Pub Date : 2021-01-01DOI: 10.2480/agrmet.d-21-00029
Kota Shimomoto, N. Fujiuchi, N. Takahashi, H. Nishina, K. Inaba, Yayu Romdhonah, K. Takayama
A real-time monitoring system was developed and applied to monitor the time course of photosynthesis and transpiration in fully-grown tomato plants in a semi-commercial greenhouse. The system was based on an open chamber method in which the ventilator airflow rate is an important parameter affecting the environmental factors in the chamber and physiological response of plants enclosed inside the chamber. So, we assumed that the effects of this parameter on these responses should be evaluated for an agricultural production site. In this study, we investigated differences in the environmental factors in the chamber and physiological response of whole-tomato plants obtained from two chambers ( 0.5 m [W] × 1.0 m [D] × 2.2 m [H] ) implemented with a single ventilator ( SV, 0.36 m 3 min - 1 ) or double ventilators ( DV, 0.72 m 3 min - 1 ) . The relative humidity and vapor pressure deficit inside the SV chamber were about 10 % higher and 0.5 kPa lower than those inside the DV chamber because of the difference in air exchange rates. However, we found no significant effect of airflow rate on net photosynthetic rate, transpiration rate and total conductance of the plants in the SV and DV chambers by analyzing with weighted Deming regression. This simultaneous monitoring method, undertaken in multiple chambers, and weighted Deming regression analysis can be used to check whether measurement conditions are appropriate for on-site monitoring.
开发了一种实时监测系统，并应用于半商业化温室番茄植株光合和蒸腾作用的实时监测。该系统采用开室法，通风机的风量是影响室内环境因素和室内植物生理反应的重要参数。因此，我们假设该参数对这些响应的影响应该对农业生产场地进行评估。在本研究中，我们研究了在单通气机(SV, 0.36 m 3 min - 1)和双通气机(DV, 0.72 m 3 min - 1)的两个通气机(0.5 m [W] × 1.0 m [D] × 2.2 m [H])中获得的番茄植株在室内环境因子和生理反应上的差异。由于空气交换速率的差异，SV室内的相对湿度和蒸汽压差比DV室内高约10%，低约0.5 kPa。然而，通过加权Deming回归分析，我们发现气流速率对SV和DV室内植物的净光合速率、蒸腾速率和总导度没有显著影响。这种多室同时监测的方法，通过加权Deming回归分析，可以检验测量条件是否适合现场监测。
{"title":"Comparison of photosynthetic rates, transpiration rates, and total conductance of greenhouse-grown tomato plants measured with two open chambers with different ventilation rates","authors":"Kota Shimomoto, N. Fujiuchi, N. Takahashi, H. Nishina, K. Inaba, Yayu Romdhonah, K. Takayama","doi":"10.2480/agrmet.d-21-00029","DOIUrl":"https://doi.org/10.2480/agrmet.d-21-00029","url":null,"abstract":"A real-time monitoring system was developed and applied to monitor the time course of photosynthesis and transpiration in fully-grown tomato plants in a semi-commercial greenhouse. The system was based on an open chamber method in which the ventilator airflow rate is an important parameter affecting the environmental factors in the chamber and physiological response of plants enclosed inside the chamber. So, we assumed that the effects of this parameter on these responses should be evaluated for an agricultural production site. In this study, we investigated differences in the environmental factors in the chamber and physiological response of whole-tomato plants obtained from two chambers ( 0.5 m [W] × 1.0 m [D] × 2.2 m [H] ) implemented with a single ventilator ( SV, 0.36 m 3 min - 1 ) or double ventilators ( DV, 0.72 m 3 min - 1 ) . The relative humidity and vapor pressure deficit inside the SV chamber were about 10 % higher and 0.5 kPa lower than those inside the DV chamber because of the difference in air exchange rates. However, we found no significant effect of airflow rate on net photosynthetic rate, transpiration rate and total conductance of the plants in the SV and DV chambers by analyzing with weighted Deming regression. This simultaneous monitoring method, undertaken in multiple chambers, and weighted Deming regression analysis can be used to check whether measurement conditions are appropriate for on-site monitoring.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170463","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}
Pub Date : 2021-01-01DOI: 10.2480/AGRMET.D-20-00013
L. Sha, Munemasa Teramoto, N. Noh, S. Hashimoto, Meng Yang, Montri Sanwangsri, N. Liang
