around a Plant Canopy on a Cultivation Shelf in a Plant Factory with Artificial Light","authors":"Xuan Gu, Eiji Goto","doi":"10.3390/agriculture14071199","DOIUrl":"https://doi.org/10.3390/agriculture14071199","url":null,"abstract":"Airflow plays a crucial role in plant growth because it supplies CO2, O2, and energy to plants in a plant factory with artificial light (PFAL). Therefore, understanding how various factors affect airflow in and around a plant canopy is essential. In this study, we developed a computational fluid dynamics (CFD) model with realistic plant structures created using structure-from-motion imaging to investigate airflow in and around a plant canopy. The averages of the absolute percentage errors of simulated air velocity in three conditions were 6.7%, 10.1%, 12.7%, respectively. The simulated and measured air velocities agreed well, confirming the accuracy of the developed CFD model. The effects of inflow velocities and plant canopy structures on the airflow in and around the plant canopy were analysed using the validated CFD model. The inflow velocities significantly decreased stagnant zones (from 62.4% to 7.2%) and increased the airflow uniformity in and around the plant canopy. A staggered layout of the plant canopy slightly decreased stagnant zones (from 16.4% to 13.2%) and increased the airflow uniformity. The airflow in and around the plant canopy was further inhibited by a large plant structure. This CFD model provided a basis for improving the airflow status in and around a plant canopy in a PFAL.","PeriodicalId":7447,"journal":{"name":"Agriculture","volume":"54 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141817971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-21DOI: 10.3390/agriculture14071200
Kai Li, Haoyun Zhou, Jianhua Ren, Xiaozhen Liu, Zhuopeng Zhang
Hyperspectral technology is widely recognized as an effective method for monitoring soil salinity. However, the traditional sieved samples often cannot reflect the true condition of the soil surface. In particular, there is a lack of research on the spectral response of cracked salt-affected soils despite the common occurrence of cohesive saline soil shrinkage and cracking during water evaporation. To address this research, a laboratory was designed to simulate the desiccation cracking progress of 57 soda saline–alkali soil samples with different salinity levels in the Songnen Plain of China. After completion of the drying process, spectroscopic analysis was conducted on the surface of all the cracked soil samples. Moreover, this study aimed to evaluate the predictive ability of multiple linear regression models (MLR) for four main salt parameters. The hyperspectral reflectance data was analyzed using three different band screening methods, namely random forest (RF), principal component analysis (PCA), and Pearson correlation analysis (R). The findings revealed a significant correlation between desiccation cracking and soil salinity, suggesting that salinity is the primary factor influencing surface cracking of saline–alkali soil in the Songnen Plain. The results of the modeling analysis also indicated that, regardless of the spectral dimensionality reduction method employed, salinity exhibited the highest prediction accuracy for soil salinity, followed by electrical conductivity (EC) and sodium (Na+), while the pH model exhibited the weakest predictive performance. In addition, the usage of RF for band selection has the best effect compared with PCA and Pearson methods, which allows salt information of soda saline–alkali soils in Songnen Plain to be predicted precisely.
