Transactions of the ASABE最新文献

{"title":"The Manitoba Land Calculator: A Tool to Estimate Land Requirements for Manure Application in Manitoba, Canada","authors":"R. Cordeiro, P. Loro, Marcos R. C. Cordeiro, C. Sawka, K. Ominski, D. Flaten","doi":"10.13031/TRANS.14613","DOIUrl":"https://doi.org/10.13031/TRANS.14613","url":null,"abstract":"HighlightsThe Manitoba Land Calculator is a tool to estimate land requirements for new and expanding livestock operations.This new tool reflects Manitoba production practices and recent advances in animal and crop performance.Considerably more land is needed for management of manure phosphorus than when only nitrogen is considered.Sufficient land for application of manure supports the environmental sustainability of livestock production.Abstract. The planning of new livestock and poultry facilities or expansion of existing facilities should ensure sufficient land for manure application. Decision support tools used to establish land requirements for manure nutrients should take into consideration advances in animal genetics, performance, feeding strategies, and available feeds. This article presents a new tool for estimating land requirements for new and expanding pig, beef, dairy, and poultry operations in the province of Manitoba, Canada. The Manitoba Land Calculator (MLC) estimates land requirements for manure nitrogen (N) and phosphorus (P). It uses a mass balance approach to estimate nutrient excretion by livestock and poultry based on typical Manitoba feeding practices, weight gain, and production cycles. Crop nutrient utilization and removals can be calculated for 20 common crops grown in Manitoba using reliable long-term yields and farm-specific crop areas. Two case studies (pig and poultry) were selected from the Livestock Technical Review Public Registry on the Government of Manitoba website to illustrate the inputs and outputs associated with the MLC. The results indicated that land requirements increased by 4.6-fold and 5.7-fold for the poultry and pig operations, respectively, compared to the previous provincial methodology due to the inclusion of P in the model. Securing additional land during the planning stages will support the implementation of nutrient stewardship principles that ensure the long-term environmental sustainability of livestock operations. Keywords: Animal production, Land requirements, Livestock and poultry, Manure, Mass balance, Nutrient excretion.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"146 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76085642","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}

{"title":"Nitrous Oxide and Methane Emissions from Beef Cattle Feedyard Pens Following Large Rainfall Events","authors":"D. Parker, K. Casey, Will Willis, B. Meyer","doi":"10.13031/trans.14480","DOIUrl":"https://doi.org/10.13031/trans.14480","url":null,"abstract":"HighlightsNitrous oxide and methane emissions were measured from a commercial beef feedyard following large rainfall events.Nitrous oxide emissions dropped below detection levels for ten days following a 77 mm rainfall event.Daily N2O and CH4 emissions followed a diel pattern, peaking at manure temperatures of 36°C to 38°C.Results will be used to refine empirical models for predicting GHG emissions from open-lot feedyards.Abstract. More than six million beef cattle are fed annually in feedyards on the semiarid Southern Great Plains (SGP). Manure deposited on the open-lot pen surfaces contributes to greenhouse gas (GHG) emissions. Nitrous oxide (N2O) and methane (CH4) are GHGs linked to climate change, and both have global warming potentials greater than carbon dioxide (CO2). Two sampling campaigns were conducted in 2019 to quantify N2O and CH4 emissions from open-lot pen surfaces. The occurrence of large, unforecast rainfall events during both campaigns provided an opportunity to compare GHG emissions from the dry manure before rainfall and from the wetted pen surface for one to two weeks following precipitation. Temporal variability was quantified by continuous sampling using six to eight automated flux chambers, a multiplexer system, and real-time analyzers. Spatial variability was quantified using a recirculating portable chamber on a 5 × 8 grid. Nitrous oxide emissions dropped below detection levels for ten days after the precipitation event. Nitrous oxide emissions were related to nitrification or other aerobic processes. Methane emissions dropped below detection levels for five days after the precipitation event and then increased to pre-rainfall levels by day 8. When present, N2O and CH4 emissions followed a diel pattern, with the highest emissions occurring during the afternoon when manure pack temperatures at the 25 mm depth were 36°C to 38°C and ambient temperatures were 31°C to 32°C. Average CH4 emissions from the feedyard pen surface were 96-fold lower than estimated enteric CH4 emissions. The results of this field research will be used to refine empirical models for predicting annual N2O and CH4 emissions from open-lot beef cattle feedyards on the semiarid SGP. Keywords: Beef cattle, Flux chamber, Greenhouse gas, Manure, Nitrous oxide, Rainfall.