Soil respiration (Rs) is the largest flux of carbon dioxide (CO2) next to photosynthesis in terrestrial ecosystems. With the absorption of atmospheric methane (CH4), upland soils become a large CO2 source and CH4 sink. These soil carbon (C) fluxes are key factors in the mitigation and adaption of future climate change. The Asian region spans an extensive area from the northern boreal to tropical regions in Southeast Asia. As this region is characterised by highly diverse ecosystems, it is expected to experience the strong impact of ecosystem responses to global climate change. For the past two decades, researchers in the AsiaFlux community have meaningfully contributed to improve the current understanding of soil C dynamics, response of soil C fluxes to disturbances and climate change, and regional and global estimation based on model analysis. This review focuses on five important aspects: 1) the historical methodology for soil C flux measurement; 2) responses of soil C flux components to environmental factors; 3) soil C fluxes in typical ecosystems in Asia; 4) the influence of disturbance and climate change on soil C fluxes; and 5) model analysis and the estimation of soil C fluxes in research largely focused in Asia.
{"title":"Soil carbon flux research in the Asian region: Review and future perspectives","authors":"L. Sha, Munemasa Teramoto, N. Noh, S. Hashimoto, Meng Yang, Montri Sanwangsri, N. Liang","doi":"10.2480/AGRMET.D-20-00013","DOIUrl":"https://doi.org/10.2480/AGRMET.D-20-00013","url":null,"abstract":"Soil respiration (Rs) is the largest flux of carbon dioxide (CO2) next to photosynthesis in terrestrial ecosystems. With the absorption of atmospheric methane (CH4), upland soils become a large CO2 source and CH4 sink. These soil carbon (C) fluxes are key factors in the mitigation and adaption of future climate change. The Asian region spans an extensive area from the northern boreal to tropical regions in Southeast Asia. As this region is characterised by highly diverse ecosystems, it is expected to experience the strong impact of ecosystem responses to global climate change. For the past two decades, researchers in the AsiaFlux community have meaningfully contributed to improve the current understanding of soil C dynamics, response of soil C fluxes to disturbances and climate change, and regional and global estimation based on model analysis. This review focuses on five important aspects: 1) the historical methodology for soil C flux measurement; 2) responses of soil C flux components to environmental factors; 3) soil C fluxes in typical ecosystems in Asia; 4) the influence of disturbance and climate change on soil C fluxes; and 5) model analysis and the estimation of soil C fluxes in research largely focused in Asia.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170118","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}
Pub Date : 2021-01-01DOI: 10.2480/AGRMET.D-20-00019
N. Dahal, Dong-hong Xiong, Nilhari Neupane, Bao-jun Zhang, Bin-tao Liu, Yong Yuan, Yi-ping Fang, S. Koirala, M. Rokaya
Crop yield is mainly affected by climatic factors such as temperature and precipitation. Besides these factors, improved seeds, irrigation access, and fertilizers also affect yield. In the present study, we collected crop yield data for major crops such as maize, rice, and wheat from the Koshi River Basin, Nepal. We investigated the yield trends over 30 years ( 1987 ‑ 2016 ) and related the yields with climatic factors ( temperature and precipitation ) . We also investigated the trends in the use of improved seeds, irrigation access, and fertilizer use in our study area. Results showed that there was an increase in yield of maize, rice, and wheat over 30‑year period. Maize yield slightly increased with increasing average temperature. Rice yields significantly decreased with increasing temperature and precipitation, whereas wheat yield increased with increasing the diurnal temperature range. The present study suggests that future yields of maize, rice, and wheat will be affected by the increasing temperature than precipitation in the Koshi River Basin, Nepal.
