Dissolved reactive phosphorus (DRP) export from agricultural areas is a leading cause of nutrient pollution in freshwater systems (e.g., the North American Great Lakes). A potential solution to mitigate the excessive release of DRP is the use of nutrient management. To evaluate the effectiveness of nutrient management for phosphorus (P) in the United States, we conducted a review to synthesize P management and DRP export data from peer-reviewed articles published between 2000 to 2022. We identified 15 publications and extracted 113 and 90 observations from plot- and field-scale studies, respectively. At the plot scale, mean DRP concentrations were approximately 60% lower when P application rates were below the maximum recommended rate. In addition to the lower mean value, more extreme DRP export events occurred when the P fertilization rate was greater than the maximum recommended rate. In terms of application method, subsurface placement reduced mean DRP concentrations during rainfall simulations by 88% relative to surface placement (i.e., broadcasting). For fertilizer sources, mean DRP concentrations were similar between inorganic and organic fertilizers. However, at high application rates, organic fertilizers had a greater potential to produce extreme DRP export events. At the field-scale, organic fertilizers applied at high rates had the potential to produce extreme DRP export events. However, field-scale results for the other nutrient management techniques were generally inconclusive due to a limited number of studies and confounding factors. Overall, these results displayed the potential adverse impacts of overfertilization and the surface application of P fertilizers and highlighted the need for further research into the influence of nutrient management on P losses.
{"title":"Effectiveness of Nutrient Management for Reducing Phosphorus Losses from Agricultural Areas.","authors":"Brock Kamrath, Yongping Yuan","doi":"10.13031/jnrae.15572","DOIUrl":"10.13031/jnrae.15572","url":null,"abstract":"<p><p>Dissolved reactive phosphorus (DRP) export from agricultural areas is a leading cause of nutrient pollution in freshwater systems (e.g., the North American Great Lakes). A potential solution to mitigate the excessive release of DRP is the use of nutrient management. To evaluate the effectiveness of nutrient management for phosphorus (P) in the United States, we conducted a review to synthesize P management and DRP export data from peer-reviewed articles published between 2000 to 2022. We identified 15 publications and extracted 113 and 90 observations from plot- and field-scale studies, respectively. At the plot scale, mean DRP concentrations were approximately 60% lower when P application rates were below the maximum recommended rate. In addition to the lower mean value, more extreme DRP export events occurred when the P fertilization rate was greater than the maximum recommended rate. In terms of application method, subsurface placement reduced mean DRP concentrations during rainfall simulations by 88% relative to surface placement (i.e., broadcasting). For fertilizer sources, mean DRP concentrations were similar between inorganic and organic fertilizers. However, at high application rates, organic fertilizers had a greater potential to produce extreme DRP export events. At the field-scale, organic fertilizers applied at high rates had the potential to produce extreme DRP export events. However, field-scale results for the other nutrient management techniques were generally inconclusive due to a limited number of studies and confounding factors. Overall, these results displayed the potential adverse impacts of overfertilization and the surface application of P fertilizers and highlighted the need for further research into the influence of nutrient management on P losses.</p>","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"1 2","pages":"77-88"},"PeriodicalIF":1.4,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11238602/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141591464","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nutrient management, as described in NRCS Code 590, has been intensively investigated, with research largely focused on crop yields and water quality. Yet, due to complex processes and mechanisms in nutrient cycling (especially the nitrogen (N) cycle), there are many challenges in evaluating the effectiveness of nutrient management practices across site conditions. We therefore synthesized data from peer-reviewed publications on subsurface-drained agricultural fields in the Midwest U.S. with corn yield and drainage nitrate-N (NO3-N) export data published from 1980 to 2019. Through literature screening and data extraction from 43 publications, we obtained 577 site-years of data with detailed information on fertilization, corn yields, precipitation, drainage volume, and drainage NO3-N load/concentration or both. In addition, we estimated flow-weighted NO3-N concentrations ([NO3-N]) in drainage for those site-years where only load and volume were reported. Furthermore, we conducted a cost analysis using synthesized and surveyed corn yield data to evaluate the cost-effectiveness of different nutrient management plans. Results from the synthesis showed that N fertilizer rate was strongly positively correlated with corn yields, NO3-N loads, and flow-weighted [NO3-N]. Reducing N fertilizer rates can effectively mitigate NO3-N losses from agricultural fields; however, our cost analysis showed negative economic returns for continuous corn production at lower N rates. In addition, organic fertilizers significantly boosted corn yields and NO3-N losses compared to inorganic fertilizers at comparable rates; however, accurate quantification of plant-available N in organic fertilizers is necessary to guide appropriate nutrient management plans because the nutrient content may be highly variable. In terms of fertilizer application methods, we did not find significant differences in NO3-N export in drainage discharge. Lastly, impact of fertilization timing on NO3-N export varied depending on other factors such as fertilizer rate, source, and weather. According to these results, we suggest that further efforts are still required to produce effective local nutrient management plans. Furthermore, government agencies such as USDA-NRCS need to work with other agencies such as USEPA to address the potential economic losses due to implementation of lower fertilizer rates for water quality improvement.