{"title":"A Comparative Study of Different Dimensionality Reduction Algorithms for Hyperspectral Prediction of Salt Information in Saline–Alkali Soils of Songnen Plain, China","authors":"Kai Li, Haoyun Zhou, Jianhua Ren, Xiaozhen Liu, Zhuopeng Zhang","doi":"10.3390/agriculture14071200","DOIUrl":"https://doi.org/10.3390/agriculture14071200","url":null,"abstract":"Hyperspectral technology is widely recognized as an effective method for monitoring soil salinity. However, the traditional sieved samples often cannot reflect the true condition of the soil surface. In particular, there is a lack of research on the spectral response of cracked salt-affected soils despite the common occurrence of cohesive saline soil shrinkage and cracking during water evaporation. To address this research, a laboratory was designed to simulate the desiccation cracking progress of 57 soda saline–alkali soil samples with different salinity levels in the Songnen Plain of China. After completion of the drying process, spectroscopic analysis was conducted on the surface of all the cracked soil samples. Moreover, this study aimed to evaluate the predictive ability of multiple linear regression models (MLR) for four main salt parameters. The hyperspectral reflectance data was analyzed using three different band screening methods, namely random forest (RF), principal component analysis (PCA), and Pearson correlation analysis (R). The findings revealed a significant correlation between desiccation cracking and soil salinity, suggesting that salinity is the primary factor influencing surface cracking of saline–alkali soil in the Songnen Plain. The results of the modeling analysis also indicated that, regardless of the spectral dimensionality reduction method employed, salinity exhibited the highest prediction accuracy for soil salinity, followed by electrical conductivity (EC) and sodium (Na+), while the pH model exhibited the weakest predictive performance. In addition, the usage of RF for band selection has the best effect compared with PCA and Pearson methods, which allows salt information of soda saline–alkali soils in Songnen Plain to be predicted precisely.","PeriodicalId":7447,"journal":{"name":"Agriculture","volume":"48 25","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141817994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-21DOI: 10.3390/agriculture14071198
Shaobin Zhang, Baofeng Shi
China is the largest soybean importer and consumer in the world. Soybean oil is the most-consumed vegetable oil in China, while soybean meal is the most important protein feed raw material in China, which affects the costs of animal husbandry. Volatility in the international soybean market would generate risk spillovers to China’s soybean industrial chain. This paper analyzed the channel of risk spillover from the international soybean market to China’s soybean industry chain and the asymmetry of the risk spillover. The degree of risk spillover from the international soybean market to the Chinese soybean industry chain was measured by the Copula–CoVaR model. The moderating role of inventory and demand in asymmetric risk spillovers was analyzed by quantile regression. We draw the following conclusions: First, the international soybean market impacts China’s soybean industry chain through soybeans rather than soybean meal and oil. The price fluctuation of China soybean market is obviously lower than that of the international soybean market. Second, there are apparent asymmetric risk spillovers from the international soybean market to China’s soybean industry chain, especially the soybean meal market. Third, increasing the Chinese soybean inventory and growing demand could effectively prevent the downside risk spillover from international markets to China’s soybean market. This also explains the asymmetry of risk spillovers. The research enriches the research perspective on food security, and the analysis of risk spillover mechanisms provides a scientific basis for relevant companies to develop risk-management strategies.
{"title":"The Asymmetric Tail Risk Spillover from the International Soybean Market to China’s Soybean Industry Chain","authors":"Shaobin Zhang, Baofeng Shi","doi":"10.3390/agriculture14071198","DOIUrl":"https://doi.org/10.3390/agriculture14071198","url":null,"abstract":"China is the largest soybean importer and consumer in the world. Soybean oil is the most-consumed vegetable oil in China, while soybean meal is the most important protein feed raw material in China, which affects the costs of animal husbandry. Volatility in the international soybean market would generate risk spillovers to China’s soybean industrial chain. This paper analyzed the channel of risk spillover from the international soybean market to China’s soybean industry chain and the asymmetry of the risk spillover. The degree of risk spillover from the international soybean market to the Chinese soybean industry chain was measured by the Copula–CoVaR model. The moderating role of inventory and demand in asymmetric risk spillovers was analyzed by quantile regression. We draw the following conclusions: First, the international soybean market impacts China’s soybean industry chain through soybeans rather than soybean meal and oil. The price fluctuation of China soybean market is obviously lower than that of the international soybean market. Second, there are apparent asymmetric risk spillovers from the international soybean market to China’s soybean industry chain, especially the soybean meal market. Third, increasing the Chinese soybean inventory and growing demand could effectively prevent the downside risk spillover from international markets to China’s soybean market. This also explains the asymmetry of risk spillovers. The research enriches the research perspective on food security, and the analysis of risk spillover mechanisms provides a scientific basis for relevant companies to develop risk-management strategies.","PeriodicalId":7447,"journal":{"name":"Agriculture","volume":"57 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141817925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-21DOI: 10.3390/agriculture14071201
