Journal of Agricultural Meteorology最新文献

{"title":"Simulating the impacts of and adaptation options for increasing air temperature on chalky rice grains in the Kyushu region of Japan","authors":"Yoshiyuki Kinose, Riku Seita","doi":"10.2480/agrmet.d-22-00017","DOIUrl":"https://doi.org/10.2480/agrmet.d-22-00017","url":null,"abstract":"","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170633","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":"Implications of open circuit voltage of light-emitting diodes installed for plant cultivation","authors":"A. Yano, R. Matsuda, K. Fujiwara","doi":"10.2480/agrmet.d-21-00040","DOIUrl":"https://doi.org/10.2480/agrmet.d-21-00040","url":null,"abstract":"This study investigated a light sensor function of light-emitting diodes (LEDs), the use of which is expanding in plant cultivations. Unimodal spectral LEDs of four types with respective emission peak wavelengths of 464, 501, 634, and 849 nm, and a white LED with a bimodal spectrum with 455-nm primary and 574-nm secondary peaks were used for this study. Open circuit voltage (VOC) of up to 1-2 V was induced in the LEDs when they were irradiated with sunlight. The VOC value of the 634 nm LED saturated with a low photon flux density can be used for binary discrimination between daylight and night. Each LED had a VOC inducible threshold wavelength of incident light. By virtue of the wavelength threshold feature, existence of a plant leaf between a light source and the LEDs is detectable by comparing the VOC values of blue-green range LEDs (464 nm, 501 nm) and near-infrared (NIR) LEDs (849 nm). Under leaf shadow, the NIR LED VOC exceeded those of the blue-green range LEDs. Under natural incident sunlight, the VOCs of the blue-green range LEDs were greater than that of the NIR LED. Another function of LEDs in agricultural use has been demonstrated.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170578","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":"Quantifying bubbling emission (ebullition) of methane from a rice paddy using high-time-resolution concentration data obtained during a closed-chamber measurement","authors":"Masako KAJIURA, Takeshi TOKIDA","doi":"10.2480/agrmet.d-21-00022","DOIUrl":"https://doi.org/10.2480/agrmet.d-21-00022","url":null,"abstract":"Methane (CH₄) produced in rice-paddy soil is transported to the atmosphere either via the rice plants or by bubbling events (ebullition); however, little is known about the frequency and intensity of bubbling CH₄ emissions and the factors that affect them. We developed a method to quantify ebullition using high-time-resolution (~1 Hz) CH₄ concentration data obtained by closed-chamber measurements. Field measurements were conducted in a Japanese rice paddy at different rice growth stages: panicle formation (PF), booting (BT), and heading (HD). A dataset of 132 chamber measurements was used to develop and evaluate the method. A scripting file written in R programing language was used to automatically determine CH₄ emissions via the two pathways. Plant-mediated CH₄ emission intensity was constant during chamber deployment and was reflected as a steady linear increase in chamber [CH₄] with time or as a constant baseline in a flux time series. We found that the plant-mediated emission could be determined as the peak with the lowest flux intensity in the flux frequency distribution even if bubbling events occurred during the chamber deployment. The field measurement results in combination with established data processing protocols showed that at PF, ebullition contributed only 4% of the total emission, whereas it accounted for 32% and 60% of the total emission at BT and HD, respectively. In contrast, the plant-mediated flux variation among growth stages was smaller. Both ebullition and plant-mediated emissions correlated significantly with air temperature at HD, but the magnitude of the dependency was much higher for ebullition than for rice-mediated emission. These results demonstrate that ebullition occurs more frequently than has previously been thought, and the different transport pathways show varying degrees of dependency on plant phenological and environmental factors, thus underscoring the need to separately determine CH₄ emissions via each transport pathway.