{"title":"Effectiveness of Nutrient Management on Water Quality Improvement: A Synthesis on Nitrate-Nitrogen Loss from Subsurface Drainage.","authors":"W Liu, Y Yuan, L Koropeckyj-Cox","doi":"10.13031/trans.14078","DOIUrl":"https://doi.org/10.13031/trans.14078","url":null,"abstract":"<p><p>Nutrient management, as described in NRCS Code 590, has been intensively investigated, with research largely focused on crop yields and water quality. Yet, due to complex processes and mechanisms in nutrient cycling (especially the nitrogen (N) cycle), there are many challenges in evaluating the effectiveness of nutrient management practices across site conditions. We therefore synthesized data from peer-reviewed publications on subsurface-drained agricultural fields in the Midwest U.S. with corn yield and drainage nitrate-N (NO3-N) export data published from 1980 to 2019. Through literature screening and data extraction from 43 publications, we obtained 577 site-years of data with detailed information on fertilization, corn yields, precipitation, drainage volume, and drainage NO3-N load/concentration or both. In addition, we estimated flow-weighted NO3-N concentrations ([NO3-N]) in drainage for those site-years where only load and volume were reported. Furthermore, we conducted a cost analysis using synthesized and surveyed corn yield data to evaluate the cost-effectiveness of different nutrient management plans. Results from the synthesis showed that N fertilizer rate was strongly positively correlated with corn yields, NO3-N loads, and flow-weighted [NO3-N]. Reducing N fertilizer rates can effectively mitigate NO3-N losses from agricultural fields; however, our cost analysis showed negative economic returns for continuous corn production at lower N rates. In addition, organic fertilizers significantly boosted corn yields and NO3-N losses compared to inorganic fertilizers at comparable rates; however, accurate quantification of plant-available N in organic fertilizers is necessary to guide appropriate nutrient management plans because the nutrient content may be highly variable. In terms of fertilizer application methods, we did not find significant differences in NO3-N export in drainage discharge. Lastly, impact of fertilization timing on NO3-N export varied depending on other factors such as fertilizer rate, source, and weather. According to these results, we suggest that further efforts are still required to produce effective local nutrient management plans. Furthermore, government agencies such as USDA-NRCS need to work with other agencies such as USEPA to address the potential economic losses due to implementation of lower fertilizer rates for water quality improvement.</p>","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"64 2","pages":"675-689"},"PeriodicalIF":1.5,"publicationDate":"2021-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.13031/trans.14078","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39266427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tyler J. Barzee, Abdolhossein Edalati, Joshua Rapport, H. El-mashad, Ruihong Zhang
HighlightsN, P, Ca, and Mg were mainly localized to fine digestate solids (0.45 µm to 1 mm).50% to 60% of NH4+-N was found in digestate solids between 0.45 and 75 µm.K and Na were mainly transferred to the ultrafiltration permeate (<0.45 µm).Mixing of coarse and fine solids can optimize nutrient and salt ratios in products.Abstract. Food waste and dairy manure digestates from commercial digesters were characterized in the lab for particle and nutrient distributions before pilot-scale processing (vibratory screen, ultrafiltration, sun drying) to produce solid and liquid biofertilizer products. Experimental results showed that the elemental compositions of the two digestates were different but shared similarities. The coarse solids of both digestates had lower concentrations of nutrients than the liquid fractions, which contained most of the K and Na. The dairy manure digestate had a higher amount of fine solids between 0.4 and 75 µm than the food waste digestate, but the majority of TKN was contained in the fine solids of both digestates. An optimization analysis concluded that optimal combinations of digestate fractions included over 70% coarse solids to obtain desired nutrient and salt ratios. The solid and liquid fertilizer products derived from the pilot-scale processing were similar to those expected from the lab-scale investigation. Keywords: Biofertilizer formulation, Digestate, Nutrient distribution, Pilot-scale processing, Ultrafiltration, Value-added products.
n, P, Ca和Mg主要定位于细消化固体(0.45µm至1 mm)。50% ~ 60%的NH4+-N存在于0.45 ~ 75µm的消化固体中。K和Na主要转移到超滤渗透膜(<0.45µm)。粗、细固体混合可优化产品中营养和盐的比例。在中试规模处理(振动筛、超滤、晒干)生产固体和液体生物肥料产品之前，在实验室对商业消化器消化的食物垃圾和奶牛粪便进行了颗粒和营养分布的表征。实验结果表明，两种消化液的元素组成不同，但有相似之处。两种消化液的粗固体组分的营养物质浓度都低于含有大部分钾和钠的液体组分。乳肥消化液中0.4 ~ 75µm的细固体含量高于餐厨垃圾消化液，但TKN主要存在于两种消化液的细固体中。优化分析表明，消化物组分的最佳组合包括70%以上的粗固体，以获得理想的营养和盐比。从中试规模加工中获得的固体和液体肥料产品与实验室规模调查的预期产品相似。关键词:生物肥料配方，消化，养分分配，中试处理，超滤，增值产品
{"title":"Characterization of Nutrients and Pilot Biofertilizer Production from Food Waste and Dairy Manure Digestates","authors":"Tyler J. Barzee, Abdolhossein Edalati, Joshua Rapport, H. El-mashad, Ruihong Zhang","doi":"10.13031/trans.13767","DOIUrl":"https://doi.org/10.13031/trans.13767","url":null,"abstract":"HighlightsN, P, Ca, and Mg were mainly localized to fine digestate solids (0.45 µm to 1 mm).50% to 60% of NH4+-N was found in digestate solids between 0.45 and 75 µm.K and Na were mainly transferred to the ultrafiltration permeate (<0.45 µm).Mixing of coarse and fine solids can optimize nutrient and salt ratios in products.Abstract. Food waste and dairy manure digestates from commercial digesters were characterized in the lab for particle and nutrient distributions before pilot-scale processing (vibratory screen, ultrafiltration, sun drying) to produce solid and liquid biofertilizer products. Experimental results showed that the elemental compositions of the two digestates were different but shared similarities. The coarse solids of both digestates had lower concentrations of nutrients than the liquid fractions, which contained most of the K and Na. The dairy manure digestate had a higher amount of fine solids between 0.4 and 75 µm than the food waste digestate, but the majority of TKN was contained in the fine solids of both digestates. An optimization analysis concluded that optimal combinations of digestate fractions included over 70% coarse solids to obtain desired nutrient and salt ratios. The solid and liquid fertilizer products derived from the pilot-scale processing were similar to those expected from the lab-scale investigation. Keywords: Biofertilizer formulation, Digestate, Nutrient distribution, Pilot-scale processing, Ultrafiltration, Value-added products.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"5 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72591813","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}