{"title":"Factors affecting maize, rice and wheat yields in the Koshi River Basin, Nepal","authors":"N. Dahal, Dong-hong Xiong, Nilhari Neupane, Bao-jun Zhang, Bin-tao Liu, Yong Yuan, Yi-ping Fang, S. Koirala, M. Rokaya","doi":"10.2480/AGRMET.D-20-00019","DOIUrl":"https://doi.org/10.2480/AGRMET.D-20-00019","url":null,"abstract":"Crop yield is mainly affected by climatic factors such as temperature and precipitation. Besides these factors, improved seeds, irrigation access, and fertilizers also affect yield. In the present study, we collected crop yield data for major crops such as maize, rice, and wheat from the Koshi River Basin, Nepal. We investigated the yield trends over 30 years ( 1987 ‑ 2016 ) and related the yields with climatic factors ( temperature and precipitation ) . We also investigated the trends in the use of improved seeds, irrigation access, and fertilizer use in our study area. Results showed that there was an increase in yield of maize, rice, and wheat over 30‑year period. Maize yield slightly increased with increasing average temperature. Rice yields significantly decreased with increasing temperature and precipitation, whereas wheat yield increased with increasing the diurnal temperature range. The present study suggests that future yields of maize, rice, and wheat will be affected by the increasing temperature than precipitation in the Koshi River Basin, Nepal.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170197","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}
Pub Date : 2021-01-01DOI: 10.2480/AGRMET.D-20-00042
T. Hidayat, Y. Koesmaryono, I. Impron, M. Ghulamahdi
This study was conducted to analyze the effectiveness of using reflective mulch under the stands of oil palm plants of several ages on the intensity of solar radiation reflection, growth, chlorophyll content, and photosynthetic characteristics of soybeans. A nested design was used, with the first factor of oil palm age group consisting of open land and land under oil palm stands aged 4, 5, and 8 years. The second factor was the reflective mulch that included land without mulch, land with inorganic reflective mulch, and land with organic reflective mulch. The use of reflective mulch in the soybean - oil palm intercropping system was able to increase the reflection intensity of surface solar radiation, as well as increase the soybean solar radiation interception. The use of inorganic and organic reflective mulch significantly increased the leaf area, specific leaf weight, and soybean stomatal density. Organic reflective mulch led to significant reductions in the amount of chlorophyll A and B content. The photosynthetic rate of soybean in lower leaves was increased significantly. Inorganic reflective mulch resulted in significant reductions in the rate of transpiration, intercellular CO 2 concentration, and conductance of soybean stomata in lower leaves. The use of reflective mulch contributed to improved soybean performance under oil palm stands. The use of organic reflective mulch for soybean grown under oil palm stands aged up to 5 years resulted in better growth rates due to the increased intensity of solar radiation reflected from the surface. However, the reflection effect could not meet the needs of soybean solar radiation on land under oil palm stands aged >5 years due to the very low transmission. Therefore, the use of organic reflective mulch is more effective and efficient in the soybean - oil palm intercropping system until the oil palm reaches the age of 5 years.
