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}
HighlightsFilter strip processes for water pollutant reductions were quantified from 74 studies with almost 300 data points.Regression was significant versus width (sediment, N, P), area ratio (sediment, atrazine), and Ks (N, P, atrazine, alachlor).This review discusses ten functional factors affecting FS efficiency as well as FS monitoring recommendations.Cost-effectiveness was assessed and varies considerably by influent load and treatment effectiveness.Abstract. Filter strips (FSs) are edge-of-field conservation practices commonly implemented to reduce flux of sediment, nutrients, and other constituents from agricultural fields. While various aspects of FS effectiveness have been reviewed, this study provides a comprehensive summary of FS efficiency data for sediment, nutrients, pesticides, and pathogens as part of a special collection focused on agricultural conservation practices. This analysis also fills an important gap by assessing performance-based FS costs and cost-effectiveness. Data from 74 U.S. and international studies with 294 different treatments and 3,050 replications were compiled and analyzed. Results showed that runoff reduction tended to increase with increasing FS width up to about 15 m and that sediment reduction was significantly related to the ratio of FS area to drainage area and to FS width, with reduction tending to increase with increasing width up to about 20 m. Total P reduction was significantly related to FS soil saturated hydraulic conductivity, and total N reduction was significantly related to both saturated hydraulic conductivity and width. Total P and total N reductions both tended to increase with increasing FS width up to about 20 m and with increasing FS slope up to about 10%. Annualized FS costs were estimated to range from $314 to $865 ha-1 year-1 for different FS implementations. A major component of the cost is the opportunity cost of taking land out of production. Costs per unit of sediment retained by FS systems ranged from $10.3 to $18.6 Mg-1. A comprehensive assessment of FS cost-effectiveness (cost:benefit) is needed. Monitoring equipment, approaches, and recommendations are discussed, acknowledging the challenges of implementing field-scale FS studies. This information is critical to guide on-farm and programmatic FS decisions and to increase the scientific understanding of this commonly used agricultural conservation practice. Keywords: Best management practice, Buffer strip, Nonpoint-source pollution, Riparian buffer, Vegetated filter strip.
{"title":"Review of Filter Strip Performance and Function for Improving Water Quality from Agricultural Lands","authors":"K. Douglas-Mankin, M. Helmers, R. Harmel","doi":"10.13031/TRANS.14169","DOIUrl":"https://doi.org/10.13031/TRANS.14169","url":null,"abstract":"HighlightsFilter strip processes for water pollutant reductions were quantified from 74 studies with almost 300 data points.Regression was significant versus width (sediment, N, P), area ratio (sediment, atrazine), and Ks (N, P, atrazine, alachlor).This review discusses ten functional factors affecting FS efficiency as well as FS monitoring recommendations.Cost-effectiveness was assessed and varies considerably by influent load and treatment effectiveness.Abstract. Filter strips (FSs) are edge-of-field conservation practices commonly implemented to reduce flux of sediment, nutrients, and other constituents from agricultural fields. While various aspects of FS effectiveness have been reviewed, this study provides a comprehensive summary of FS efficiency data for sediment, nutrients, pesticides, and pathogens as part of a special collection focused on agricultural conservation practices. This analysis also fills an important gap by assessing performance-based FS costs and cost-effectiveness. Data from 74 U.S. and international studies with 294 different treatments and 3,050 replications were compiled and analyzed. Results showed that runoff reduction tended to increase with increasing FS width up to about 15 m and that sediment reduction was significantly related to the ratio of FS area to drainage area and to FS width, with reduction tending to increase with increasing width up to about 20 m. Total P reduction was significantly related to FS soil saturated hydraulic conductivity, and total N reduction was significantly related to both saturated hydraulic conductivity and width. Total P and total N reductions both tended to increase with increasing FS width up to about 20 m and with increasing FS slope up to about 10%. Annualized FS costs were estimated to range from $314 to $865 ha-1 year-1 for different FS implementations. A major component of the cost is the opportunity cost of taking land out of production. Costs per unit of sediment retained by FS systems ranged from $10.3 to $18.6 Mg-1. A comprehensive assessment of FS cost-effectiveness (cost:benefit) is needed. Monitoring equipment, approaches, and recommendations are discussed, acknowledging the challenges of implementing field-scale FS studies. This information is critical to guide on-farm and programmatic FS decisions and to increase the scientific understanding of this commonly used agricultural conservation practice. Keywords: Best management practice, Buffer strip, Nonpoint-source pollution, Riparian buffer, Vegetated filter strip.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"3 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88594468","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}