Wu Cui, Wang Zhen, Hui Wu, Zhan Lu, Cheng Qian, Shunru Jin, Wang Rui, Youqing Meng, Jian Wu, Jianfeng Ping, Y. Ying, Z. Ye
HighlightsA portable system based on real-time fluorescence analysis was developed for field detection of Candidatus Liberibacter asiaticus within 40 min from sample to answer.A smartphone-assisted device was designed for easy operation, reliable nucleic acid amplification, and highly sensitive fluorescence detection, with sensitivity comparable to that of a commercial instrument.A novel homemade 3D printed box was used for in-field reagent storage, and it could maintain low temperature (<4°C) for about 8 hours without power supply.This fully integrated system is stable, easy to use, inexpensive, and has great application prospects in resource-limited areas.Abstract. Candidatus Liberibacter asiaticus (Las) is a main causal agent of huanglongbing (HLB), a destructive disease that has greatly reduced citrus yields and quality. Instruments with high sensitivity and portability are urgently required for on-site testing. In this study, a novel sample-to-answer optical system for on-site detection of Las was developed. Three major functions, including DNA extraction, amplification, and detection, are integrated into a portable case. This system mainly consists of (1) a specially designed 3D printed box for on-site reagent storage that can maintain low temperature (below 4°C) for 7.5 h at ambient temperature (35°C); (2) a custom device, called the IF-Device, for DNA amplification and detection of HLB, with an optimized optical structure, a sensitive signal processing circuit, and a precise temperature control algorithm with an accuracy of ±0.1°C; and (3) a battery-based power supply for the whole system. In a typical test using sodium fluorescein as a standard model, the results showed that the sensitivity of this system (1.0 nM) could easily meet the requirements of fluorescence biosensors. The feasibility of this homemade system was evaluated with samples extracted from infected citrus leaves based on the loop-mediated isothermal amplification (LAMP) method, and the limit of detection (LOD) was approximately 1.0 × 10-4 ng µL-1. The whole detection process for eight samples could be simultaneously accomplished within 40 min, and the results could be displayed on a smartphone in real-time. Moreover, the portable case is anti-interference, low cost, and only 2 kg in weight. Considering its sensitivity, stability, and portability, this highly integrated system possesses promising prospects for in-field detection. Keywords: Field detection, Fluorescence biosensor, Huanglongbing, Isothermal amplification, Sample-to-answer.
{"title":"A Sample-to-Answer Compact Optical System for On-Site Detection of Candidatus Liberibacter Asiaticus","authors":"Wu Cui, Wang Zhen, Hui Wu, Zhan Lu, Cheng Qian, Shunru Jin, Wang Rui, Youqing Meng, Jian Wu, Jianfeng Ping, Y. Ying, Z. Ye","doi":"10.13031/trans.13937","DOIUrl":"https://doi.org/10.13031/trans.13937","url":null,"abstract":"HighlightsA portable system based on real-time fluorescence analysis was developed for field detection of Candidatus Liberibacter asiaticus within 40 min from sample to answer.A smartphone-assisted device was designed for easy operation, reliable nucleic acid amplification, and highly sensitive fluorescence detection, with sensitivity comparable to that of a commercial instrument.A novel homemade 3D printed box was used for in-field reagent storage, and it could maintain low temperature (<4°C) for about 8 hours without power supply.This fully integrated system is stable, easy to use, inexpensive, and has great application prospects in resource-limited areas.Abstract. Candidatus Liberibacter asiaticus (Las) is a main causal agent of huanglongbing (HLB), a destructive disease that has greatly reduced citrus yields and quality. Instruments with high sensitivity and portability are urgently required for on-site testing. In this study, a novel sample-to-answer optical system for on-site detection of Las was developed. Three major functions, including DNA extraction, amplification, and detection, are integrated into a portable case. This system mainly consists of (1) a specially designed 3D printed box for on-site reagent storage that can maintain low temperature (below 4°C) for 7.5 h at ambient temperature (35°C); (2) a custom device, called the IF-Device, for DNA amplification and detection of HLB, with an optimized optical structure, a sensitive signal processing circuit, and a precise temperature control algorithm with an accuracy of ±0.1°C; and (3) a battery-based power supply for the whole system. In a typical test using sodium fluorescein as a standard model, the results showed that the sensitivity of this system (1.0 nM) could easily meet the requirements of fluorescence biosensors. The feasibility of this homemade system was evaluated with samples extracted from infected citrus leaves based on the loop-mediated isothermal amplification (LAMP) method, and the limit of detection (LOD) was approximately 1.0 × 10-4 ng µL-1. The whole detection process for eight samples could be simultaneously accomplished within 40 min, and the results could be displayed on a smartphone in real-time. Moreover, the portable case is anti-interference, low cost, and only 2 kg in weight. Considering its sensitivity, stability, and portability, this highly integrated system possesses promising prospects for in-field detection. Keywords: Field detection, Fluorescence biosensor, Huanglongbing, Isothermal amplification, Sample-to-answer.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"8 1","pages":"95-102"},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77722363","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}
Rongyan Wang, Zhian Zheng, Lei Gao, A. Chen, Shanyu Wang, Yiyao Xu
