Highlights A commercial depth camera with a custom-designed graphical user interface was evaluated to detect tree canopy. Measurement variations under different indoor conditions were negligible for practical applications. Measurement errors ranged from 2.8% to 15.8%, which were acceptable for outdoor applications. Variation of crabapple canopy detection rate was less than 6% from sunrise to sunset. Abstract. To reduce crop protection product use and environmental impacts while maintaining application efficacy and convenience for applicators, an automatic variable rate sprayer coupled with a canopy detection sensor is required. A commercial depth camera was tested as a means of detecting the canopy of ornamental and tree crops for the sprayer. A custom-designed graphical user interface was developed to control the depth camera and save RGB and IR images and depth data to a local computer. Indoor evaluations showed that measurements could be influenced by the temperature and illumination; however, the influence was minimal, with a relative error of less than 1% and a maximum difference of 14 mm between the average measurements. The depth camera was able to detect a 31% to 72% area of a 20-mm wide target, and the rates went up 72% to 89% when the target width increased to 40 mm. The depth camera showed acceptable performance in detecting canopy contour changes and had measurement errors of 2.8% to 15.3% while detecting the distances to outdoor crabapple and oak trees. In addition, the depth camera detected tree canopy in various outdoor conditions from sunrise to sunset with reasonable accuracy (less than 10% of relative errors). In terms of measurement stability, the depth camera detected crabapple canopy with less than 6% variations under various illuminations between sunrise and sunset. The results suggested that the performance of the depth camera was adequate for detecting canopy under outdoor conditions for future variable-rate spray applications in ornamental and tree crop production. In addition, the study outlined the performance of the depth camera, which provided a guideline for future applications. Keywords: Machine Vision, Precision Agriculture, Specialty Crop, Stereo Vision, Variable Rate Application.
{"title":"Investigation of Depth Camera Potentials for Variable-Rate Sprayers","authors":"H. Jeon, Heping Zhu","doi":"10.13031/ja.15070","DOIUrl":"https://doi.org/10.13031/ja.15070","url":null,"abstract":"Highlights A commercial depth camera with a custom-designed graphical user interface was evaluated to detect tree canopy. Measurement variations under different indoor conditions were negligible for practical applications. Measurement errors ranged from 2.8% to 15.8%, which were acceptable for outdoor applications. Variation of crabapple canopy detection rate was less than 6% from sunrise to sunset. Abstract. To reduce crop protection product use and environmental impacts while maintaining application efficacy and convenience for applicators, an automatic variable rate sprayer coupled with a canopy detection sensor is required. A commercial depth camera was tested as a means of detecting the canopy of ornamental and tree crops for the sprayer. A custom-designed graphical user interface was developed to control the depth camera and save RGB and IR images and depth data to a local computer. Indoor evaluations showed that measurements could be influenced by the temperature and illumination; however, the influence was minimal, with a relative error of less than 1% and a maximum difference of 14 mm between the average measurements. The depth camera was able to detect a 31% to 72% area of a 20-mm wide target, and the rates went up 72% to 89% when the target width increased to 40 mm. The depth camera showed acceptable performance in detecting canopy contour changes and had measurement errors of 2.8% to 15.3% while detecting the distances to outdoor crabapple and oak trees. In addition, the depth camera detected tree canopy in various outdoor conditions from sunrise to sunset with reasonable accuracy (less than 10% of relative errors). In terms of measurement stability, the depth camera detected crabapple canopy with less than 6% variations under various illuminations between sunrise and sunset. The results suggested that the performance of the depth camera was adequate for detecting canopy under outdoor conditions for future variable-rate spray applications in ornamental and tree crop production. In addition, the study outlined the performance of the depth camera, which provided a guideline for future applications. Keywords: Machine Vision, Precision Agriculture, Specialty Crop, Stereo Vision, Variable Rate Application.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73820361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Highlights Fundamental engineering properties of hermetic bag liners were identified and measured to establish specifications for a new ASABE X657 standard for measurement and rating the performance of gas barrier liners in hermetic storage bags. Results showed strong evidence of differences in properties among six types of commercially available hermetic bag gas barrier liners (P<0.05). Critical gas barrier properties (OTR and WVTR) were measured to assess their ability to maintain initial conditions (“hermeticity”). Critical mechanical properties, such as impact failure weight, penetration resistance, and tear strength, were measured to determine their durability during handling and storage. Abstract. The impacts of hermetic storage bag technology on food security are well established. However, understanding the hermetic bag liner's mechanical and barrier properties with its useful life and efficacy are needed to ensure the continued successful adoption of this critically important storage technology to control biological activity. The goals of this study were to identify and quantify fundamental engineering properties as a basis for establishing an American Society of Agricultural and Biological Engineers (ASABE) engineering standard for testing and rating the hermeticity of gas barrier liners in storage bags for smallholder farmers. Six commercially available hermetic storage bag liners (AgroZ, Elite, PICS, GrainPro, Storezo, Zerofly) were evaluated for mechanical properties (tensile, impact, tear, penetration resistance) and barrier properties (oxygen transmission rate and water-vapor transmission rate) following American Society for Testing and Materials (ASTM) test methods. Results indicate significant differences (P< 0.05) in material properties among brands of storage bag liners. Values for oxygen and water vapor transmission rates were determined to ensure hermetic conditions can be achieved. Values for mechanical properties (yield and tensile strength, elongation, and toughness, tear strength, penetration resistance and impact failure weight) of gas barrier liners were quantified to ensure acceptable performance of hermetic storage bags. Keywords: Elongation, Hermetic storage, Hermetic storage bags, Impact failure weight, Oxygen Transmission Rates (OTR), Penetration resistance, Tear strength, Tensile strength, Toughness, Water Vapor Transmission Rate (WVTR), Yield strength.