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"27 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90368727","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}

{"title":"Effects of Potassium Application and Straw Returning on Potassium Management and Benefit of Banana","authors":"Chao Zheng, Yang Xiaofei, Ke-xing Liu, Yongxiang Huang","doi":"10.13031/TRANS.14653","DOIUrl":"https://doi.org/10.13031/TRANS.14653","url":null,"abstract":"HighlightsThe effects of potash fertilizer and straw returning on a banana orchard were studied by field experiment.Fertilizer with straw was more conductive to potassium nutrient balance and improved banana yield and quality.The economic benefits of straw replacing different amounts of potassium fertilizer were compared.Abstract. To explore the effects of potash fertilizer and straw returning in banana production, a field experiment was carried out, and four treatments were set up: NP fertilizer (NP), NP fertilizer and banana straw (NP+St), NPK fertilizer (NPK), and NPK fertilizer and banana straw (NPK+St). Through the soil potassium balance, the effects of potash fertilizer and straw returning on the yield, quality, and economic benefits of bananas were studied. The results showed that the application of potash fertilizer and straw could improve banana yields. Compared with the NP treatment, the banana yields of the NP+St, NPK, and NPK+St treatments increased by 17.5%, 50.5%, and 71.6%, respectively. The order of banana yield, potassium balance coefficient, and nutrient accumulation was NPK+St > NP+St > NPK > NP. The NPK+St treatment also improved the recovery rate and agronomic utilization rate of potash fertilizer, which were higher than that of potassium application without straw (NPK) and straw application without potassium (NP+St). Potassium application with straw improved the banana yield, increased the total accumulation of nitrogen, phosphorus, and potassium, and improved the efficiency of potash fertilizer uptake by the crop. Therefore, this study demonstrates the importance of straw for maintaining the soil potassium balance in banana production. The input cost of potassium fertilizer was reduced, and the resource utilization of banana straw was realized by straw returning, which can be promoted in local agricultural production. Keywords: Banana, Potassium application, Potassium balance, Straw returning, Yield.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"7 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90492913","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}

{"title":"Development of a Guiding-Groove Precision Metering Device for High-Speed Planting of Soybean","authors":"Hao Shen, Zhang Junjie, X. Chen, Jian-Xin Dong, Yuxiang Huang, Jiangtao Shi","doi":"10.13031/TRANS.14307","DOIUrl":"https://doi.org/10.13031/TRANS.14307","url":null,"abstract":"Highlights To improve the performance for precision planting of soybean at high speeds, a guiding groove precision metering device was developed. The seed feeding and clearing processes were analyzed to determine the critical design and operational factors. The effects of critical metering parameters on the meter performance were simulated using the DEM. The metering performance was evaluated using bench tests. ABSTRACT Precision planting is the inevitable trend of agricultural development, and the promotion of precision planting technology is the key to increase crop yield. To improve the performance of precision planting at high speeds, a mechanical-type precision metering device was developed for soybean. The innovative feature of the device was the guiding-groove (GG) that provided “waiting areas” for seeds to form a line and subsequently enter the seed cells in an orderly and rapid fashion. By the force analysis, mechanical model of seed feeding stage was set up. Relationships between design parameters of the meter and the metering performance (multiple index, miss index, quality index and feeding efficiency index) were obtained through simulations using a discrete element model (DEM). The simulations conducted in this study were