HighlightsA practical cam disc comb-type chrysanthemum picking machine was developed.A three-dimensional model of the picking machine was designed in SolidWorks.The working principle and motion trajectory of the picking comb teeth were analyzed.The best working parameters of the picking machine were obtained with field tests.Abstract. Aiming at the problems of labor, picking efficiency, and mechanization, a small practical cam disc comb-type chrysanthemum picking machine was designed. The picking machine, mainly composed of a wheeled frame, power transmission system, cam disc, picking comb, and cleaning comb sleeve, uses the pulling force of comb teeth to pick chrysanthemum flowers. The comb teeth rotate on a central shaft, and their swing angle is determined by a groove on the cam disc. One rotation of the comb teeth completes the process of picking, lifting, and unloading. In this study, the parameters of the cam profile were designed using an analytical method. To ensure reliability of the components, the trajectory of the comb teeth and their structure and motion parameters were analyzed, and the conditions for picking chrysanthemums were determined. The physical parameters of chrysanthemum plants were measured, and a prototype picking machine was built. Field tests were conducted using the comb rotational speed, comb teeth spacing, and comb working depth as the test factors and the picking rate, impurity rate, breakage rate, and drop rate as the evaluation indexes. The effects of each factor and the interaction of any two factors on the picking effectiveness were obtained. The test results suggested that the most effective harvesting was achieved when the comb rotational speed was 40 rpm, the comb teeth spacing was 8 mm, and the comb working depth was 200 mm. With these parameters, the picking rate was 93.28%, the breakage rate was 1.21%, the impurity rate was 8.38%, and the drop rate was 6.61%. The prototype machine achieved good picking effectiveness, and this study provides a technical foundation for the realization of mechanized chrysanthemum harvesting. Keywords: Cam, Chrysanthemum, Comb teeth, Motion track, Picking machine.
{"title":"Development and Testing of a Cam Disc Comb-Type Picking Machine for Chrysanthemum (Dendranthema morifolium Ramat. Tzvelev)","authors":"Rongyan Wang, Zhian Zheng, Lei Gao, A. Chen, Shanyu Wang, Yiyao Xu","doi":"10.13031/trans.14347","DOIUrl":"https://doi.org/10.13031/trans.14347","url":null,"abstract":"HighlightsA practical cam disc comb-type chrysanthemum picking machine was developed.A three-dimensional model of the picking machine was designed in SolidWorks.The working principle and motion trajectory of the picking comb teeth were analyzed.The best working parameters of the picking machine were obtained with field tests.Abstract. Aiming at the problems of labor, picking efficiency, and mechanization, a small practical cam disc comb-type chrysanthemum picking machine was designed. The picking machine, mainly composed of a wheeled frame, power transmission system, cam disc, picking comb, and cleaning comb sleeve, uses the pulling force of comb teeth to pick chrysanthemum flowers. The comb teeth rotate on a central shaft, and their swing angle is determined by a groove on the cam disc. One rotation of the comb teeth completes the process of picking, lifting, and unloading. In this study, the parameters of the cam profile were designed using an analytical method. To ensure reliability of the components, the trajectory of the comb teeth and their structure and motion parameters were analyzed, and the conditions for picking chrysanthemums were determined. The physical parameters of chrysanthemum plants were measured, and a prototype picking machine was built. Field tests were conducted using the comb rotational speed, comb teeth spacing, and comb working depth as the test factors and the picking rate, impurity rate, breakage rate, and drop rate as the evaluation indexes. The effects of each factor and the interaction of any two factors on the picking effectiveness were obtained. The test results suggested that the most effective harvesting was achieved when the comb rotational speed was 40 rpm, the comb teeth spacing was 8 mm, and the comb working depth was 200 mm. With these parameters, the picking rate was 93.28%, the breakage rate was 1.21%, the impurity rate was 8.38%, and the drop rate was 6.61%. The prototype machine achieved good picking effectiveness, and this study provides a technical foundation for the realization of mechanized chrysanthemum harvesting. Keywords: Cam, Chrysanthemum, Comb teeth, Motion track, Picking machine.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"131 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79618420","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}
HighlightsA handheld device was developed for automatic on-site measurement of fruit firmness.The prototype device achieved better performance than a typical commercial penetrometer.Two commonly used firmness-related parameters could be predicted based on the prototype readings.The distribution and changes of firmness could be visualized based on 3D models of the prototype readings.Abstract. Firmness is an important indicator of fruit quality. The devices for on-site fruit firmness measurement need to be portable, low-cost, lightweight, reliable, and flexible. Existing portable devices can provide firmness-related parameters, but their measurement results cannot be converted to each other. Their measurement results are also susceptible to operator error due to the manual measurement process. To solve this problem, a prototype handheld device was developed based on sensing fruit resistance to achieve automatic on-site firmness measurement of fruit with edible peel and provide commonly used firmness-related parameters. The prototype’s precision was verified by analyzing the repeatability and reproducibility of the measurement results with four Shore hardness blocks. The relative standard deviations (RSDs) of the results obtained by the same operator were less than 0.61%, and there was no significant difference among the results obtained by different operators (p < 0.05), which indicated that the prototype could provide reliable measurement results. A case study of peaches was performed, and the results showed that (1) the prototype had better performance than a commercial penetrometer, (2) two commonly used firmness-related parameters could be predicted based on regression models between a texture analyzer and the prototype readings (R2P = 0.908 and RMSEP = 4.191 N for maximum force; R2P = 0.923 and RMSEP = 1.613 N mm-1 for initial slope), (3) changes in the prototype readings for peaches during growth corresponded with the growth characteristics, and (4) the distribution and changes of peach firmness over time could be visualized based on 3D models of the prototype readings. Keywords: Automatic, Fruit firmness, Handheld device, High precision, Peach.