\u0000</p>","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"29 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138542025","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":"Appropriate chamber deployment time for separate quantification of CH4 emissions via plant and ebullition from rice paddies using a modified closed-chamber method","authors":"M. Kajiura, T. Tokida","doi":"10.21203/rs.3.rs-632766/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-632766/v1","url":null,"abstract":"\u0000 A modified closed-chamber method for estimating total, plant-mediated, and bubbling (ebullition) emissions of CH4 from rice paddies has been developed to use high-time-resolution CH4 concentration data (~ 1 Hz) obtained by a spectroscopic mobile gas analyzer. Here we aimed at determining an appropriate minimum time length of chamber closure for accurate flux measurement by investigating 3255 datasets obtained from a 2-year field survey. To investigate the minimum time length for each chamber measurement, we generated a series of datasets from each measurement: by setting the hypothetical termination time of the chamber closure ahead in 1-min intervals, we obtained various chamber CH4 concentration time series with different durations of chamber closure, and separately estimated CH4 emissions via rice plants and bubbling from each. The estimated flux was sensitive to time length with short closure times, but became less sensitive with longer closure. We defined the minimum time length at which the difference in estimated flux between adjacent time windows was small enough (< 10% of plant-mediated emission). The estimated minimum time length differed from one measurement to another, but 10 min was sufficient for > 99% of cases. Detailed analysis showed a positive correlation between minimum time length and frequency of bubbling events; the time length needed to be longer as bubbling events became more frequent. From this relationship, we computed the appropriate chamber-duration time as a function of bubbling frequency. In the absence of ebullition, 4–5 min was sufficient, but as the bubbling frequency increased to 2.5 times per minute 15–20 min was necessary for accurate pathway-dependent flux measurements.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42049238","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":"Spring onsets of a young forest in interior Alaska determined based on time‑lapse camera and eddy covariance measurements","authors":"Shihori Kawashima, M. Ueyama, Mikita Okamura, Y. Harazono, H. Iwata, Hideki Kobayashi","doi":"10.2480/AGRMET.D-21-00003","DOIUrl":"https://doi.org/10.2480/AGRMET.D-21-00003","url":null,"abstract":"Spring phenology is essential in modeling the carbon balance of high‑latitude ecosystems and is possibly sensitive to climate change. In the present study, we evaluated the onset of the growing season for three species ( paper birch, bog blueberry, and bog Labrador tea ) in interior Alaska from 2012 to 2019 using photos taken using time‑lapse cameras. We also evaluated the onset of the growing season at the ecosystem scale from 2010 to 2019 on the basis of the CO 2 flux by the eddy covariance method at the site. On the basis of the growing degree‑day ( GDD ) model with the parameters estimated using the Bayesian approach, we found that the interannual variations in the spring onsets were explained by the model, and the thermal forcing requirement differed among the species. At the ecosystem scale, the spring onset was closely linked to the snow disappearance date. Under the possible future climate scenarios indicated by the representative concentration pathway 8.5 scenario, the spring onsets were predicted to be one to three weeks earlier than the present dates for the three species. The ecosystem‑scale onsets were also predicted to be five days to a little over a month earlier at the end of this century. The future spring onset is highly sensitive to the snow disappearance date for high‑latitude vegetation; thus, further understanding of climate change before snowmelting is required.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":" ","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48741533","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":"Quantifying bubbling emission (ebullition) of methane from a rice paddy using high-time-resolution concentration data obtained during a closed-chamber measurement","authors":"M. Kajiura, T. Tokida","doi":"10.21203/RS.3.RS-396475/V1","DOIUrl":"https://doi.org/10.21203/RS.3.RS-396475/V1","url":null,"abstract":"\u0000 Methane (CH4) produced in rice-paddy soil is transported to the atmosphere either via the rice plants or by bubbling events (ebullition); however, little is known about the frequency and intensity of bubbling CH4 emissions and the factors that affect them. We developed a method to quantify ebullition using high-time-resolution (~1 Hz) CH4 concentration data obtained by closed-chamber measurements. Field measurements were conducted in a Japanese rice paddy at different rice growth stages: panicle formation (PF), booting (BT), and heading (HD). A dataset of 132 chamber measurements was used to develop and evaluate the method. A scripting file written in R programing language was used to automatically determine CH4 emissions via the two pathways. Plant-mediated CH4 emission intensity was constant