{"title":"The effectiveness of reflective mulch in the intercropping system between soybean and oil palm: effects on growth, chlorophyll content, and photosynthetic characteristics","authors":"T. Hidayat, Y. Koesmaryono, I. Impron, M. Ghulamahdi","doi":"10.2480/AGRMET.D-20-00042","DOIUrl":"https://doi.org/10.2480/AGRMET.D-20-00042","url":null,"abstract":"This study was conducted to analyze the effectiveness of using reflective mulch under the stands of oil palm plants of several ages on the intensity of solar radiation reflection, growth, chlorophyll content, and photosynthetic characteristics of soybeans. A nested design was used, with the first factor of oil palm age group consisting of open land and land under oil palm stands aged 4, 5, and 8 years. The second factor was the reflective mulch that included land without mulch, land with inorganic reflective mulch, and land with organic reflective mulch. The use of reflective mulch in the soybean - oil palm intercropping system was able to increase the reflection intensity of surface solar radiation, as well as increase the soybean solar radiation interception. The use of inorganic and organic reflective mulch significantly increased the leaf area, specific leaf weight, and soybean stomatal density. Organic reflective mulch led to significant reductions in the amount of chlorophyll A and B content. The photosynthetic rate of soybean in lower leaves was increased significantly. Inorganic reflective mulch resulted in significant reductions in the rate of transpiration, intercellular CO 2 concentration, and conductance of soybean stomata in lower leaves. The use of reflective mulch contributed to improved soybean performance under oil palm stands. The use of organic reflective mulch for soybean grown under oil palm stands aged up to 5 years resulted in better growth rates due to the increased intensity of solar radiation reflected from the surface. However, the reflection effect could not meet the needs of soybean solar radiation on land under oil palm stands aged >5 years due to the very low transmission. Therefore, the use of organic reflective mulch is more effective and efficient in the soybean - oil palm intercropping system until the oil palm reaches the age of 5 years.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170294","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}
The statistical characteristics of 1789 deaths, 1552 injuries and 1904 disasters caused by lightning based on the 2009 to 2018 National Lightning Disaster Compilation of mainland China were analyzed. The results showed that males accounted for 53 % of casualties. Lightning disasters were more common in the east and south than in the west and north. The number of lightning disasters and casualties in the south accounted for 82.98 % and 82.94 % of the totals, respectively. May to August of each year is the intensive period of lightning disasters in China, and the number of deaths, injuries and disasters caused by lightning during these four months accounted for 84.80 % , 79.45 % and 82.77 % of the total numbers per year, respectively. From 2009 to 2018, the annual injury and death rates per million people in China were 0.13 and 0.12, respectively. After population weighting, the high death rate of lightning disaster shows a certain trend of transferring from the concentrated area to the sparsely populated area, after area weighting, the casualty density was higher in small provinces and lower in large provinces . The analysis of the environments in which lightning disaster casualties occurred found that environments closely related to agriculture, such as farmland ( 35 % ) and paddy fields or ponds ( 4 % ) , accounted for nearly 40 % of the casualties; accordingly, rural farmers were the main victims, accounting for 80.96 % of the total casualties. Lightning protection and disaster reduction measures in rural agricultural areas should be the focus of future work.
{"title":"Lightning fatalities in China, 2009-2018","authors":"Yin Qiyuan, Hengyi Liu, Xiangpeng Fan, Yijun Zhang, Zhuang Yanxun, Fei Wang, Hui-ying Du, Huang Xingxing, Shaodong Chen, Chen Lyuwen","doi":"10.2480/AGRMET.D-20-00045","DOIUrl":"https://doi.org/10.2480/AGRMET.D-20-00045","url":null,"abstract":"The statistical characteristics of 1789 deaths, 1552 injuries and 1904 disasters caused by lightning based on the 2009 to 2018 National Lightning Disaster Compilation of mainland China were analyzed. The results showed that males accounted for 53 % of casualties. Lightning disasters were more common in the east and south than in the west and north. The number of lightning disasters and casualties in the south accounted for 82.98 % and 82.94 % of the totals, respectively. May to August of each year is the intensive period of lightning disasters in China, and the number of deaths, injuries and disasters caused by lightning during these four months accounted for 84.80 % , 79.45 % and 82.77 % of the total numbers per year, respectively. From 2009 to 2018, the annual injury and death rates per million people in China were 0.13 and 0.12, respectively. After population weighting, the high death rate of lightning disaster shows a certain trend of transferring from the concentrated area to the sparsely populated area, after area weighting, the casualty density was higher in small provinces and lower in large provinces . The analysis of the environments in which lightning disaster casualties occurred found that environments closely related to agriculture, such as farmland ( 35 % ) and paddy fields or ponds ( 4 % ) , accounted for nearly 40 % of the casualties; accordingly, rural farmers were the main victims, accounting for 80.96 % of the total casualties. Lightning protection and disaster reduction measures in rural agricultural areas should be the focus of future work.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170302","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}
Pub Date : 2021-01-01DOI: 10.2480/AGRMET.D-20-00018
Shih-Chieh Chang, T. Saitoh, H. Shibata, Satoshi N. Suzuki