{"title":"An Automatic Handheld Device for Firmness Measurement of Fruit with Edible Peel Based on Resistance Sensing: A Case Study of Peaches","authors":"Dachen Wang, Zhe Feng, Di Cui","doi":"10.13031/trans.14656","DOIUrl":"https://doi.org/10.13031/trans.14656","url":null,"abstract":"HighlightsA handheld device was developed for automatic on-site measurement of fruit firmness.The prototype device achieved better performance than a typical commercial penetrometer.Two commonly used firmness-related parameters could be predicted based on the prototype readings.The distribution and changes of firmness could be visualized based on 3D models of the prototype readings.Abstract. Firmness is an important indicator of fruit quality. The devices for on-site fruit firmness measurement need to be portable, low-cost, lightweight, reliable, and flexible. Existing portable devices can provide firmness-related parameters, but their measurement results cannot be converted to each other. Their measurement results are also susceptible to operator error due to the manual measurement process. To solve this problem, a prototype handheld device was developed based on sensing fruit resistance to achieve automatic on-site firmness measurement of fruit with edible peel and provide commonly used firmness-related parameters. The prototype’s precision was verified by analyzing the repeatability and reproducibility of the measurement results with four Shore hardness blocks. The relative standard deviations (RSDs) of the results obtained by the same operator were less than 0.61%, and there was no significant difference among the results obtained by different operators (p < 0.05), which indicated that the prototype could provide reliable measurement results. A case study of peaches was performed, and the results showed that (1) the prototype had better performance than a commercial penetrometer, (2) two commonly used firmness-related parameters could be predicted based on regression models between a texture analyzer and the prototype readings (R2P = 0.908 and RMSEP = 4.191 N for maximum force; R2P = 0.923 and RMSEP = 1.613 N mm-1 for initial slope), (3) changes in the prototype readings for peaches during growth corresponded with the growth characteristics, and (4) the distribution and changes of peach firmness over time could be visualized based on 3D models of the prototype readings. Keywords: Automatic, Fruit firmness, Handheld device, High precision, Peach.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"74 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78650668","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}
HighlightsSolved the problem of optimal design, in the sense of minimal film usage, of round bale diameter and height.Necessary and sufficient optimality conditions derived in the form of easy-to-solve cubic equations.Bales of a maximum volume achievable with an actual wrapper and of optimal dimensions ensure minimal film usage.Up to 10% savings in film usage if bale dimensions are optimally designed and wrapping parameters properly selected.Abstract. The combined 3D method is used for wrapping cylindrical bales of agricultural materials based on biaxial rotation of the film applicators. The demand for minimization of plastic film consumption keeps increasing, with the goal to save the environment, reduce plastic costs, and minimize wrapping time. Consequently, methods have been reported to solve the problem of optimal wrapping parameters for the conventional wrapping method. In this article, a model-based problem of such a design based on round bale dimensions (diameter and height) that minimizes film consumption for the combined 3D method is mathematically formulated and analyzed. The film consumption per unit of bale volume is used as a measure of film usage. Generally, it is difficult to find the optimal bale dimensions that minimize the original film usage index, due to the discontinuity of the index. Thus, near-optimal parameters, being as important as optimal parameters for engineering applications, are looked for. The problem of selecting near-optimal bale dimensions was constructed by minimizing the continuous lower bound of the original film usage index. The necessary and sufficient optimality conditions for near-optimal bale dimensions were established in the form of standard cubic equations, which can easily be solved using both analytical and numerical methods. Based on the optimality conditions, analytical and numerical analyses were performed of the influence of film width, pre-assumed bale volume, and numbers of bottom and upper film layers on the near-optimal bale dimensions and film usage. The results indicated that the near-optimal bale diameter and height, hereinafter called optimal, monotonically increase, while the optimal film consumption monotonically decreases, with increasing pre-assumed bale volume. Therefore, it is recommended to use bales of a maximum volume achievable with an actual wrapper and of optimal dimensions, i.e., diameter and height. The film width also influences the optimal bale dimensions and film usage: the wider the film, the smaller the minimal film usage. To confirm the effect of near-optimal bale design on film usage, the errors of the near-optimality were examined for four to sixteen film layers. The results of the numerical experiments demonstrated that for four to sixteen layers of film, there are compositions of the bottom and upper film layers for which the relative near-optimality errors do not exceed 0.01% whenever the optimal bale dimensions are used. Simultaneously, inappropriate selection