during chamber deployment and was reflected as a steady linear increase in chamber [CH4] with time or as a constant baseline in a flux time series. We found that the plant-mediated emission could be determined as the peak with the lowest flux intensity in the flux frequency distribution even if bubbling events occurred during the chamber deployment. The field measurement results in combination with established data processing protocols showed that at PF, ebullition contributed only 4% of the total emission, whereas it accounted for 32% and 60% of the total emission at BT and HD, respectively. In contrast, the plant-mediated flux variation among growth stages was smaller. Both ebullition and plant-mediated emissions correlated significantly with air temperature at HD, but the magnitude of the dependency was much higher for ebullition than for rice-mediated emission. These results demonstrate that ebullition occurs more frequently than has previously been thought, and the different transport pathways show varying degrees of dependency on plant phenological and environmental factors, thus underscoring the need to separately determine CH4 emissions via each transport pathway.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"1 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41349511","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":"Variations in biomass, production and respiration of fine roots in a young larch forest","authors":"Rui Cui, T. Hirano, Lifei Sun, Munemasa Teramoto, N. Liang","doi":"10.2480/AGRMET.D-20-00049","DOIUrl":"https://doi.org/10.2480/AGRMET.D-20-00049","url":null,"abstract":"Root respiration ( R r ) plays a crucial role in the global carbon balance, because R r accounts for about a half of soil respiration in typical forest ecosystems. Plant roots are different in metabolism and functions according to size. Fine roots, which are typically defined as roots < 2 mm in diameter, perform important ecosystem functions and consequently govern belowground carbon cycles mainly because of their high turnover rates. However, the phenological variation of fine root functions is not well understood yet. To quantitatively examine the fine root functions, we adopted an approach to partition R r into growth respiration ( R g ) and maintenance respiration ( R m ) using a modified traditional model, in which R g was proportional to root production, and R m was proportional to root biomass and exponentially related to soil temperature. We conducted a field experiment on soil respiration and fine root biomass and production over a year in a larch-dominated young forest developing on the bare ground after removing surface organic soil to parameterize the model. The model was significantly parameterized using the field data measured in such simplified field conditions, because we could control spatial variation in heterotrophic respiration and contamination from roots other than fine roots. The annual R r of all roots was 94 g C m - 2 yr - 1 and accounted for 25 % of total soil respiration on average. The annual R r was partitioned into fine root R g , fine root R m and coarse root R m by 30, 44 and 26 % , respectively; coarse root R g was presumed to be negligible. Fine root R g and R m varied according to the seasonal variations of fine root production and soil temperature, respectively; the contribution of fine root biomass was minor because of its small seasonality. The contribution of R g to total fine root respiration was lower in the cold season with low production.","PeriodicalId":56074,"journal":{"name":"Journal of Agricultural Meteorology","volume":"18 1","pages":""},"PeriodicalIF":1.3,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69170349","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":"Spatiotemporal distribution of the potential risk of frost damage in tea fields from 1981-2020: A modeling approach considering phenology and meteorology","authors":"Kensuke Kimura, K. Kudo, A. Maruyama","doi":"10.2480/agrmet.d-21-00011","DOIUrl":"https://doi.org/10.2480/agrmet.d-21-00011","url":null,"abstract":"Climate change may induce severe frost damage to crops, and thus a reasonable assessment of frost risk, considering both crop phenology and meteorology, is required. Here, we introduced a new index of potential frost risk ( F risk ) using thermal time ( minimum air temperature below the threshold value ) weighted by the percentage of budburst ( P bud ) . Moreover, we evaluated the spatiotemporal distributions of F risk in tea fields within a 60 km × 60 km area in east Japan from 1981 - 2020, using 1 km 2 -gridded meteorological data and a newly developed model of P bud . The P bud model considered three phenological phases ( endodormancy, ecodormancy, and progress of budburst ) and successfully represented changes in the P bud of the