{"title":"Engineering Properties of Commercially Available Hermetic Storage Bag Liners","authors":"M. Ignacio, D. Maier, K. Vorst","doi":"10.13031/ja.15366","DOIUrl":"https://doi.org/10.13031/ja.15366","url":null,"abstract":"Highlights Fundamental engineering properties of hermetic bag liners were identified and measured to establish specifications for a new ASABE X657 standard for measurement and rating the performance of gas barrier liners in hermetic storage bags. Results showed strong evidence of differences in properties among six types of commercially available hermetic bag gas barrier liners (P<0.05). Critical gas barrier properties (OTR and WVTR) were measured to assess their ability to maintain initial conditions (“hermeticity”). Critical mechanical properties, such as impact failure weight, penetration resistance, and tear strength, were measured to determine their durability during handling and storage. Abstract. The impacts of hermetic storage bag technology on food security are well established. However, understanding the hermetic bag liner's mechanical and barrier properties with its useful life and efficacy are needed to ensure the continued successful adoption of this critically important storage technology to control biological activity. The goals of this study were to identify and quantify fundamental engineering properties as a basis for establishing an American Society of Agricultural and Biological Engineers (ASABE) engineering standard for testing and rating the hermeticity of gas barrier liners in storage bags for smallholder farmers. Six commercially available hermetic storage bag liners (AgroZ, Elite, PICS, GrainPro, Storezo, Zerofly) were evaluated for mechanical properties (tensile, impact, tear, penetration resistance) and barrier properties (oxygen transmission rate and water-vapor transmission rate) following American Society for Testing and Materials (ASTM) test methods. Results indicate significant differences (P< 0.05) in material properties among brands of storage bag liners. Values for oxygen and water vapor transmission rates were determined to ensure hermetic conditions can be achieved. Values for mechanical properties (yield and tensile strength, elongation, and toughness, tear strength, penetration resistance and impact failure weight) of gas barrier liners were quantified to ensure acceptable performance of hermetic storage bags. Keywords: Elongation, Hermetic storage, Hermetic storage bags, Impact failure weight, Oxygen Transmission Rates (OTR), Penetration resistance, Tear strength, Tensile strength, Toughness, Water Vapor Transmission Rate (WVTR), Yield strength.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73871016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jizhong Wang, Yangchun Liu, Bo Zhao, Fengzhu Wang, Weipeng Zhang, Yang Li
Highlights Prevent metal foreign bodies from scratching the intestines of animals and damaging the harvest cutter. Highly integrated design of acquisition circuit. Application of electromagnetic simulation to verify the feasibility of the principle of eddy current effect. Establishment of Support Vector Machine Multi-Classification Algorithm Model. Abstract. Aiming at the problem that the metal foreign bodies mingled in the silage cause damage to the gastrointestinal tract of animals and livestock, as well as irreversible damage to the rotary cutter of the harvester, a metal foreign body detection and sensing device for the harvester feeding drum composed of multiple single coils and signal acquisition units was designed to realize real-time detection and alarm of metal foreign bodies during harvesting. The sensor adopted a monolithic design with high integration of the signal acquisition circuit, which has a strong anti-interference ability. First, the electromagnetic simulation model was established. According to the simulation analysis of the eddy current effect, when the metal foreign object enters the alternating magnetic field, the energy will be lost, and the equivalent impedance of the coil will change accordingly. Then, the existence of the metal foreign body can be determined by detecting the equivalent impedance Rp of the coil. Next, we adopted a support vector machine multi-classification algorithm to train the detection device. In this process, different sizes of metal (copper, aluminum, and iron) were used, which can effectively improve the sensitivity and accuracy of metal foreign body detection. Finally, the sensor was installed on the test stand for multi-scene simulation experiments. The results show that the metal detection sensor can quickly identify the existence of metal by detecting the equivalent impedance Rp based on the eddy current effect; at the same time, the size of this sensor for metal foreign body detection is limited to 0.6 mm in diameter, 12 mm in length, and 100 mm in maximum detecting distance. Keywords: Eddy current effect, Equivalent impedance, Harvester, Metal foreign body, Support vector machine.
{"title":"Design and Verification of Metal Foreign Body Detection Device for Harvester Based on Eddy Current Effect","authors":"Jizhong Wang, Yangchun Liu, Bo Zhao, Fengzhu Wang, Weipeng Zhang, Yang Li","doi":"10.13031/ja.15185","DOIUrl":"https://doi.org/10.13031/ja.15185","url":null,"abstract":"Highlights Prevent metal foreign bodies from scratching the intestines of animals and damaging the harvest cutter. Highly integrated design of acquisition circuit. Application of electromagnetic simulation to verify the feasibility of the principle of eddy current effect. Establishment of Support Vector Machine Multi-Classification Algorithm Model. Abstract. Aiming at the problem that the metal foreign bodies mingled in the silage cause damage to the gastrointestinal tract of animals and livestock, as well as irreversible damage to the rotary cutter of the harvester, a metal foreign body detection and sensing device for the harvester feeding drum composed of multiple single coils and signal acquisition units was designed to realize real-time detection and alarm of metal foreign bodies during harvesting. The sensor adopted a monolithic design with high integration of the signal acquisition circuit, which has a strong anti-interference ability. First, the electromagnetic simulation model was established. According to the simulation analysis of the eddy current effect, when the metal foreign object enters the alternating magnetic field, the energy will be lost, and the equivalent impedance of the coil will change accordingly. Then, the existence of the metal foreign body can be determined by detecting the equivalent impedance Rp of the coil. Next, we adopted a support vector machine multi-classification algorithm to train the detection device. In this process, different sizes of metal (copper, aluminum, and iron) were used, which can effectively improve the sensitivity and accuracy of metal foreign body detection. Finally, the sensor was installed on the test stand for multi-scene simulation experiments. The results show that the metal detection sensor can quickly identify the existence of metal by detecting the equivalent impedance Rp based on the eddy current effect; at the same time, the size of this sensor for metal foreign body detection is limited to 0.6 mm in diameter, 12 mm in length, and 100 mm in maximum detecting distance. Keywords: Eddy current effect, Equivalent impedance, Harvester, Metal foreign body, Support vector machine.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87146569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Or Bar-Shira1, Yosef Cohen, T. Shoshan, A. Bechar, A. Sadowsky, Yuval Cohen, S. Berman
Highlights Medjool date fruit bunches can be modeled in 3D based on structural decomposition and the use of Bezier curves. The 3D model can be used for generating artificial image datasets of Medjool fruit bunches. The annotated image datasets can be used to develop robust algorithms for robotic Medjool date thinning. Algorithms for determining the required thinning length are a prerequisite for Medjool date thinning automation. Abstract. Medjool is a premium date cultivar, and the market demands high-quality fruits, for which specific horticultural practices, including timely and efficient fruitlet thinning, are required. Currently, thinning the fruitlets is one of the most labor-intensive tasks in the Medjool cultivation cycle, and there is a need to develop methods for automating the thinning process. An algorithm determining the required thinning is a prerequisite for advancing toward thinning automation. An annotated Medjool fruit bunch image dataset is necessary for developing such an algorithm using state-of-the-art machine learning methods. Acquiring such a dataset is difficult and costly. The difficulty can be alleviated by using synthetic images. However, current methods for generating synthetic plant images are unsuitable for Medjool dates due to their geometrical features. The current work suggests a method for generating artificial images of Medjool fruit bunches from a 3D model based on structural decomposition into plant parts and the use of Bezier curves. Nineteen model variables and their distributions were defined for fruit bunch model generation. The models and synthetic images generated based on the models were verified by two plant physiologists who are experts in Medjool date cultivation. Fruit-bunch features were extracted from the generated images and used for learning the required remaining length of the spikelets after thinning using kernel estimation. The estimation was tested for images of two whorl-period combinations (Top-Early and Middle-Middle). The average scaled absolute estimation errors for both periods were very low (less than 1%).