Chengda Sun, Weimin Ding, Changding Liu, Weifeng Yao, Lilian Shi
HighlightsA measurement device for droplet mass deposit was improved to enhance its performance.A wireless data transmission system was used to achieve convenient data sharing.A user interface was designed for display and analysis of the measurement results.A positioning mechanism was designed for arranging measurement devices promptly.Abstract. Measurement of droplet mass deposit is important in spray research and spray performance evaluation. In this article, an online measurement device for droplet mass deposit was improved based on the original design. The measurement resolution, precision, and data stability were improved by optimization of the structure and components and by data filtering. The resolution reached 0.00067 mg cm-2. Comparison tests showed that the relative error between the original device and an analytical balance was 6.68% to 8.48%, and the relative error between the improved device and the analytical balance was 5.24% to 6.15%. Compared with the original device, the relative error decreased and the precision improved. The relative error between the improved device and a tracer method was 5.11% to 6.99%, and the precision of the improved device was close to that of the tracer method. A positioning mechanism was designed to arrange measurement devices promptly in the test area, and a wireless data transmission system was used to achieve convenient data sharing. A user interface was designed to display the results in the form of tables and contour maps. Tests were conducted to measure the droplet mass deposit distribution of one nozzle, the droplet mass deposit distribution in a tree canopy, and the uniformity of the droplet mass deposit distribution in a small horizontal area. The results showed that the improved measurement device could provide data promptly and conveniently for spray research and spray performance evaluation. Keywords: Device improvement, Mass distribution, Wireless communication.
{"title":"Improvement and Experiment for Online Measurement of Droplet Mass Deposit","authors":"Chengda Sun, Weimin Ding, Changding Liu, Weifeng Yao, Lilian Shi","doi":"10.13031/trans.14219","DOIUrl":"https://doi.org/10.13031/trans.14219","url":null,"abstract":"HighlightsA measurement device for droplet mass deposit was improved to enhance its performance.A wireless data transmission system was used to achieve convenient data sharing.A user interface was designed for display and analysis of the measurement results.A positioning mechanism was designed for arranging measurement devices promptly.Abstract. Measurement of droplet mass deposit is important in spray research and spray performance evaluation. In this article, an online measurement device for droplet mass deposit was improved based on the original design. The measurement resolution, precision, and data stability were improved by optimization of the structure and components and by data filtering. The resolution reached 0.00067 mg cm-2. Comparison tests showed that the relative error between the original device and an analytical balance was 6.68% to 8.48%, and the relative error between the improved device and the analytical balance was 5.24% to 6.15%. Compared with the original device, the relative error decreased and the precision improved. The relative error between the improved device and a tracer method was 5.11% to 6.99%, and the precision of the improved device was close to that of the tracer method. A positioning mechanism was designed to arrange measurement devices promptly in the test area, and a wireless data transmission system was used to achieve convenient data sharing. A user interface was designed to display the results in the form of tables and contour maps. Tests were conducted to measure the droplet mass deposit distribution of one nozzle, the droplet mass deposit distribution in a tree canopy, and the uniformity of the droplet mass deposit distribution in a small horizontal area. The results showed that the improved measurement device could provide data promptly and conveniently for spray research and spray performance evaluation. Keywords: Device improvement, Mass distribution, Wireless communication.","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":"88055536","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}