To elucidate the dynamic features of carbon sequestration in ecosystems under changing climates and various disturbance regimes, researchers must understand key ecosystem processes, such as carbon allocation and partitioning, organic matter decomposition, and nutrient cycles, as well as plant functional traits. Here, we reviewed the existing literature and conducted meta-analyses using available datasets from eddy covariance CO 2 flux sites in East Asia to clarify these ecosystem processes and attributes. Since the establishment of AsiaFlux in 1999, the number of flux tower sites has grown to 110 sites, spanning a large geographic extent in East Asia and covering diverse ecosystems embedded in large climatic gradients. Early publications relating to AsiaFlux described CO 2 fluxes from single sites, but over the last 20 years more ecosystem processes and attributes have been included in the study sites’ research programs. Among other advances, researchers have quantified the plant functional traits related to photosynthesis or ecosystem-scale gross primary production and thus demonstrated that CO 2 fluxes are controlled by plant traits; this quantification provides a basis for building ecosystem models. Additional means of understanding the carbon fluxes and pools of these ecosystems have been provided by biometric measurements beneath eddy covariance flux towers, partly on the basis of traditional forestry practices and the measurements of component carbon fluxes, such as respiratory fluxes and litter decomposition rates. Through meta-analyses, we demonstrate good correlations between these fluxes and mention the characteristics of carbon cycle processes in Asian forest ecosystems. By investigating nitrogen biogeochemical cycles at the flux sites, studies have shown that carbon fluxes are also controlled by nitrogen availability. The future success and progress of AsiaFlux could be promoted by further collaborations between this research community and other networks, such as long-term ecological research ( LTER ) networks, and the development of open databases.
{"title":"Recent advances in the understanding of ecosystem processes at eddy covariance CO2 flux sites in East Asian forest ecosystems: a review","authors":"Shih-Chieh Chang, T. Saitoh, H. Shibata, Satoshi N. Suzuki","doi":"10.2480/AGRMET.D-20-00018","DOIUrl":"https://doi.org/10.2480/AGRMET.D-20-00018","url":null,"abstract":"To elucidate the dynamic features of carbon sequestration in ecosystems under changing climates and various disturbance regimes, researchers must understand key ecosystem processes, such as carbon allocation and partitioning, organic matter decomposition, and nutrient cycles, as well as plant functional traits. Here, we reviewed the existing literature and conducted meta-analyses using available datasets from eddy covariance CO 2 flux sites in East Asia to clarify these ecosystem processes and attributes. Since the establishment of AsiaFlux in 1999, the number of flux tower sites has grown to 110 sites, spanning a large geographic extent in East Asia and covering diverse ecosystems embedded in large climatic gradients. Early publications relating to AsiaFlux described CO 2 fluxes from single sites, but over the last 20 years more ecosystem processes and attributes have been included in the study sites’ research programs. Among other advances, researchers have quantified the plant functional traits related to photosynthesis or ecosystem-scale gross primary production and thus demonstrated that CO 2 fluxes are controlled by plant traits; this quantification provides a basis for building ecosystem models. Additional means of understanding the carbon fluxes and pools of these ecosystems have been provided by biometric measurements beneath eddy covariance flux towers, partly on the basis of traditional forestry practices and the measurements of component carbon fluxes, such as respiratory fluxes and litter decomposition rates. Through meta-analyses, we demonstrate good correlations between these fluxes and mention the characteristics of carbon cycle processes in Asian forest ecosystems. By investigating nitrogen biogeochemical cycles at the flux sites, studies have shown that carbon fluxes are also controlled by nitrogen availability. The future success and progress of AsiaFlux could be promoted by further collaborations between this research community and other networks, such as long-term ecological research ( LTER ) networks, and the development of open databases.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170131","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}
Pub Date : 2021-01-01DOI: 10.2480/AGRMET.D-20-00101
Guirui Yu, T. Hirano
{"title":"Review and future perspective of AsiaFlux","authors":"Guirui Yu, T. Hirano","doi":"10.2480/AGRMET.D-20-00101","DOIUrl":"https://doi.org/10.2480/AGRMET.D-20-00101","url":null,"abstract":"","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"224 1","pages":"1-1"},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170355","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}
Pub Date : 2021-01-01DOI: 10.2480/AGRMET.D-20-00029
T. Tokida
Manually operated closed-chamber methods have been used extensively to measure CH 4 emissions from rice paddies, but the long chamber deployment time ( e.g ., 30 min ) , together with the labor required for gas sampling and subsequent analysis by gas chromatography severely limit their usefulness for multiple, high-throughput measurements. The objective of this study was to develop a modified closed-chamber method suitable for high-throughput measurements. The design of the modified system is based on a conventional method, but uses a portable spectroscopic gas analyzer and a newly developed dehumidification system. Results of a series of test operations showed that the use of a portable gas analyzer substantially reduced the time needed for each chamber deployment to as little as 4–5 min. A simple dehumidification system employing a selective water vapor-permeable tube was introduced to effectively dehumidify the sample gas so that the risk of water condensation was removed without attenuating the CH 4 concentration signal. The chamber must be equipped with a fan to ensure that the chamber air is well mixed and to attain representative CH 4 concentration values. The new method is suitable for high-throughput CH 4 emission measurements and can also be used for studying bubbling CH 4 emissions.