{"title":"Artificial Medjool Date Fruit Bunch Image Synthesis: Towards Thinning Automation","authors":"Or Bar-Shira1, Yosef Cohen, T. Shoshan, A. Bechar, A. Sadowsky, Yuval Cohen, S. Berman","doi":"10.13031/ja.15217","DOIUrl":"https://doi.org/10.13031/ja.15217","url":null,"abstract":"Highlights Medjool date fruit bunches can be modeled in 3D based on structural decomposition and the use of Bezier curves. The 3D model can be used for generating artificial image datasets of Medjool fruit bunches. The annotated image datasets can be used to develop robust algorithms for robotic Medjool date thinning. Algorithms for determining the required thinning length are a prerequisite for Medjool date thinning automation. Abstract. Medjool is a premium date cultivar, and the market demands high-quality fruits, for which specific horticultural practices, including timely and efficient fruitlet thinning, are required. Currently, thinning the fruitlets is one of the most labor-intensive tasks in the Medjool cultivation cycle, and there is a need to develop methods for automating the thinning process. An algorithm determining the required thinning is a prerequisite for advancing toward thinning automation. An annotated Medjool fruit bunch image dataset is necessary for developing such an algorithm using state-of-the-art machine learning methods. Acquiring such a dataset is difficult and costly. The difficulty can be alleviated by using synthetic images. However, current methods for generating synthetic plant images are unsuitable for Medjool dates due to their geometrical features. The current work suggests a method for generating artificial images of Medjool fruit bunches from a 3D model based on structural decomposition into plant parts and the use of Bezier curves. Nineteen model variables and their distributions were defined for fruit bunch model generation. The models and synthetic images generated based on the models were verified by two plant physiologists who are experts in Medjool date cultivation. Fruit-bunch features were extracted from the generated images and used for learning the required remaining length of the spikelets after thinning using kernel estimation. The estimation was tested for images of two whorl-period combinations (Top-Early and Middle-Middle). The average scaled absolute estimation errors for both periods were very low (less than 1%).","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"175 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74159053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ankit Kumar Singh, Boris Bravo-Ureta, Richard McAvoy, Xiusheng Yang
Highlights We proposed to use GREENBOX technology for urban crop production in warehouse settings. We assessed the profitability of the application of GREENBOX technology using Benefit Cost Analysis (BCA) to evaluate the Net Present Value (NPV), Internal Rate of Return (IRR), and Payback Period (PP). We conducted sensitivity analyses on NPV, IRR, and PP over different scenarios. GREENBOX was found financially feasible for all the hypothetical scenarios in major cities in the USA. Abstract . Food security pressure, especially in urban areas, continues to rise due to surging demand for food resulting from a growing population and declining resources. It has been critical to improve crop production and make food readily available to consumers without traveling long distances in an economically sustainable manner. The novel GREENBOX technology uses Controlled Environment Agriculture (CEA) principles for leafy green crop production in urban structures. A GREENBOX is an individual thermally insulated chamber with an artificial lighting source and a soilless cultivation system (hydroponics) in an environment that is controlled at the grower's discretion. This study performed a financial feasibility study of GREENBOX technology for urban crop production in various scenarios to evaluate the system's profitability from an individual business's perspective and used market prices of the goods and services paid for or received by a project. The representative GREENBOX unit in the base case scenario had dimensions of a standard shipping pallet (1.0 x 1.2 x 0.9 m, or 40 x 48 x 36 in) and included thermally insulated walls, an LED artificial lighting source, a camera for monitoring growth, a Nutrient Film Technique (NFT) hydroponic growth platform, and an environmental monitoring and control system. A warehouse can host numerous GREENBOX units for mass production. We carried out a benefit-cost analysis by assessing the Net Present Value (NPV), Internal Rate of Return (IRR), and Payback Period (PP). These parameters were evaluated for a base case scenario from data collected or estimated for a representative GREENBOX unit. We also applied the base case scenario to investigate the financial performance of the GREENBOX setup in selected urban areas in the United States; New York City (New York), Miami (Florida), Los Angeles (California), Dallas (Texas), Atlanta (Georgia), Chicago (Illinois), Boston (Massachusetts), and Philadelphia (Pennsylvania). We then carried out a sensitivity analysis on NPV, IRR, and PP by keeping all the parameters in the base case scenario invariant except for one at a time. We obtained a summary equation to understand the variation of the financial parameters with changing lettuce sale price, electricity cost, rental cost, labor cost, and the number of GREENBOX units. A GREENBOX unit would require an initial investment of $398 to assemble and an annual outflow of $157 to cover operating expenses. GREENBOX cultivation was financially viable
我们建议将GREENBOX技术用于城市农作物的仓库生产。我们使用效益成本分析(BCA)来评估净现值(NPV)、内部收益率(IRR)和投资回收期(PP)，以评估应用GREENBOX技术的盈利能力。我们对不同情景下的NPV、IRR和PP进行了敏感性分析。GREENBOX在美国主要城市的所有假设场景中都是经济可行的。摘要由于人口增长和资源减少导致粮食需求激增，粮食安全压力，特别是城市地区的粮食安全压力继续上升。以经济上可持续的方式，在不长途跋涉的情况下，提高作物产量，使消费者随时可以获得食物，这一点至关重要。新型的GREENBOX技术采用了控制环境农业(CEA)原则，用于城市结构中的绿叶作物生产。GREENBOX是一个独立的隔热室，有人工光源和无土栽培系统(水培)，环境由种植者自行控制。本研究对GREENBOX技术在不同情况下用于城市作物生产的财务可行性进行了研究，从个体企业的角度评估该系统的盈利能力，并使用了项目支付或收到的商品和服务的市场价格。在基本情况下，典型的GREENBOX单元具有标准运输托盘的尺寸(1.0 x 1.2 x 0.9 m，或40 x 48 x 36英寸)，包括隔热墙，LED人工照明光源，用于监测生长的摄像机，营养膜技术(NFT)水培生长平台以及环境监测和控制系统。一个仓库可以容纳大量的GREENBOX单元进行大规模生产。我们通过评估净现值(NPV)、内部收益率(IRR)和投资回收期(PP)进行了收益-成本分析。这些参数是根据收集到的数据或为具有代表性的GREENBOX单元估计的基本情况进行评估的。我们还应用基本情景来调查GREENBOX设置在美国选定城市地区的财务绩效;纽约市(纽约州)、迈阿密(佛罗里达州)、洛杉矶(加利福尼亚州)、达拉斯(德克萨斯州)、亚特兰大(佐治亚州)、芝加哥(伊利诺伊州)、波士顿(马萨诸塞州)和费城(宾夕法尼亚州)。然后，我们对NPV、IRR和PP进行了敏感性分析，方法是保持基本情景中的所有参数不变，每次只保留一个参数。我们得到一个总结方程来理解财务参数随生菜销售价格、电费成本、租金成本、人工成本和GREENBOX单位数量的变化。一个GREENBOX单元需要初始投资398美元来组装，每年流出157美元来支付运营费用。在基本情景和所有研究的城市中，GREENBOX种植在财务上是可行的，具有不同程度的财务绩效。敏感性分析显示，除了熟练劳动力成本超过19美元/小时外，GREENBOX培养在所有情况下都是经济可行的，并且GREENBOX单位少于300个。推导出具有统计学意义的回归方程，其中租金成本、人工成本和电价的上升对NPV产生负向影响，而生菜销售价格和GREENBOX单位数量的上升对NPV产生正向影响。GREENBOX农业可以作为当地新鲜作物的来源，为城市消费者提供各种好处，包括改善食品安全，提高食品的新鲜度和营养，通过创造就业机会和销售收入为当地经济做出贡献，以及通过推广食品营养和生产计划提供教育机会。关键词:农业经营，环境控制，GREENBOX，生菜，都市农业