HighlightsPermittivity measurements were taken for traditional and high-oleic runner-type peanut pods and kernels at microwave frequencies.The dielectric constant, loss factor, loss tangent, and complex plane were compared between the two cultivars to observe any effect caused by the high-oleic trait.Despite differences in composition, minimal to no differences were observed in permittivity between the two cultivars.Abstract. Different cultivars of peanuts containing higher amounts of oleic acid have been developed to improve oxidative stability and overall peanut quality. Increasing oleic acid levels and decreasing linoleic acid levels in peanuts deter lipid oxidation, preventing the creation of off-flavors and increasing the shelf life. Since their conception, high-oleic peanuts have been tested from chemical and sensory perspectives to observe differences between them and traditional peanuts. Such tests have shown minimal differences, if any. However, tests to observe the effect of changing the levels of oleic and linoleic acid on permittivity, which is often used for nondestructive determination of the moisture content and bulk density of foods and agricultural products, have not been reported. Thus, a vector network analyzer (VNA) was used to take free-space transmission measurements of the complex permittivities of high-oleic and traditional runner-type peanut pods and kernels. Measurements were taken at 23°C between 5 and 9 GHz. Measurements yielded the dielectric constant and loss factor, which are often correlated to moisture content. Analysis was performed to compare the changes in the dielectric constant, loss factor, and loss tangent with moisture content for high-oleic and traditional peanuts. Linear trends were observed for each parameter with increasing moisture content for both cultivars. Results from the complex plane showed coefficient of determination (r2) values greater than 0.9 for pods and kernels. Therefore, at microwave frequencies, changing the levels of oleic and linoleic acid within the peanuts was observed to have minimal to no effect on their permittivity. Thus, moisture calibrations based on correlations between dielectric properties and moisture content for traditional runner-type peanuts can be applied to high-oleic cultivars. Keywords: Dielectric properties, Free-space transmission measurements, Microwave measurements, Oleic acid, Peanut kernels, Peanut pods.
{"title":"Comparison of Dielectric Properties of Traditional and High-Oleic Runner-Type Peanuts at Microwave Frequencies","authors":"M. Lewis, S. Trabelsi","doi":"10.13031/trans.14323","DOIUrl":"https://doi.org/10.13031/trans.14323","url":null,"abstract":"HighlightsPermittivity measurements were taken for traditional and high-oleic runner-type peanut pods and kernels at microwave frequencies.The dielectric constant, loss factor, loss tangent, and complex plane were compared between the two cultivars to observe any effect caused by the high-oleic trait.Despite differences in composition, minimal to no differences were observed in permittivity between the two cultivars.Abstract. Different cultivars of peanuts containing higher amounts of oleic acid have been developed to improve oxidative stability and overall peanut quality. Increasing oleic acid levels and decreasing linoleic acid levels in peanuts deter lipid oxidation, preventing the creation of off-flavors and increasing the shelf life. Since their conception, high-oleic peanuts have been tested from chemical and sensory perspectives to observe differences between them and traditional peanuts. Such tests have shown minimal differences, if any. However, tests to observe the effect of changing the levels of oleic and linoleic acid on permittivity, which is often used for nondestructive determination of the moisture content and bulk density of foods and agricultural products, have not been reported. Thus, a vector network analyzer (VNA) was used to take free-space transmission measurements of the complex permittivities of high-oleic and traditional runner-type peanut pods and kernels. Measurements were taken at 23°C between 5 and 9 GHz. Measurements yielded the dielectric constant and loss factor, which are often correlated to moisture content. Analysis was performed to compare the changes in the dielectric constant, loss factor, and loss tangent with moisture content for high-oleic and traditional peanuts. Linear trends were observed for each parameter with increasing moisture content for both cultivars. Results from the complex plane showed coefficient of determination (r2) values greater than 0.9 for pods and kernels. Therefore, at microwave frequencies, changing the levels of oleic and linoleic acid within the peanuts was observed to have minimal to no effect on their permittivity. Thus, moisture calibrations based on correlations between dielectric properties and moisture content for traditional runner-type peanuts can be applied to high-oleic cultivars. Keywords: Dielectric properties, Free-space transmission measurements, Microwave measurements, Oleic acid, Peanut kernels, Peanut pods.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"482 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86763616","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}