{"title":"Increasing measurement throughput of methane emission from rice paddies with a modified closed-chamber method","authors":"T. Tokida","doi":"10.2480/AGRMET.D-20-00029","DOIUrl":"https://doi.org/10.2480/AGRMET.D-20-00029","url":null,"abstract":"Manually operated closed-chamber methods have been used extensively to measure CH 4 emissions from rice paddies, but the long chamber deployment time ( e.g ., 30 min ) , together with the labor required for gas sampling and subsequent analysis by gas chromatography severely limit their usefulness for multiple, high-throughput measurements. The objective of this study was to develop a modified closed-chamber method suitable for high-throughput measurements. The design of the modified system is based on a conventional method, but uses a portable spectroscopic gas analyzer and a newly developed dehumidification system. Results of a series of test operations showed that the use of a portable gas analyzer substantially reduced the time needed for each chamber deployment to as little as 4–5 min. A simple dehumidification system employing a selective water vapor-permeable tube was introduced to effectively dehumidify the sample gas so that the risk of water condensation was removed without attenuating the CH 4 concentration signal. The chamber must be equipped with a fan to ensure that the chamber air is well mixed and to attain representative CH 4 concentration values. The new method is suitable for high-throughput CH 4 emission measurements and can also be used for studying bubbling CH 4 emissions.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170208","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}
Pub Date : 2021-01-01DOI: 10.2480/agrmet.d-21-00014
R. Matsuda
The effects of continuous lighting (CL) before gene transfer on leaf biomass, leaf hemagglutinin (HA) content per biomass, and leaf HA content per plant in Nicotiana benthamiana after gene transfer were investigated in a transient gene expression system. A control photoperiod of 16 h d and an extended photoperiod of 24 h d were compared at two photosynthetic photon flux density (PPFD) levels of 200 and 400 μmol m s. Leaf biomass was greater in the 24 h d photoperiod treatments and 400 μmol m s PPFD treatments. The leaf HA content per biomass was smaller at 24 h d than at 16 h d, indicating that CL before gene transfer had a negative impact on leaf HA accumulation per biomass after gene transfer. There was no significant difference in leaf HA content per biomass between 200 and 400 μmol m s PPFD. As a result, the leaf HA content per plant was significantly greater in the high PPFD treatments but not significantly different between photoperiod treatments. The results indicate that a simple approach of applying CL before gene transfer increases biomass but not the HA yield and is thus not necessarily cost‐effective in the plant‐based recombinant protein production system.