{"title":"GREENBOX Technology III - Financial Feasibility for Crop Production in Urban Settings","authors":"Ankit Kumar Singh, Boris Bravo-Ureta, Richard McAvoy, Xiusheng Yang","doi":"10.13031/ja.15345","DOIUrl":"https://doi.org/10.13031/ja.15345","url":null,"abstract":"Highlights We proposed to use GREENBOX technology for urban crop production in warehouse settings. We assessed the profitability of the application of GREENBOX technology using Benefit Cost Analysis (BCA) to evaluate the Net Present Value (NPV), Internal Rate of Return (IRR), and Payback Period (PP). We conducted sensitivity analyses on NPV, IRR, and PP over different scenarios. GREENBOX was found financially feasible for all the hypothetical scenarios in major cities in the USA. Abstract . Food security pressure, especially in urban areas, continues to rise due to surging demand for food resulting from a growing population and declining resources. It has been critical to improve crop production and make food readily available to consumers without traveling long distances in an economically sustainable manner. The novel GREENBOX technology uses Controlled Environment Agriculture (CEA) principles for leafy green crop production in urban structures. A GREENBOX is an individual thermally insulated chamber with an artificial lighting source and a soilless cultivation system (hydroponics) in an environment that is controlled at the grower's discretion. This study performed a financial feasibility study of GREENBOX technology for urban crop production in various scenarios to evaluate the system's profitability from an individual business's perspective and used market prices of the goods and services paid for or received by a project. The representative GREENBOX unit in the base case scenario had dimensions of a standard shipping pallet (1.0 x 1.2 x 0.9 m, or 40 x 48 x 36 in) and included thermally insulated walls, an LED artificial lighting source, a camera for monitoring growth, a Nutrient Film Technique (NFT) hydroponic growth platform, and an environmental monitoring and control system. A warehouse can host numerous GREENBOX units for mass production. We carried out a benefit-cost analysis by assessing the Net Present Value (NPV), Internal Rate of Return (IRR), and Payback Period (PP). These parameters were evaluated for a base case scenario from data collected or estimated for a representative GREENBOX unit. We also applied the base case scenario to investigate the financial performance of the GREENBOX setup in selected urban areas in the United States; New York City (New York), Miami (Florida), Los Angeles (California), Dallas (Texas), Atlanta (Georgia), Chicago (Illinois), Boston (Massachusetts), and Philadelphia (Pennsylvania). We then carried out a sensitivity analysis on NPV, IRR, and PP by keeping all the parameters in the base case scenario invariant except for one at a time. We obtained a summary equation to understand the variation of the financial parameters with changing lettuce sale price, electricity cost, rental cost, labor cost, and the number of GREENBOX units. A GREENBOX unit would require an initial investment of $398 to assemble and an annual outflow of $157 to cover operating expenses. GREENBOX cultivation was financially viable","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"2015 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135318290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ankit Kumar Singh, Richard McAvoy, Boris Bravo-Ureta, Xiusheng Yang
Highlights There are pressures on food security due to increasing population, demand, and urbanization. GREENBOX uses controlled environment agriculture for urban crop production in warehouse settings. GREENBOX provided the required environmental conditions and comparable biomass output year-round. GREENBOX is technically feasible for urban crop production. Abstract. The surging worldwide population and urbanization have increased food security and safety pressures. Therefore, there is a need to increase food production capacity in urban areas to feed this growing population. We have developed the GREENBOX technology to grow vegetables in individual climate-controlled boxes in urban warehouse environments. A GREENBOX is a thermally insulated modular structure of standard size with an artificial lighting source, a hydroponic nutrient supply system, and environmental controls. GREENBOX units can be used together in various numbers to form different configurations and production capacities. This study was conducted to evaluate the technical feasibility and performance of the GREENBOX technology for urban crop production in warehouse settings commonly found in urban areas. Two model GREENBOX units, constructed with commercially available parts, were located in a high-ceiling headhouse of a laboratory greenhouse complex at Storrs, Connecticut, USA, for the study. Forty-eight (48) heads of Butterhead Rex lettuce (Lactuca sativa) were grown in the model GREENBOX units (24 in each) over a 30-day growing cycle for four seasons. Environmental data, including light, temperature, relative humidity, and carbon dioxide, were collected using iPonic sensors at a frequency of every minute and processed to 15-minute averages. Crop growth was quantified with biomass data, which were wet weight, dry weight, total leaf area, and lettuce head area, using destructive and non-destructive methods every three days. A lysimeter was used to determine the water consumption rate by plants every fifteen minutes. We derived the Daily Light Integral (DLI), Leaf Area Index (LAI), Specific Leaf Area (SLA), productivity, and water consumed per lettuce head, per unit wet weight, and per unit dry weight. Descriptive statistics were used to describe and analyze the results. The DLI in the GREENBOX ranged between 32.48-37.23 mol/m2.d at the lettuce heads' height, higher than the recommended minimum DLI of 6.5-9.7 mol/m2.d. GREENBOX does not rely on external light but solely on the artificial lighting source, regulated at the grower's discretion. The mean temperatures inside were 24.5-26.9°C, falling within the optimal range of 17-29°C for lettuce. The artificial lighting source was a heat source to sustain cultivation. All year, the average relative humidity was 35.53%-58.54%, mostly within the ideal range of 40%-60%. The CO2 concentration inside the boxes fell slightly below the ambient concentration of 350 ppm, between 301.39 and 311.34 ppm over different seasons. Measured growth par