based on the central composite design (CCD). Then, the relationships were used to determine the design parameters to achieve the best metering performance. With these design parameters, the GG meter was fabricated and evaluated through bench tests. Results showed that the critical design parameters were the width of inner groove-wheel (L), cone angle of the shell (δ), the width of guiding-groove (L1), and the angle of the groove bottom surface to the horizontal plane (ɳ). The relationship between these parameters and metering performance could be described by a second-order polynomial equation, and the best metering performance occurred when L=25.3 mm, δ=23.6°, L1=8.1 mm and ɳ=8.3°. The bench test results showed that the GG meter designed with these optimal design parameters had metering performance values (quality index) of 93% and higher over planter travel speeds of 8 to 15 km h-1. In addition, the coefficients of variation of metering performance over the range of planter travel speeds were lower than 30%.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"17 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":"88733908","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}

{"title":"Comparison of Machine Learning Methods for Leaf Nitrogen Estimation in Corn Using Multispectral UAV Images","authors":"Razieh Barzin, G. Bora","doi":"10.13031/TRANS.14305","DOIUrl":"https://doi.org/10.13031/TRANS.14305","url":null,"abstract":"HighlightsLeaf nitrogen percentage in corn was estimated using various vegetation indices derived from UAVs.Eight machine learning methods were compared to find the most accurate model for nitrogen estimation.The most influential vegetation indices were determined for estimation of leaf nitrogen.Abstract. Nitrogen (N) is the most critical component of healthy plants. It has a significant impact on photosynthesis and plant reproduction. Physicochemical characteristics of plants such as leaf N content can be estimated spatially and temporally because of the latest developments in multispectral sensing technology and machine learning (ML) methods. The objective of this study was to use spectral data for leaf N estimation in corn to compare different ML models and find the best-fitted model. Moreover, the performance of vegetation indices (VIs) and spectral wavelengths were compared individually and collectively to determine if combinations of VIs substantially improved the results as compared to the original spectral data. This study was conducted at a Mississippi State University corn field that was divided into 16 plots with four different N treatments (0, 90, 180, and 270 kg ha-1). The bare soil pixels were removed from the multispectral images, and 26 VIs were calculated based on five spectral bands: blue, green, red, red-edge, and near-infrared (NIR). The 26 VIs and five spectral bands obtained from a red-edge multispectral sensor mounted on an unmanned aerial vehicle (UAV) were analyzed to develop ML models for leaf %N estimation of corn. The input variables used in these models had the most impact on chlorophyll and N content and high correlation with leaf N content. Eight ML algorithms (random forest, gradient boosting, support vector machine, multi-layer perceptron, ridge regression, lasso regression, and elastic net) were applied to three different categories of variables. The results show that gradient boosting and random forest were the best-fitted models to estimate leaf %N, with about an 80% coefficient of determination for the different categories of variables. Moreover, adding VIs to the spectral bands improved the results. The combination of SCCCI, NDRE, and red-edge had the largest coefficient of determination (R2) in comparison to the other categories of variables used to predict leaf %N content in corn. Keywords: Corn, Gradient boosting, Machine learning, Multispectral imagery, Nitrogen estimation, Random forest, UAV, Vegetation index.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"30 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81368931","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}