{"title":"Optimization and Analysis of Plastic Film Consumption for Wrapping Round Baled Silage Using Combined 3D Method Considering Effects of Bale Dimensions","authors":"A. Stankiewicz","doi":"10.13031/TRANS.14137","DOIUrl":"https://doi.org/10.13031/TRANS.14137","url":null,"abstract":"HighlightsSolved the problem of optimal design, in the sense of minimal film usage, of round bale diameter and height.Necessary and sufficient optimality conditions derived in the form of easy-to-solve cubic equations.Bales of a maximum volume achievable with an actual wrapper and of optimal dimensions ensure minimal film usage.Up to 10% savings in film usage if bale dimensions are optimally designed and wrapping parameters properly selected.Abstract. The combined 3D method is used for wrapping cylindrical bales of agricultural materials based on biaxial rotation of the film applicators. The demand for minimization of plastic film consumption keeps increasing, with the goal to save the environment, reduce plastic costs, and minimize wrapping time. Consequently, methods have been reported to solve the problem of optimal wrapping parameters for the conventional wrapping method. In this article, a model-based problem of such a design based on round bale dimensions (diameter and height) that minimizes film consumption for the combined 3D method is mathematically formulated and analyzed. The film consumption per unit of bale volume is used as a measure of film usage. Generally, it is difficult to find the optimal bale dimensions that minimize the original film usage index, due to the discontinuity of the index. Thus, near-optimal parameters, being as important as optimal parameters for engineering applications, are looked for. The problem of selecting near-optimal bale dimensions was constructed by minimizing the continuous lower bound of the original film usage index. The necessary and sufficient optimality conditions for near-optimal bale dimensions were established in the form of standard cubic equations, which can easily be solved using both analytical and numerical methods. Based on the optimality conditions, analytical and numerical analyses were performed of the influence of film width, pre-assumed bale volume, and numbers of bottom and upper film layers on the near-optimal bale dimensions and film usage. The results indicated that the near-optimal bale diameter and height, hereinafter called optimal, monotonically increase, while the optimal film consumption monotonically decreases, with increasing pre-assumed bale volume. Therefore, it is recommended to use bales of a maximum volume achievable with an actual wrapper and of optimal dimensions, i.e., diameter and height. The film width also influences the optimal bale dimensions and film usage: the wider the film, the smaller the minimal film usage. To confirm the effect of near-optimal bale design on film usage, the errors of the near-optimality were examined for four to sixteen film layers. The results of the numerical experiments demonstrated that for four to sixteen layers of film, there are compositions of the bottom and upper film layers for which the relative near-optimality errors do not exceed 0.01% whenever the optimal bale dimensions are used. Simultaneously, inappropriate selection ","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"42 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84843938","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}
Xin Tian, Patrick M. Stump, A. Vacca, S. Fiorati, F. Pintore
HighlightsTwo methods (VPM and HVM) are proposed to improve the hydraulic system efficiency of agricultural tractors.VPM and HVM both target reducing the power loss at the flow control valve of the hydraulic system.The solutions are presented conceptually and then numerically modeled, and VPM is tested on an actual tractor.Results show that the VPM solution achieves 6.7% power saving, while HVM achieves 15.6% power saving.Abstract. Load sensing (LS) is a dominant fluid power actuation technology in mobile machines, particularly in construction and agriculture. It has the advantage of guaranteeing good controllability in systems with multiple actuators while promoting higher energy efficiency. Several variants of LS systems have been proposed over the years, and research on cost-effective methods to further increase their efficiency is still of interest for original equipment manufacturers (OEMs) and the fluid power community. This article presents two solution, referred to as variable pump margin (VPM) and hybrid variable margin (HVM), suitable to improve the energy efficiency in pre-compensated LS systems such as those used in agricultural tractors. Both methods allow either downsizing the control valves or reducing the power consumption over the working range. Compared to a standard LS system, the VPM solution lowers the pump pressure using an electronic proportional pressure-reducing valve (ep-PRV), while the HVM solution uses a second ep-PRV in the compensator’s pilot line to further minimize the pressure differential across the LS valve. Simulation and experimental results show that, among the main working conditions, the VPM solution on average achieved 6.7% power saving over the standard LS system, while the model predicted an average improvement of 15.6% for the HVM solution. Keywords: Efficiency, Experiments, Hydraulic, Load sensing, Modeling, Pump.
{"title":"Power-Saving Solutions for Pre-Compensated Load-Sensing Systems on Mobile Machines","authors":"Xin Tian, Patrick M. Stump, A. Vacca, S. Fiorati, F. Pintore","doi":"10.13031/trans.14376","DOIUrl":"https://doi.org/10.13031/trans.14376","url":null,"abstract":"HighlightsTwo methods (VPM and HVM) are proposed to improve the hydraulic system efficiency of agricultural tractors.VPM and HVM both target reducing the power loss at the flow control valve of the hydraulic system.The solutions are presented conceptually and then numerically modeled, and VPM is tested on an actual tractor.Results show that the VPM solution achieves 6.7% power saving, while HVM achieves 15.6% power saving.Abstract. Load sensing (LS) is a dominant fluid power actuation technology in mobile machines, particularly in construction and agriculture. It has the advantage of guaranteeing good controllability in systems with multiple actuators while promoting higher energy efficiency. Several variants of LS systems have been proposed over the years, and research on cost-effective methods to further increase their efficiency is still of interest for original equipment manufacturers (OEMs) and the fluid power community. This article presents two solution, referred to as variable pump margin (VPM) and hybrid variable margin (HVM), suitable to improve the energy efficiency in pre-compensated LS systems such as those used in agricultural tractors. Both methods allow either downsizing the control valves or reducing the power consumption over the working range. Compared to a standard LS system, the VPM solution lowers the pump pressure using an electronic proportional pressure-reducing valve (ep-PRV), while the HVM solution uses a second ep-PRV in the compensator’s pilot line to further minimize the pressure differential across the LS valve. Simulation and experimental results show that, among the main working conditions, the VPM solution on average achieved 6.7% power saving over the standard LS system, while the model predicted an average improvement of 15.6% for the HVM solution. Keywords: Efficiency, Experiments, Hydraulic, Load sensing, Modeling, Pump.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"19 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85823326","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}