{"title":"GREENBOX Technology I - Technical Feasibility and Performance in Warehouse Environment","authors":"Ankit Kumar Singh, Richard McAvoy, Boris Bravo-Ureta, Xiusheng Yang","doi":"10.13031/ja.15343","DOIUrl":"https://doi.org/10.13031/ja.15343","url":null,"abstract":"Highlights There are pressures on food security due to increasing population, demand, and urbanization. GREENBOX uses controlled environment agriculture for urban crop production in warehouse settings. GREENBOX provided the required environmental conditions and comparable biomass output year-round. GREENBOX is technically feasible for urban crop production. Abstract. The surging worldwide population and urbanization have increased food security and safety pressures. Therefore, there is a need to increase food production capacity in urban areas to feed this growing population. We have developed the GREENBOX technology to grow vegetables in individual climate-controlled boxes in urban warehouse environments. A GREENBOX is a thermally insulated modular structure of standard size with an artificial lighting source, a hydroponic nutrient supply system, and environmental controls. GREENBOX units can be used together in various numbers to form different configurations and production capacities. This study was conducted to evaluate the technical feasibility and performance of the GREENBOX technology for urban crop production in warehouse settings commonly found in urban areas. Two model GREENBOX units, constructed with commercially available parts, were located in a high-ceiling headhouse of a laboratory greenhouse complex at Storrs, Connecticut, USA, for the study. Forty-eight (48) heads of Butterhead Rex lettuce (Lactuca sativa) were grown in the model GREENBOX units (24 in each) over a 30-day growing cycle for four seasons. Environmental data, including light, temperature, relative humidity, and carbon dioxide, were collected using iPonic sensors at a frequency of every minute and processed to 15-minute averages. Crop growth was quantified with biomass data, which were wet weight, dry weight, total leaf area, and lettuce head area, using destructive and non-destructive methods every three days. A lysimeter was used to determine the water consumption rate by plants every fifteen minutes. We derived the Daily Light Integral (DLI), Leaf Area Index (LAI), Specific Leaf Area (SLA), productivity, and water consumed per lettuce head, per unit wet weight, and per unit dry weight. Descriptive statistics were used to describe and analyze the results. The DLI in the GREENBOX ranged between 32.48-37.23 mol/m2.d at the lettuce heads' height, higher than the recommended minimum DLI of 6.5-9.7 mol/m2.d. GREENBOX does not rely on external light but solely on the artificial lighting source, regulated at the grower's discretion. The mean temperatures inside were 24.5-26.9°C, falling within the optimal range of 17-29°C for lettuce. The artificial lighting source was a heat source to sustain cultivation. All year, the average relative humidity was 35.53%-58.54%, mostly within the ideal range of 40%-60%. The CO2 concentration inside the boxes fell slightly below the ambient concentration of 350 ppm, between 301.39 and 311.34 ppm over different seasons. Measured growth par","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"250 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135601265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Feyereisen, E. Ghane, T. W. Schumacher, B. Dalzell, M. Williams
Highlights Novel three-bed, cascading-inlet bioreactor treated agricultural drainage from a 249-ha catchment. Nitrate removal rates and load reduction efficiencies were similar to those of traditional single-field bioreactors. Sedimentation problems reduced bed life; a sediment sensing and exclusion system solved them. This scale provides opportunities for centralized management and nutrient reduction verification. Abstract. Denitrifying bioreactors, a structural practice deployed at the field scale to meet water quality goals, have been underutilized and require additional evaluation at the small catchment scale. The objective of this study was to quantify the performance of a large, multi-bed denitrifying bioreactor system sized to treat agricultural drainage runoff (combined drainage discharge and surface runoff) from a 249-ha catchment. Three woodchip bioreactor beds, 7.6 m wide by 41 m long by 1.5 m deep, with cascading inlets, were constructed in 2016 in southern Minnesota, U.S. The beds received runoff for one water year from a catchment area that is 91% tile-drained row crops, primarily maize and soybeans. Initial woodchip quality differed among the three beds, affecting flow and nitrate removal rates. Bioreactor flow was unimpeded by sediment for twelve events from September 2016 to July 2017, during which time 55% of the discharge from the catchment was treated in the bioreactor beds. Average daily nitrate removal rates ranged from 2.5 to 6.5 g-N m-3 d-1 for the three bioreactor beds, with nitrate-N load removal of flow through the beds between 19% and 27%. When accounting for untreated by-pass flow, the overall nitrate-N removal of the multi-bed system was 12.5% (713 kg N). During high-flow events, incoming sediment clogged the reactor beds, decreasing their performance. There was 4,520 kg of sediment trapped in one bed, and evidence suggests the other two trapped a similar load. To solve this problem and prolong the bioreactor’s lifespan, we installed a shutoff gate that activated when inflow turbidity exceeded a threshold value. Finally, the findings indicate that catchment-scale denitrifying bioreactors can successfully remove nitrate load from agricultural runoff, but sediment-prevention measures may be required to extend the bioreactor's lifespan. Keywords: Bioreactor, Denitrification, Nitrate removal, Sedimentation, Subsurface drainage.