{"title":"Numerical Simulation of the Placement of Exhaust Fans in a Tunnel-Ventilated Layer House During the Fall","authors":"Xiaoshuai Wang, Jiangong Li, Jiegang Wu, Qianying Yi, Xin-lei Wang, Kaiying Wang","doi":"10.13031/TRANS.14657","DOIUrl":"https://doi.org/10.13031/TRANS.14657","url":null,"abstract":"HighlightsThe placement and operation of exhaust fans was assessed using CFD simulation.The effective temperature was used to evaluate the indoor thermal environment.The placement and operation of the exhaust fans mainly affected the airflow patterns in the part of the layer house closest to the fans.Abstract. The thermal environment inside a layer house significantly affects the growth, production, and health of the hens. Tunnel ventilation systems have been widely applied to control the indoor climate and air quality for large-scale poultry facilities around the world. Generally, only a few of the exhaust fans operate during mild seasons (spring and fall) in a tunnel-ventilated layer house depending on the outside air temperature. The decision about which exhaust fans to turn on affects the indoor airflow pattern and temperature distribution. However, little research has been reported that investigated the effects of the locations of exhaust fans on ventilation performance. In this study, a computational fluid dynamics (CFD) model was built and validated using field-measured data. The CFD model was then used to evaluate different ventilation strategies (combinations of exhaust fans) in a typical tunnel-ventilated layer house during the fall. The effective temperature was used to assess the performance of different ventilation strategies. Results showed that the locations of the exhaust fans significantly affected the indoor thermal environment, especially in the part of the house closest to the fans, because different locations of operating fans can generate different airflow patterns and affect the airflow through the animal-occupied zone. Based on the simulations, we conclude that the placement and operation of the exhaust fans can be optimized. Turning on the fans that are lower to the ground or near the sidewalls will result in more air bypassing the animal-occupied zones. Our results can help select the best ventilation strategy during the spring and fall in layer houses with tunnel ventilation systems. Keywords: Airflow distribution, Effective temperature distribution, Indoor thermal environments, Ventilation strategy.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"30 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73283127","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}

{"title":"BiGRU-Attention Based Cow Behavior Classification Using Video Data for Precision Livestock Farming","authors":"Yangyang Guo, Yongliang Qiao, S. Sukkarieh, L. Chai, Dongjian He","doi":"10.13031/trans.14658","DOIUrl":"https://doi.org/10.13031/trans.14658","url":null,"abstract":"HighlightsBiGRU-attention based cow behavior classification was proposed.Key spatial-temporal features were captured for behavior representation.BiGRU-attention achieved >82% classification accuracy on calf and adult cow datasets.The proposed method could be used for similar animal behavior classification.Abstract. Animal behavior consists of time series activities, which can reflect animals’ health and welfare status. Monitoring and classifying animal behavior facilitates management decisions to optimize animal performance, welfare, and environmental outcomes. In recent years, deep learning methods have been applied to monitor animal behavior worldwide. To achieve high behavior classification accuracy, a BiGRU-attention based method is proposed in this article to classify some common behaviors, such as exploring, feeding, grooming, standing, and walking. In our work, (1) Inception-V3 was first applied to extract convolutional neural network (CNN) features for each image frame in videos, (2) bidirectional gated recurrent unit (BiGRU) was used to further extract spatial-temporal features, (3) an attention mechanism was deployed to allocate weights to each of the extracted spatial-temporal features according to feature similarity, and (4) the weighted spatial-temporal features were fed to a Softmax layer for behavior classification. Experiments were conducted on two datasets (i.e., calf and adult cow), and the proposed method achieved 82.35% and 82.26% classification accuracy on the calf and adult cow datasets, respectively. In addition, in comparison with other methods, the proposed BiGRU-attention method outperformed long short-term memory (LSTM), bidirectional LSTM (BiLSTM), and BiGRU. Overall, the proposed BiGRU-attention method can capture key spatial-temporal features to significantly improve animal behavior classification, which is favorable for automatic behavior classification in precision livestock farming. Keywords: BiGRU, Cow behavior, Deep learning, LSTM, Precision livestock farming.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"178 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75446295","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}