Dujin Wang, Yizhong Wang, Ming Li, Xinting Yang, Jianwei Wu, Wenyong Li
Highlights The proposed method detected thrips and whitefly more accurately than previous methods. The proposed method demonstrated good robustness to illumination reflections and different pest densities. Small pest detection is improved by adding large-scale feature maps and more residual units to a shallow network. Machine vision and deep learning create an end-to-end model to detect smallsmall pests on sticky traps in field conditions. Abstract. Pest detection is the basis of precise control in vegetable greenhouses. To improve the detection accuracy and robustness of two common small pests in greenhouses, whitefly and thrips, this study proposes a novel small object detection approach based on the YOLOv4 model. Yellow sticky trap (YST) images at the original resolution (2560x1920 pixels) were collected using a pest monitoring equipment in a greenhouse. They were then cropped and labeled to create the sub-images (416x416 pixels) to construct an experimental dataset. The labeled images of this study (900 training, 100 validation, and 200 test) are available for comparative studies. To enhance the model‘s ability to detect small pests, the feature map at the 8-fold downsampling layer in the backbone network was merged with the feature map at the 4-fold downsampling layer to generate a new layer and output a feature map with a size of 104x104 pixels. Furthermore, the residual units in the first two residual blocks are enlarged by four times to extract more shallow image features and the location information of target pests to withstand image degradation in the field. The experimental results show that the detection mAP of whitefly and thrips using the proposed approach is improved by 8.2% and 3.4% compared with the YOLOv3 and YOLOv4 models, respectively. The detection performance slightly decreases as the pest densities increase in the YST image, but the mAP value was still 92.7% in the high-density dataset, which indicates that the proposed model has good robustness over a range of pest densities. Compared with some previous similar studies, the proposed method has better potential to monitor whitefly and thrips using YSTs in field conditions.
{"title":"Using an Improved YOLOv4 Deep Learning Network for Accurate Detection of Whitefly and Thrips on Sticky Trap Images","authors":"Dujin Wang, Yizhong Wang, Ming Li, Xinting Yang, Jianwei Wu, Wenyong Li","doi":"10.13031/TRANS.14394","DOIUrl":"https://doi.org/10.13031/TRANS.14394","url":null,"abstract":"Highlights The proposed method detected thrips and whitefly more accurately than previous methods. The proposed method demonstrated good robustness to illumination reflections and different pest densities. Small pest detection is improved by adding large-scale feature maps and more residual units to a shallow network. Machine vision and deep learning create an end-to-end model to detect smallsmall pests on sticky traps in field conditions. Abstract. Pest detection is the basis of precise control in vegetable greenhouses. To improve the detection accuracy and robustness of two common small pests in greenhouses, whitefly and thrips, this study proposes a novel small object detection approach based on the YOLOv4 model. Yellow sticky trap (YST) images at the original resolution (2560x1920 pixels) were collected using a pest monitoring equipment in a greenhouse. They were then cropped and labeled to create the sub-images (416x416 pixels) to construct an experimental dataset. The labeled images of this study (900 training, 100 validation, and 200 test) are available for comparative studies. To enhance the model‘s ability to detect small pests, the feature map at the 8-fold downsampling layer in the backbone network was merged with the feature map at the 4-fold downsampling layer to generate a new layer and output a feature map with a size of 104x104 pixels. Furthermore, the residual units in the first two residual blocks are enlarged by four times to extract more shallow image features and the location information of target pests to withstand image degradation in the field. The experimental results show that the detection mAP of whitefly and thrips using the proposed approach is improved by 8.2% and 3.4% compared with the YOLOv3 and YOLOv4 models, respectively. The detection performance slightly decreases as the pest densities increase in the YST image, but the mAP value was still 92.7% in the high-density dataset, which indicates that the proposed model has good robustness over a range of pest densities. Compared with some previous similar studies, the proposed method has better potential to monitor whitefly and thrips using YSTs in field conditions.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"7 1","pages":"0"},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91309553","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}