新型三床，梯级进水生物反应器处理249公顷集水区的农业污水。硝酸盐的去除率和负荷降低效率与传统的单场生物反应器相似。沉降问题降低了床层寿命;沉积物传感和排除系统解决了这些问题。该量表为集中管理和营养减少验证提供了机会。摘要反硝化生物反应器是在实地规模上为达到水质目标而部署的一种结构性做法，但尚未得到充分利用，需要在小集水区规模上进行额外评价。本研究的目的是量化大型多床反硝化生物反应器系统的性能，该系统用于处理249公顷集水区的农业排水径流(综合排水排放和地表径流)。2016年，美国明尼苏达州南部建造了三个木屑生物反应器床，宽7.6米，长41米，深1.5米，具有层叠式入口。这些床从集水区接收了一个水年的径流，该集水区91%是瓦片排水的行作物，主要是玉米和大豆。不同床层的初始木屑质量不同，影响了流速和硝酸盐去除率。在2016年9月至2017年7月的12个事件中，生物反应器的流动不受沉积物的阻碍，在此期间，55%的集水区排放在生物反应器床中进行处理。三个生物反应器床的平均每日硝酸盐去除率为2.5至6.5 g-N m-3 d-1，通过床的硝酸盐- n负荷去除率为19%至27%。考虑到未经处理的旁通流，多床系统的总体硝酸盐N去除率为12.5% (713 kg N)。在高流量事件期间，传入的沉积物堵塞了反应器床，降低了它们的性能。有4520公斤的沉积物被困在一个床上，证据表明其他两个床也有类似的负荷。为了解决这个问题并延长生物反应器的使用寿命，我们安装了一个关闭阀，当进水浊度超过阈值时就会启动。最后，研究结果表明，集水区规模的反硝化生物反应器可以成功地去除农业径流中的硝酸盐负荷，但可能需要采取防止沉积的措施来延长生物反应器的使用寿命。关键词:生物反应器，反硝化，硝酸盐去除，沉降，地下排水
{"title":"Can Woodchip Bioreactors Be Used at a Catchment Scale? Nitrate Performance and Sediment Considerations","authors":"G. Feyereisen, E. Ghane, T. W. Schumacher, B. Dalzell, M. Williams","doi":"10.13031/ja.15496","DOIUrl":"https://doi.org/10.13031/ja.15496","url":null,"abstract":"Highlights Novel three-bed, cascading-inlet bioreactor treated agricultural drainage from a 249-ha catchment. Nitrate removal rates and load reduction efficiencies were similar to those of traditional single-field bioreactors. Sedimentation problems reduced bed life; a sediment sensing and exclusion system solved them. This scale provides opportunities for centralized management and nutrient reduction verification. Abstract. Denitrifying bioreactors, a structural practice deployed at the field scale to meet water quality goals, have been underutilized and require additional evaluation at the small catchment scale. The objective of this study was to quantify the performance of a large, multi-bed denitrifying bioreactor system sized to treat agricultural drainage runoff (combined drainage discharge and surface runoff) from a 249-ha catchment. Three woodchip bioreactor beds, 7.6 m wide by 41 m long by 1.5 m deep, with cascading inlets, were constructed in 2016 in southern Minnesota, U.S. The beds received runoff for one water year from a catchment area that is 91% tile-drained row crops, primarily maize and soybeans. Initial woodchip quality differed among the three beds, affecting flow and nitrate removal rates. Bioreactor flow was unimpeded by sediment for twelve events from September 2016 to July 2017, during which time 55% of the discharge from the catchment was treated in the bioreactor beds. Average daily nitrate removal rates ranged from 2.5 to 6.5 g-N m-3 d-1 for the three bioreactor beds, with nitrate-N load removal of flow through the beds between 19% and 27%. When accounting for untreated by-pass flow, the overall nitrate-N removal of the multi-bed system was 12.5% (713 kg N). During high-flow events, incoming sediment clogged the reactor beds, decreasing their performance. There was 4,520 kg of sediment trapped in one bed, and evidence suggests the other two trapped a similar load. To solve this problem and prolong the bioreactor’s lifespan, we installed a shutoff gate that activated when inflow turbidity exceeded a threshold value. Finally, the findings indicate that catchment-scale denitrifying bioreactors can successfully remove nitrate load from agricultural runoff, but sediment-prevention measures may be required to extend the bioreactor's lifespan. Keywords: Bioreactor, Denitrification, Nitrate removal, Sedimentation, Subsurface drainage.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86312244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Highlights A one-stage reactor PN/A process was developed and evaluated. The highest TN removal rate was 87.3% for the PN/A process to treat synthetic wastewater containing poultry litter at room temperature. Bacterial composition of mature sludge community of wastewater was investigated in this study. Adjusted parameters controlled the growth of AOB and NOB. Abstract. Anammox is an increasingly common process used for the treatment of municipally rejected water and even mainstream wastewater due to its low oxygen demand. However, anammox is not commonly utilized in the treatment of poultry litter because of its high organic content, which would inhibit the anammox process. One-stage partial nitrification and anammox (PN/A) process was developed and evaluated for removing total nitrogen (TN) content from synthetic digestate of poultry litter using a sequencing batch biofilm reactor (SBBR). Independent variables including carbon to nitrogen ratio (C/N) at 1, 2, and 3, dissolved oxygen level (DO, mg/L) at 0.2, 0.35, and 0.5, and hydraulic retention time (HRT, h) at 24, 48, and 72 were examined using Central Composite Design (CCD) coupled with Response Surface Methodology (RSM) to optimize the TN removal rate. Results showed that the one-stage PN/A process achieved an optimal TN removal rate of 87.3% and an optimal NH4+-N removal rate of 100% when C/N, DO, and HRT were 1, 0.5 mg/L, and 72 h, respectively. The quadratic regression model developed (p = 0.0018) perfectly fitted the nitrogen removal efficiency of the SBBR. The uncertainty analysis showed an error range of 0.12% to 0.96% for the model's accuracy within the DO, C/N ratio, and HRT ranges tested. The bacterial consortium analysis suggested that the control of the growth of ammonium oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) was achieved. Keywords: Anammox, Comammox, Nitrospira, Partial nitrification, Poultry litter wastewater.