在瞬时基因表达系统中，研究了基因转移前连续光照(CL)对烟叶生物量、单株血凝素(HA)含量和基因转移后单株HA含量的影响。在200 μmol m s和400 μmol m s的光合光子通量(PPFD)水平下，对照光周期为16 h d和延长光周期为24 h d，叶片生物量在24 h d光周期处理和400 μmol m s PPFD处理下较大。24 h时叶片每生物量HA含量低于16 h时，说明基因转移前的CL对基因转移后叶片每生物量HA积累有负向影响。200 μmol m s PPFD和400 μmol m s PPFD对每生物量叶片HA含量无显著影响。结果表明，高PPFD处理单株叶片HA含量显著高于高PPFD处理，但不同光周期处理间差异不显著。结果表明，在基因转移之前施用CL的简单方法增加了生物量，但不能提高HA产量，因此在基于植物的重组蛋白生产系统中不一定具有成本效益。
{"title":"A 24-h photoperiod before gene transfer promotes biomass production but not the yield of influenza hemagglutinin transiently expressed in Nicotiana benthamiana","authors":"R. Matsuda","doi":"10.2480/agrmet.d-21-00014","DOIUrl":"https://doi.org/10.2480/agrmet.d-21-00014","url":null,"abstract":"The effects of continuous lighting (CL) before gene transfer on leaf biomass, leaf hemagglutinin (HA) content per biomass, and leaf HA content per plant in Nicotiana benthamiana after gene transfer were investigated in a transient gene expression system. A control photoperiod of 16 h d and an extended photoperiod of 24 h d were compared at two photosynthetic photon flux density (PPFD) levels of 200 and 400 μmol m s. Leaf biomass was greater in the 24 h d photoperiod treatments and 400 μmol m s PPFD treatments. The leaf HA content per biomass was smaller at 24 h d than at 16 h d, indicating that CL before gene transfer had a negative impact on leaf HA accumulation per biomass after gene transfer. There was no significant difference in leaf HA content per biomass between 200 and 400 μmol m s PPFD. As a result, the leaf HA content per plant was significantly greater in the high PPFD treatments but not significantly different between photoperiod treatments. The results indicate that a simple approach of applying CL before gene transfer increases biomass but not the HA yield and is thus not necessarily cost‐effective in the plant‐based recombinant protein production system.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170427","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}
Pub Date : 2021-01-01DOI: 10.2480/agrmet.d-20-00024
A. Ito, K. Ichii
A wide variety of models have been developed and used in studies of land - atmosphere interactions and the carbon cycle, with aims of data integration, sensitivity analysis, interpolation, and extrapolation. This review summarizes the achievements of model studies conducted in Asia, a focal region in the changing Earth system, especially collaborative works with the regional flux measurement network, AsiaFlux. Process-based biogeochemical models have been developed to simulate the carbon cycle, and their accuracy has been verified by comparing with carbon dioxide flux data. The development and use of data-driven ( statistical and machine learning ) models has further enhanced the utilization of field survey and satellite remote sensing data. Model intercomparison studies were also conducted by using the AsiaFlux dataset for uncertainty analyses and benchmarking. Other types of models, such as cropland models and trace gas emission models, are also briefly reviewed here. Finally, we discuss the present status and remaining issues in data - model integration, regional synthesis, and future projection with the models.
{"title":"Terrestrial ecosystem model studies and their contributions to AsiaFlux","authors":"A. Ito, K. Ichii","doi":"10.2480/agrmet.d-20-00024","DOIUrl":"https://doi.org/10.2480/agrmet.d-20-00024","url":null,"abstract":"A wide variety of models have been developed and used in studies of land - atmosphere interactions and the carbon cycle, with aims of data integration, sensitivity analysis, interpolation, and extrapolation. This review summarizes the achievements of model studies conducted in Asia, a focal region in the changing Earth system, especially collaborative works with the regional flux measurement network, AsiaFlux. Process-based biogeochemical models have been developed to simulate the carbon cycle, and their accuracy has been verified by comparing with carbon dioxide flux data. The development and use of data-driven ( statistical and machine learning ) models has further enhanced the utilization of field survey and satellite remote sensing data. Model intercomparison studies were also conducted by using the AsiaFlux dataset for uncertainty analyses and benchmarking. Other types of models, such as cropland models and trace gas emission models, are also briefly reviewed here. Finally, we discuss the present status and remaining issues in data - model integration, regional synthesis, and future projection with the models.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170201","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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