{"title":"Base Cutting Energy Consumption for Sugarcane Stools Using Contra-Rotating Basecutters","authors":"Fenglei Wang, Shaochun Ma, Haonan Xing, Jing Bai, Jinzhi Ma, Yezhen Yang, Jiwei Hu","doi":"10.13031/TRANS.13997","DOIUrl":"https://doi.org/10.13031/TRANS.13997","url":null,"abstract":"HighlightsThis study focused on the base cutting energy consumption for sugarcane stools instead of single stalks, thus being more consistent with actual field harvesting.The energy consumption increased with increasing rotational speed (RS) and stool diameter (SD), while it decreased with increasing tilt angle (TA) and feed rate (FR).Each pair of levels of each factor was compared using Duncan’s multiple range test. Three factors (RS, SD, and FR) had significant effects on energy consumption at 95% confidence level, while one factor (TA) had no significant effect.The order of influence and the optimal combination of the four factors to minimize the energy consumed during base cutting were determined.Abstract. Previous studies on contra-rotating basecutter designs based on supported cutting have mainly focused on the base cutting energy consumption for single sugarcane stalks instead of sugarcane stools. However, in the actual base cutting process, a basecutter typically cuts multiple sugarcane stalks (in one sugarcane stool) simultaneously. Therefore, this study investigated how the rotational speed (RS) and tilt angle (TA) of the cutting discs, the sugarcane stool diameter (SD), and the feed rate (FR) affected the energy consumed when cutting cane stools using a contra-rotating cutting platform. Four single-factor experiments and an orthogonal experiment were performed using a Taguchi orthogonal experimental design, and each group was replicated five times. The results of the single-factor experiments showed that the energy consumption was proportional to RS and SD, while it was negatively correlated with TA and FR. The significance of the difference between each pair of levels of each factor was investigated using Duncan’s multiple range test. According to the results of the orthogonal experiment, RS, SD, and FR had significant influences on the base cutting energy consumption at the 95% confidence level; however, TA had no significant influence. The order of influence of the four factors was SD > FR > RS > TA (18.45 > 18.39 > 12.91 > 9.06), and the optimal factor-level combination for minimizing the cutting energy was RS2, TA4, SD1, and FR3 (200 rpm disc RS, 20° disc TA, 60 mm SD, and 1.0 m s-1 FR). An understanding of the relationships between energy consumption and its influencing factors can serve as a valuable reference for researchers seeking to optimize the design of contra-rotating basecutters, which could lead to increased energy efficiency and a reduction in energy consumption during sugarcane harvesting. Keywords: Contra-rotating basecutter, Energy consumption, Orthogonal experiment, Single-factor experiment, Sugarcane stools, Supported cutting.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"59 1","pages":"221-230"},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88024654","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}

{"title":"Nozzle Flow Rate, Pressure Drop, and Response Time of Pulse Width Modulation (PWM) Nozzle Control Systems","authors":"J. Fabula, A. Sharda, Qing Kang, D. Flippo","doi":"10.13031/TRANS.14360","DOIUrl":"https://doi.org/10.13031/TRANS.14360","url":null,"abstract":"HighlightsNozzle pressure drop varies between PWM systems at different application rates and application pressures.Change in flow rate with respect to the expected flow differs between PWM systems at different rates and pressures.There was a latency before the system reached the target application pressure.PWM systems operate for less time than the specified duty cycle, which may cause application errors.Abstract. Three PWM nozzle control systems, Capstan PinPoint II, John Deere ExactApply, and Raven Hawkeye, referred to as systems S1, S2, and S3, respectively, were used in this study. Data on nozzle pressure, boom pressure, flow rate, and response time were recorded with different duty cycles (25%, 50%, 75%, and 100%) and operating frequencies (10, 15, and 30 Hz) for two application rates (112.2 and 187.1 L ha-1) and two application pressures (275.8 and 448.2 kPa) at 1 kHz using a LabVIEW program and a cRIO data acquisition system. Results indicated that the PWM systems perform differently when operating at different application rates, pressures, duty cycles, and frequencies. Each PWM system provided a different pressure drop at the nozzle during operation. The increase in application rate and pressure increased the pressure drop. The