tea buds for 15 years, with root mean square errors of 8.5 percentage points. The spatiotemporal distributions of F risk over the past 40 years showed that potential frost risk significantly increased at elevations ranging from 50 m to 300 m because the budburst advanced at a faster rate than the temperature warming. These elevations corresponded to areas where tea plants were mainly cultivated, which indicates that tea cultivation is becoming vulnerable to frost, and the risk of economic losses due to the frost is increasing. The proposed assessment of frost risk could contribute to predicting frost damage and developing more reliable strategies for the operation of frost protection under the effects of future climate change.","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":"69170386","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":"Field survey on rice spikelet sterility in an extremely hot summer of 2018 in Japan","authors":"M. Yoshimoto, H. Sakai, Y. Ishigooka, T. Kuwagata, T. Ishimaru, H. Nakagawa, A. Maruyama, H. Ogiwara, K. Nagata","doi":"10.2480/agrmet.d-21-00024","DOIUrl":"https://doi.org/10.2480/agrmet.d-21-00024","url":null,"abstract":"In rice (Oryza sativa L.), heat-induced spikelet sterility (HISS) has long been recognized a major threat in the production, and currently the potential risk of yield reduction is likely to be increasing under global warming. However, there have been few studies on HISS conducted under field conditions. In recent years in Japan, extremely high temperatures have frequently recorded in the daytime during the summer. In 2018, heat wave lasted from mid-July to late August, which overlapped the typical rice heading period from eastern to western Honshu and raised a concern about HISS during flowering. To examine this possibility, we surveyed rice sterility in eight prefectures in the Kanto, Tokai, and Kinki regions. During surveys in 2018 and 2019, we collected field data on the sterility of ‘Koshihikari’, the most popular rice variety in Japan, and the sterility ranged from 3.7 to 15.4% in paddy fields. The sterility tended to be higher in the paddy fields where heading occurred during the heat wave. We modeled the sterility rate using the heat dose based on daytime mean panicle temperature, with a threshold for HISS at 33°C. The model estimates based on meteorological data showed that HISS can be induced even under current climatic conditions, depending on the timing of heading. Considering the projected global warming, this study raises an issue that rice plants would face a risk of HISS under the temperate climate in Japan.","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":"69170453","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":"Photosynthetic and respiratory activities of spinach in an unheated greenhouse during winter in Sapporo, Japan","authors":"K. Murakami, T. Hamasaki, M. Nemoto, S. Inoue, T. Hirota","doi":"10.2480/AGRMET.D-20-00033","DOIUrl":"https://doi.org/10.2480/AGRMET.D-20-00033","url":null,"abstract":"Leafy vegetables cultivated in greenhouses during the winter are sometimes exposed to cold air from outside the greenhouse to enhance sugar and nutrient content. To analyze the possible involvement of photosynthetic and respiratory activities in this process, we evaluated the gas-exchange activity of spinach ( Spinacia oleracea L. ) plants cultivated in an unheated greenhouse in mid-winter in Sapporo, where the daily mean air and soil temperatures are approximately - 5 and 0 ° C, respectively. Shoot fresh weight showed little increase, whereas the net leaf photosynthetic rate ( P n ) attained 20 µmol m -2 s -1 and the CO 2 concentration in the greenhouse ( [CO 2 ] ) was sometimes lower than 200 µmol mol -1 , which was suggestive of active photosynthetic CO 2 uptake. After its peak in the morning, P n decreased in the afternoon, presumably owing to ‘midday depression’ caused by suppressed water uptake in the root zone. Observed diurnal [CO 2 ] change was consistent with a significant CO 2 uptake during the daytime. The change also suggested that respiration was active immediately after sunset and suppressed at night. In addition, we calculated the whole-greenhouse CO 2 emission rate ( R ) as a measure of night respiration in the plants, taking into account the air ventilation of the greenhouse. The R value was positive under sub-zero air temperatures in the greenhouse and was positively correlated with the nighttime air and soil temperatures. These experimental data suggest active photosynthesis and respiration of winter-sweetened spinach in the greenhouse, despite the low air and soil temperatures and growth retardation, and implies their involvement in the","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":"69170285","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}