Y. Kaizu, T. Shimada, Yusuke Takahashi, S. Igarashi, Hiroyuki Yamada, K. Furuhashi, K. Imou
HighlightsA small, automatically guided electric robot boat was developed to control the growth of aquatic plants in lakes.The robot boat was able to mow without becoming entangled with aquatic plants due to the paddle propulsion mechanism.The average speed was 0.41 m s-1, and the lateral deviation from the set path was 9.4 cm.The growth restraint effect was confirmed using aerial images collected by a drone.Abstract. At present, aquatic plants are becoming a problem in various lakes. Aquatic weeds that grow to high densities cause decreases in the oxygen concentration in the water, accumulation of sludge, and adverse effects on water use facilities and fisheries. Although there are large machines for cutting and harvesting aquatic plants, their use is limited due to their high cost, large size, and heavy weight. On the other hand, manual cutting is very labor intensive and inefficient. Therefore, in this research, we developed a labor-saving and low-cost robot boat to mow aquatic plants. This robot boat is automatically controlled by a real-time kinematic global navigational satellite system (RTK-GNSS) and is characterized by its small size, light weight, excellent portability, and low energy consumption. In addition, a paddle mechanism that replaces a conventional propeller was introduced as a propulsion mechanism to prevent entanglement of water plants and enable long-term automatic navigation. Mowing lotus (Nelumbo nucifera) in Lake Izunuma, Miyagi prefecture, Japan, confirmed that mowing could be properly conducted with a lateral deviation of 9.4 cm, average speed of 0.41 m s-1, and average power consumption of 518 W even when lotus was at its densest growth. If the cutting width of the robot boat was 1.2 m and the sidelap width was 0.3 m, the theoretical field work rate would be 0.133 ha h-1. Images captured by a drone confirmed that cutting with the robot boat was effective in suppressing the growth of lotus. It was found that the effect of suppressing growth was maximized by mowing at the time when the stopping leaves appeared in the late growth stage of lotus. Keywords: Autonomous navigation, Lotus, Moving baseline, Robot operation system, RTK-GNSS, Virtual private network.
一种小型、自动引导的电动机器人船被开发出来，用于控制湖泊中水生植物的生长。由于采用桨推进装置，这艘机器船能够在不与水生植物纠缠的情况下进行割草。平均速度为0.41 m s-1，与设定路径的横向偏差为9.4 cm。利用无人机采集的航拍图像验证了生长抑制效果。目前，水生植物正在成为各种湖泊的一个问题。水草的高密度生长导致水中氧浓度降低，污泥堆积，对用水设施和渔业产生不利影响。虽然有大型机器用于切割和收获水生植物，但由于成本高、体积大、重量重，它们的使用受到限制。另一方面，手工切割是非常劳动密集和效率低下的。因此，在本研究中，我们开发了一种省力、低成本的水生植物割草机器人船。该机器人船由实时动态全球导航卫星系统(RTK-GNSS)自动控制，具有体积小、重量轻、便携性好、能耗低的特点。此外，还引入了一种取代传统螺旋桨的桨形机构作为推进机构，以防止水草缠绕，并实现长期自动导航。在日本宫城县出沼湖对荷花(Nelumbo nucifera)进行刈割，证实荷花生长最密集时，其横向偏差为9.4 cm，平均速度为0.41 m s-1，平均功耗为518 W。如果机器人船的切割宽度为1.2 m，侧舷宽度为0.3 m，则理论现场工作速率为0.133 ha h-1。无人机拍摄的图像证实，用机器船切割可以有效抑制荷花的生长。结果表明，在荷花生长后期出现停叶时，割草抑制生长的效果最大。关键词:自主导航，Lotus，移动基线，机器人操作系统，RTK-GNSS，虚拟专网
{"title":"Development of a Small Electric Robot Boat for Mowing Aquatic Weeds","authors":"Y. Kaizu, T. Shimada, Yusuke Takahashi, S. Igarashi, Hiroyuki Yamada, K. Furuhashi, K. Imou","doi":"10.13031/trans.14295","DOIUrl":"https://doi.org/10.13031/trans.14295","url":null,"abstract":"HighlightsA small, automatically guided electric robot boat was developed to control the growth of aquatic plants in lakes.The robot boat was able to mow without becoming entangled with aquatic plants due to the paddle propulsion mechanism.The average speed was 0.41 m s-1, and the lateral deviation from the set path was 9.4 cm.The growth restraint effect was confirmed using aerial images collected by a drone.Abstract. At present, aquatic plants are becoming a problem in various lakes. Aquatic weeds that grow to high densities cause decreases in the oxygen concentration in the water, accumulation of sludge, and adverse effects on water use facilities and fisheries. Although there are large machines for cutting and harvesting aquatic plants, their use is limited due to their high cost, large size, and heavy weight. On the other hand, manual cutting is very labor intensive and inefficient. Therefore, in this research, we developed a labor-saving and low-cost robot boat to mow aquatic plants. This robot boat is automatically controlled by a real-time kinematic global navigational satellite system (RTK-GNSS) and is characterized by its small size, light weight, excellent portability, and low energy consumption. In addition, a paddle mechanism that replaces a conventional propeller was introduced as a propulsion mechanism to prevent entanglement of water plants and enable long-term automatic navigation. Mowing lotus (Nelumbo nucifera) in Lake Izunuma, Miyagi prefecture, Japan, confirmed that mowing could be properly conducted with a lateral deviation of 9.4 cm, average speed of 0.41 m s-1, and average power consumption of 518 W even when lotus was at its densest growth. If the cutting width of the robot boat was 1.2 m and the sidelap width was 0.3 m, the theoretical field work rate would be 0.133 ha h-1. Images captured by a drone confirmed that cutting with the robot boat was effective in suppressing the growth of lotus. It was found that the effect of suppressing growth was maximized by mowing at the time when the stopping leaves appeared in the late growth stage of lotus. Keywords: Autonomous navigation, Lotus, Moving baseline, Robot operation system, RTK-GNSS, Virtual private network.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79661600","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}