Xiaohu Guo, Shiguo Wang, Shuren Chen, Bin Li, Zhong Tang, Yifan Hu
Inadequate parameter design of the cleaning device in soybean combine harvesters leads to elevated levels of machine harvesting losses and impurity rates. To provide fundamental data for the optimization of structural parameters of soybean cleaning sieves, it is of great significance to study the collision and bouncing characteristics of soybeans on the cleaning sieve surface and the impact of parameters on the coefficient of restitution (COR). The current study designed a collision platform, using soybeans at the harvest stage as the research subject. The experimental factors included drop height, wall inclination angle, wall movement speed, and wall material. Through single-factor experiments and orthogonal experiments, the effects of different collision parameters on the rebound trajectory and COR of soybeans were investigated. This study focuses on soybeans at the harvest stage as the test subjects. Experiments were conducted on a collision platform and recorded with a high-speed camera to capture the three-dimensional motion trajectories of the soybeans using the principle of specular reflection. Through single-factor experiments, the jumping characteristics of the soybeans on sieve surfaces with different motion characteristics were analyzed. The impact of drop height (400–650 mm), wall inclination angle (8–13°), wall movement speed (0.6–1.1 m/s), and wall material (stainless steel plates and polyurethane plates) on the coefficient of restitution (COR) was calculated and clarified. Multi-factor orthogonal experiments were conducted to determine the significance order of the different factors affecting the COR. Three-dimensional models of the soybeans and the collision platform were constructed using SolidWorks software, and the collision between the soybeans and the cleaning wall was simulated using EDEM software. The micro-forces and energy transfer during the soybean collision were analyzed. The results indicated that the COR of soybeans decreases as the drop height increases, but increases with wall inclination angle and wall movement speed. Additionally, the COR is higher when the soybeans collide with stainless steel plates compared to polyurethane plates. The order of influence of the four factors on the COR were: wall material > wall inclination angle > wall speed > drop height. This study provides important reference value for the efficient and low-loss design of cleaning devices.
{"title":"Impact of Structural Parameters on the Collision Characteristics and Coefficient of Restitution of Soybean Particles on Harvester’s Cleaning Screens","authors":"Xiaohu Guo, Shiguo Wang, Shuren Chen, Bin Li, Zhong Tang, Yifan Hu","doi":"10.3390/agriculture14071201","DOIUrl":"https://doi.org/10.3390/agriculture14071201","url":null,"abstract":"Inadequate parameter design of the cleaning device in soybean combine harvesters leads to elevated levels of machine harvesting losses and impurity rates. To provide fundamental data for the optimization of structural parameters of soybean cleaning sieves, it is of great significance to study the collision and bouncing characteristics of soybeans on the cleaning sieve surface and the impact of parameters on the coefficient of restitution (COR). The current study designed a collision platform, using soybeans at the harvest stage as the research subject. The experimental factors included drop height, wall inclination angle, wall movement speed, and wall material. Through single-factor experiments and orthogonal experiments, the effects of different collision parameters on the rebound trajectory and COR of soybeans were investigated. This study focuses on soybeans at the harvest stage as the test subjects. Experiments were conducted on a collision platform and recorded with a high-speed camera to capture the three-dimensional motion trajectories of the soybeans using the principle of specular reflection. Through single-factor experiments, the jumping characteristics of the soybeans on sieve surfaces with different motion characteristics were analyzed. The impact of drop height (400–650 mm), wall inclination angle (8–13°), wall movement speed (0.6–1.1 m/s), and wall material (stainless steel plates and polyurethane plates) on the coefficient of restitution (COR) was calculated and clarified. Multi-factor orthogonal experiments were conducted to determine the significance order of the different factors affecting the COR. Three-dimensional models of the soybeans and the collision platform were constructed using SolidWorks software, and the collision between the soybeans and the cleaning wall was simulated using EDEM software. The micro-forces and energy transfer during the soybean collision were analyzed. The results indicated that the COR of soybeans decreases as the drop height increases, but increases with wall inclination angle and wall movement speed. Additionally, the COR is higher when the soybeans collide with stainless steel plates compared to polyurethane plates. The order of influence of the four factors on the COR were: wall material > wall inclination angle > wall speed > drop height. This study provides important reference value for the efficient and low-loss design of cleaning devices.","PeriodicalId":7447,"journal":{"name":"Agriculture","volume":"94 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141818701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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