percent change in flow rate with respect to the expected flow was also significantly different between the PWM systems, which could be due to the differences in pressure provided at the nozzle during operation. The PWM systems also showed latency before reaching the target application pressure during operation and operated for less time than the specified duty cycle at stable target pressure while also continuing to spray even after the solenoid valves had closed. The application pressure during peak and fall times and the time of stable application pressure within a cycle should be given careful consideration when selecting a PWM system, as they can contribute to application errors. Producers should also consider the pressure drop with the selected PWM system and target application rate to set up the system to apply at the desired pressure. Manufacturers mostly recommend operating PWM systems at 10 Hz. For the purpose of this study, the operating frequency of the PWM systems was set to 10 and 15 Hz for S1, to 15 and 30 Hz for S2, and to 10, 15, and 30 Hz for S3. Producers should expect differences in pressure drop, stabilized pressure application time, and flow rate if they choose to operate at a higher frequency. The results of this study are only applicable to the types of nozzle bodies and nozzle tips used. The data will differ based on the dual-orifice valve coefficient equation: the larger the second orifice, the greater the pressure drop. This will affect the final orifice pressure, as well as the flow rate. This study did not address the impact of flow resistance caused by differences in the design of nozzle bodies and nozzle types. Keywords: Nozzle flow rate, Pressure drop, Pulse width modulation control m","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"13 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80655753","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}

{"title":"Modeling the Effects of Crop Rotation and Tillage on Sugarbeet Yield and Soil Nitrate Using RZWQM2","authors":"M. J. Anar, Zhulu Lin, Liwang Ma, A. Chatterjee","doi":"10.13031/TRANS.13752","DOIUrl":"https://doi.org/10.13031/TRANS.13752","url":null,"abstract":"HighlightsFour crop growth modules in RZWQM2 were calibrated for four sugarbeet rotation sequences.Sugarbeet following wheat had a slightly higher yield (3% to 6.5%).Moldboard plow increased sugarbeet yield by 1% to 2%.The difference in N losses under different crop rotations and tillage operations was negligible.Abstract. Sugarbeet (Beta vulgaris) is considered to be one of the most viable alternatives to corn for biofuel production as it may be qualified as the feedstock for advanced biofuels (reducing greenhouse gas emission by 50%) under the Energy Independence and Security Act (EISA) of 2007. Because sugarbeet production is affected by crop rotation and tillage through optimal use of soil water and nutrients, simulation of these effects will help in making proper management decisions. In this study, the CSM-CERES-Beet, CSM-CERES-Maize, CROPSIM-Wheat, and CROPGRO-Soybean models included in the RZWQM2 were calibrated against experimental field data of crop yield, soil water, and soil nitrate from the North Dakota State University Carrington Research Extension Center from 2014 to 2016. The models performed reasonably well in simulating crop yield, soil water, and nitrate (rRMSE = 0.055 to 2.773, d = 0.541 to 0.997). Simulation results identified a non-significant effect of crop rotation on sugarbeet yield, although sugarbeets following wheat resulted in 3% to 6.5% higher yields compared to other crops. Net mineralization and N uptake rates were slightly higher when sugarbeets followed wheat compared to the other crops. Seasonal N and water mass balances also showed lower N and water stresses when sugarbeets followed wheat. The effects of tillage operations on sugarbeet yield were also non-significant. The difference in the N losses to runoff and drainage from the sugarbeet fields under different crop rotations and tillage operations was negligible. As sugarbeet production may be expanded into nontraditional planting areas in the Red River Valley due to potential demand for biofuel production, our findings will help to assess the associated environmental impacts and identify suitable crop rotations and management scenarios in the region. Keywords: Biofuel, Crop rotation, RZWQM2, Sugarbeet, Tillage.","PeriodicalId":23120,"journal":{"name":"Transactions of the ASABE","volume":"32 1","pages":"461-474"},"PeriodicalIF":1.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87288146","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}