HighlightsRetention and spread of droplets with seven adjuvants were investigated on flat leaves.Surface tension of spray solutions, leaf wettability, and roughness strongly affected droplet retention and spread.Complete droplet retention occurred on hydrophilic leaves with all adjuvants and concentrations.High retention and spread on superhydrophobic leaves were achieved with the organo-silicone adjuvant.No retention occurred on superhydrophobic leaf surfaces with the hydrocolloid polymer adjuvant.Abstract. To optimize spray application efficiency, it is necessary to understand how the addition of adjuvants modifies the deposition properties of spray droplets on leaf surfaces due to variations in adhesive characteristics, such as roughness and wettability. Retention and spread of droplets with seven commercially available adjuvants were tested and compared at different concentrations. Tests were conducted with three leaf surfaces ranging in roughness and wettability from very smooth and hydrophilic to very rough and superhydrophobic. The adjuvants were formulated with non-ionic surfactant, crop oil, seed oil, organo-silicone, hydrocolloid polymer, or combinations of these agents as primary ingredients. Droplets of approximately 340 µm diameter were emitted from a streamed mono-sized generator. Droplet impact and spread were recorded with a 3D imaging system consisting of three high-speed digital cameras and analyzed using 3D motion analysis software. Retention and spread were determined by comparing droplet liquid volumes and droplet cross-sectional areas before and after impact, respectively. The surface tension of spray solutions and wettability of leaf surfaces strongly affected droplet retention. Droplets with lower surface tension were more likely to achieve high retention than those with higher surface tension. Droplet retention generally decreased with increasing leaf roughness-wettability. All droplets with and without adjuvants achieved 100% retention on the hydrophilic leaf surface. Addition of non-ionic, oil, or organo-silicone based adjuvants in the spray solution improved droplet retention on hydrophobic leaves, while the organo-silicone based adjuvant achieved the highest retention on superhydrophobic leaf surfaces. Droplet retention with the hydrocolloid polymer adjuvant was generally comparable to the other six adjuvants on the hydrophilic leaves and on the hydrophobic leaves with intermediate roughness and wettability but failed to achieve any retention on the superhydrophobic leaves. To improve droplet retention and adhesion, selection of adjuvants representing the non-ionic, oil, organo-silicone, blended, or hydrocolloid-based additives for enhancing spray solution performance must comply with the leaf surface characteristics. Keywords: Droplet rebound, High-speed imaging, Leaf wettability, Pesticide droplet deposition, Topography parameters.
{"title":"Retention and Spread Capability of Impacted Droplets with Surfactant and Hydrocolloid Based Adjuvants","authors":"J. Abbott, Heping Zhu, H. Jeon","doi":"10.13031/trans.14461","DOIUrl":"https://doi.org/10.13031/trans.14461","url":null,"abstract":"HighlightsRetention and spread of droplets with seven adjuvants were investigated on flat leaves.Surface tension of spray solutions, leaf wettability, and roughness strongly affected droplet retention and spread.Complete droplet retention occurred on hydrophilic leaves with all adjuvants and concentrations.High retention and spread on superhydrophobic leaves were achieved with the organo-silicone adjuvant.No retention occurred on superhydrophobic leaf surfaces with the hydrocolloid polymer adjuvant.Abstract. To optimize spray application efficiency, it is necessary to understand how the addition of adjuvants modifies the deposition properties of spray droplets on leaf surfaces due to variations in adhesive characteristics, such as roughness and wettability. Retention and spread of droplets with seven commercially available adjuvants were tested and compared at different concentrations. Tests were conducted with three leaf surfaces ranging in roughness and wettability from very smooth and hydrophilic to very rough and superhydrophobic. The adjuvants were formulated with non-ionic surfactant, crop oil, seed oil, organo-silicone, hydrocolloid polymer, or combinations of these agents as primary ingredients. Droplets of approximately 340 µm diameter were emitted from a streamed mono-sized generator. Droplet impact and spread were recorded with a 3D imaging system consisting of three high-speed digital cameras and analyzed using 3D motion analysis software. Retention and spread were determined by comparing droplet liquid volumes and droplet cross-sectional areas before and after impact, respectively. The surface tension of spray solutions and wettability of leaf surfaces strongly affected droplet retention. Droplets with lower surface tension were more likely to achieve high retention than those with higher surface tension. Droplet retention generally decreased with increasing leaf roughness-wettability. All droplets with and without adjuvants achieved 100% retention on the hydrophilic leaf surface. Addition of non-ionic, oil, or organo-silicone based adjuvants in the spray solution improved droplet retention on hydrophobic leaves, while the organo-silicone based adjuvant achieved the highest retention on superhydrophobic leaf surfaces. Droplet retention with the hydrocolloid polymer adjuvant was generally comparable to the other six adjuvants on the hydrophilic leaves and on the hydrophobic leaves with intermediate roughness and wettability but failed to achieve any retention on the superhydrophobic leaves. To improve droplet retention and adhesion, selection of adjuvants representing the non-ionic, oil, organo-silicone, blended, or hydrocolloid-based additives for enhancing spray solution performance must comply with the leaf surface characteristics. Keywords: Droplet rebound, High-speed imaging, Leaf wettability, Pesticide droplet deposition, Topography parameters.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"21 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77115298","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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