{"title":"Evaluation of the Combined C/N ratio, DO Set Point, and HRT Influence on Nitrogen Removal Rate in One-Stage Reactor Through Partial Nitrification Anammox Process During Treatment of Synthetic Digestate of Poultry Litter Wastewater","authors":"Yiting Xiao, Yuanhang Zhan, Jun Zhu, M. Vanotti","doi":"10.13031/ja.15019","DOIUrl":"https://doi.org/10.13031/ja.15019","url":null,"abstract":"Highlights A one-stage reactor PN/A process was developed and evaluated. The highest TN removal rate was 87.3% for the PN/A process to treat synthetic wastewater containing poultry litter at room temperature. Bacterial composition of mature sludge community of wastewater was investigated in this study. Adjusted parameters controlled the growth of AOB and NOB. Abstract. Anammox is an increasingly common process used for the treatment of municipally rejected water and even mainstream wastewater due to its low oxygen demand. However, anammox is not commonly utilized in the treatment of poultry litter because of its high organic content, which would inhibit the anammox process. One-stage partial nitrification and anammox (PN/A) process was developed and evaluated for removing total nitrogen (TN) content from synthetic digestate of poultry litter using a sequencing batch biofilm reactor (SBBR). Independent variables including carbon to nitrogen ratio (C/N) at 1, 2, and 3, dissolved oxygen level (DO, mg/L) at 0.2, 0.35, and 0.5, and hydraulic retention time (HRT, h) at 24, 48, and 72 were examined using Central Composite Design (CCD) coupled with Response Surface Methodology (RSM) to optimize the TN removal rate. Results showed that the one-stage PN/A process achieved an optimal TN removal rate of 87.3% and an optimal NH4+-N removal rate of 100% when C/N, DO, and HRT were 1, 0.5 mg/L, and 72 h, respectively. The quadratic regression model developed (p = 0.0018) perfectly fitted the nitrogen removal efficiency of the SBBR. The uncertainty analysis showed an error range of 0.12% to 0.96% for the model's accuracy within the DO, C/N ratio, and HRT ranges tested. The bacterial consortium analysis suggested that the control of the growth of ammonium oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) was achieved. Keywords: Anammox, Comammox, Nitrospira, Partial nitrification, Poultry litter wastewater.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"150 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79029057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. S. Kachout, S. Youssef, S. Khnissi, K. Guenni, A. Zoghlami, A. Ennajah, N. Ghorbel, J. Anchang, N. Hanan
Highlights Defoliation initiates physiological recovery and chemical defense mechanisms in Phalaris aquatica. Under infrequent defoliation treatment, P. aquatica has high DM production. Defoliation severity on herbage regrowth was associated with variation of secondary metabolite content and antioxidant activity. Phalaris may be suited to conservation pasture systems; the interval between cuts is about six weeks to maximize rates of regrowth. Results indicate that Phalaris may be used as fodder crop to sustained production and food security. Abstract. Perennial grasses are the key to the economic and environmental sustainability of pastures for livestock, and in arid and semi-arid environments, they can provide multiple ecosystem services more effectively than production systems based on annual crops. The objective of this study was to evaluate the effect of different defoliation frequencies on forage production and nutritive value of the Phalaris aquatica L. variety Soukra under field conditions in Tunis, Tunisia, over a period of 12 weeks. We tested four defoliation frequencies: (1) severe, (2) moderate, (3) infrequent, and (4) control. The growth responses measured were plant tiller number (NT), dry matter production (DM), and relative leaf regrowth rate (RLR). DM under the severe and moderate defoliation frequencies was 7% and 41% less than under control defoliation, respectively. However, DM production under infrequent defoliation was 91% and 43% higher than under severe and moderate defoliation. The relative leaf regrowth rate was affected by defoliation frequency; the highest regrowth rate was under severe treatment. However, tillering of P. aquatica was reduced under the severe and moderate frequencies of defoliation. Under increased defoliation frequencies, concentrations of secondary metabolites significantly decreased; total polyphenol content, flavonoid content, and tannin contents were higher in control and infrequent than in moderate and severe treatments. Antioxidant activity also decreased significantly with defoliation compared to the control treatment. There were no significant differences (P > 0.05) in ABTS (3-ethylbenzothiazoline-6-sulfonic acid) among the defoliation frequencies. Pearson's r correlation and PCA (Principal component analysis) data revealed that growth parameters, secondary metabolites, and antioxidant activity have positive and negative correlations in distinguishing the control and defoliation treatments. Results indicate that P. aquatica management should target moderate harvest rates in the adoption of perennial grass forage production systems in Tunisia. Use of perennial grasses for forage production can contribute to sustained production, food security, and rural livelihoods, and move farming systems towards providing multiple economic, environmental, and social benefits. Keywords: ABTS, Defoliation frequency, DPPH, Flavonoids, Growth responses, Matter production, Pe
{"title":"Growth Responses of the Perennial Grass, Phalaris Aquatica L., to Cutting Frequency and Influence on Secondary Metabolites and Antioxidant Activity","authors":"S. S. Kachout, S. Youssef, S. Khnissi, K. Guenni, A. Zoghlami, A. Ennajah, N. Ghorbel, J. Anchang, N. Hanan","doi":"10.13031/ja.15370","DOIUrl":"https://doi.org/10.13031/ja.15370","url":null,"abstract":"Highlights Defoliation initiates physiological recovery and chemical defense mechanisms in Phalaris aquatica. Under infrequent defoliation treatment, P. aquatica has high DM production. Defoliation severity on herbage regrowth was associated with variation of secondary metabolite content and antioxidant activity. Phalaris may be suited to conservation pasture systems; the interval between cuts is about six weeks to maximize rates of regrowth. Results indicate that Phalaris may be used as fodder crop to sustained production and food security. Abstract. Perennial grasses are the key to the economic and environmental