HighlightsWe developed and evaluated a variable-rate irrigation (VRI) management method for five crop years in the Mississippi Delta.VRI management significantly reduced irrigation water use in comparison with uniform-rate irrigation (URI). There was no significant difference in grain yield and irrigation water productivity between VRI and URI management.Soil apparent electrical conductivity (ECa) was used to delineate irrigation management zones and generate VRI prescriptions.Sensor-measured soil water content was used in irrigation scheduling.Abstract. Variable-rate irrigation (VRI) allows producers to site-specifically apply irrigation water at variable rates within a field to account for the temporal and spatial variability in soil and plant characteristics. Developing practical VRI methods and documenting the benefits of VRI application are critical to accelerate the adoption of VRI technologies. Using apparent soil electrical conductivity (ECa) and soil moisture sensors, a VRI method was developed and evaluated with corn and soybean for five crop years in the Mississippi Delta. Soil ECa of the study fields was mapped and used to delineate VRI management zones and create VRI prescriptions. Irrigation was scheduled using soil volumetric water content measured by soil moisture sensors. A center pivot VRI system was employed to deliver irrigation water according to the VRI prescription. Grain yield, irrigation water use, and irrigation water productivity in the VRI treatment were determined and compared with that in a uniform-rate irrigation (URI) treatment. Results showed that the grain yield and irrigation water productivity between the VRI and URI treatments were not statistically different with both corn and soybean crops. The VRI management significantly reduced the amount of irrigation water by 22% in corn and by 11% in soybean (p = 0.05). Adoption of VRI management could improve irrigation water use efficiency in the Mississippi Delta. Keywords: Soil electrical conductivity, Soil moisture sensor, Variable rate irrigation, Water management.
{"title":"Development and Evaluation of a Variable-Rate Irrigation Management Method in the Mississippi Delta","authors":"R. Sui, J. Baggard","doi":"10.13031/TRANS.14019","DOIUrl":"https://doi.org/10.13031/TRANS.14019","url":null,"abstract":"HighlightsWe developed and evaluated a variable-rate irrigation (VRI) management method for five crop years in the Mississippi Delta.VRI management significantly reduced irrigation water use in comparison with uniform-rate irrigation (URI). There was no significant difference in grain yield and irrigation water productivity between VRI and URI management.Soil apparent electrical conductivity (ECa) was used to delineate irrigation management zones and generate VRI prescriptions.Sensor-measured soil water content was used in irrigation scheduling.Abstract. Variable-rate irrigation (VRI) allows producers to site-specifically apply irrigation water at variable rates within a field to account for the temporal and spatial variability in soil and plant characteristics. Developing practical VRI methods and documenting the benefits of VRI application are critical to accelerate the adoption of VRI technologies. Using apparent soil electrical conductivity (ECa) and soil moisture sensors, a VRI method was developed and evaluated with corn and soybean for five crop years in the Mississippi Delta. Soil ECa of the study fields was mapped and used to delineate VRI management zones and create VRI prescriptions. Irrigation was scheduled using soil volumetric water content measured by soil moisture sensors. A center pivot VRI system was employed to deliver irrigation water according to the VRI prescription. Grain yield, irrigation water use, and irrigation water productivity in the VRI treatment were determined and compared with that in a uniform-rate irrigation (URI) treatment. Results showed that the grain yield and irrigation water productivity between the VRI and URI treatments were not statistically different with both corn and soybean crops. The VRI management significantly reduced the amount of irrigation water by 22% in corn and by 11% in soybean (p = 0.05). Adoption of VRI management could improve irrigation water use efficiency in the Mississippi Delta. Keywords: Soil electrical conductivity, Soil moisture sensor, Variable rate irrigation, Water management.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"6 1","pages":"287-298"},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73231415","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}
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}
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