sustainability of pastures for livestock, and in arid and semi-arid environments, they can provide multiple ecosystem services more effectively than production systems based on annual crops. The objective of this study was to evaluate the effect of different defoliation frequencies on forage production and nutritive value of the Phalaris aquatica L. variety Soukra under field conditions in Tunis, Tunisia, over a period of 12 weeks. We tested four defoliation frequencies: (1) severe, (2) moderate, (3) infrequent, and (4) control. The growth responses measured were plant tiller number (NT), dry matter production (DM), and relative leaf regrowth rate (RLR). DM under the severe and moderate defoliation frequencies was 7% and 41% less than under control defoliation, respectively. However, DM production under infrequent defoliation was 91% and 43% higher than under severe and moderate defoliation. The relative leaf regrowth rate was affected by defoliation frequency; the highest regrowth rate was under severe treatment. However, tillering of P. aquatica was reduced under the severe and moderate frequencies of defoliation. Under increased defoliation frequencies, concentrations of secondary metabolites significantly decreased; total polyphenol content, flavonoid content, and tannin contents were higher in control and infrequent than in moderate and severe treatments. Antioxidant activity also decreased significantly with defoliation compared to the control treatment. There were no significant differences (P > 0.05) in ABTS (3-ethylbenzothiazoline-6-sulfonic acid) among the defoliation frequencies. Pearson's r correlation and PCA (Principal component analysis) data revealed that growth parameters, secondary metabolites, and antioxidant activity have positive and negative correlations in distinguishing the control and defoliation treatments. Results indicate that P. aquatica management should target moderate harvest rates in the adoption of perennial grass forage production systems in Tunisia. Use of perennial grasses for forage production can contribute to sustained production, food security, and rural livelihoods, and move farming systems towards providing multiple economic, environmental, and social benefits. Keywords: ABTS, Defoliation frequency, DPPH, Flavonoids, Growth responses, Matter production, Pe","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"163 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77788761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chelsea Connair Clifford, Emily R. Waring, Carl H. Pederson, Matthew J. Helmers
Highlights Corn yields increased from 1989 to 2021 in Iowa experimental plots at nitrogen fertilizer rates consistently just above current recommendations. Increased corn yields did not result in a decrease in drainage nitrate exports. Findings required long-term (>10 years) experiments and monitoring. Abstract. Aquatic problems from the export of nutrients, especially nitrate, from row crops are recalcitrant in the Mississippi-Atchafalaya River Basin and globally severe. Previous studies have proposed to reduce these problems in part by improving crop yields, particularly corn, leaving less nitrate surplus to export. Simultaneous increases in fertilizer application rates and grain yields in recent decades have made testing this notion with large-scale agricultural statistics difficult. This experiment in Iowa featured a corn-soybean rotation with corn fertilized with nitrogen at a nearly consistent rate from 1989 to 2021. Corn yields increased at a rate not statistically distinguishable from the surrounding county’s (144 vs. 148 kg ha-1 yr-1), but drainage nitrate concentration and loading remained flat overall, oscillating with precipitation. Results suggest that increasing corn yield, and thereby partial factor productivity, with standard shifts in cultivars over time, cannot alone solve the U.S. Corn Belt’s nitrate surplus problem, supporting previous recommendations for active and multi-layered conservation efforts. Five- to ten-year positive and negative sub-trends in nitrate export within the longer dataset reaffirm the importance of truly long-term experiments and monitoring to accurately assess the impacts of management. Keywords: Keywords., Corn, Loading, Nitrate, Water quality, Yield.
{"title":"Corn Yield Increase Under Constant Fertilizer Did Not Reduce Nitrate Export","authors":"Chelsea Connair Clifford, Emily R. Waring, Carl H. Pederson, Matthew J. Helmers","doi":"10.13031/ja.15538","DOIUrl":"https://doi.org/10.13031/ja.15538","url":null,"abstract":"Highlights Corn yields increased from 1989 to 2021 in Iowa experimental plots at nitrogen fertilizer rates consistently just above current recommendations. Increased corn yields did not result in a decrease in drainage nitrate exports. Findings required long-term (&gt;10 years) experiments and monitoring. Abstract. Aquatic problems from the export of nutrients, especially nitrate, from row crops are recalcitrant in the Mississippi-Atchafalaya River Basin and globally severe. Previous studies have proposed to reduce these problems in part by improving crop yields, particularly corn, leaving less nitrate surplus to export. Simultaneous increases in fertilizer application rates and grain yields in recent decades have made testing this notion with large-scale agricultural statistics difficult. This experiment in Iowa featured a corn-soybean rotation with corn fertilized with nitrogen at a nearly consistent rate from 1989 to 2021. Corn yields increased at a rate not statistically distinguishable from the surrounding county’s (144 vs. 148 kg ha-1 yr-1), but drainage nitrate concentration and loading remained flat overall, oscillating with precipitation. Results suggest that increasing corn yield, and thereby partial factor productivity, with standard shifts in cultivars over time, cannot alone solve the U.S. Corn Belt’s nitrate surplus problem, supporting previous recommendations for active and multi-layered conservation efforts. Five- to ten-year positive and negative sub-trends in nitrate export within the longer dataset reaffirm the importance of truly long-term experiments and monitoring to accurately assess the impacts of management. Keywords: Keywords., Corn, Loading, Nitrate, Water quality, Yield.","PeriodicalId":29714,"journal":{"name":"Journal of the ASABE","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136003843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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