89 research outputs found
Genotypic differences in soybean yield responses to increasing temperature in a cool climate are related to maturity group
No full textTo adapt soybean production to climate change, a thorough understanding of its response to high temperature is required. Modeling studies have predicted that high temperature would shorten the growth period and hence lower seed yield of less day length-sensitive (early-maturing) soybean cultivars, whereas the magnitude of yield reduction by high temperature would be smaller in cultivars with higher day length sensitivity (late-maturing), suggesting that late-maturing cultivars would benefit from a future high-temperature environment. Current mean growing season temperature ranges from 19.4 to 22.6 degrees C in the northern, cool regions of Japan, which is near or below the reported optimum temperature (22-24 degrees C) for seed yield. We tested the hypothesis that adaptation by growing late-maturing cultivars will be successful in maintaining seed yield under a cool climate when temperature is increased during 21st century. We used three Japanese soybean cultivars, early-maturing Yukihomare and late-maturing cultivars Ryuhou and Enrei. Plants were grown over 3 years from June to September (a conventional season) under three temperature regimes, T1 (ambient), T2 (1.8-3.6 degrees C above ambient), T3 (4.8-5.7 degrees C above ambient), in a sunlit temperature gradient chamber. The leaf area at the full expansion stage, pod and seed numbers, and seed yield increased at elevated temperature in the late-maturing cultivars but not in the early-maturing one. The photosynthetic rate and effective quantum yield of photosystem II at the flowering stage increased at elevated temperature in all three cultivars. The period from sowing to the beginning of flowering (R1) decreased in all three cultivars at elevated temperature, whereas the period from R1 to the beginning of pod addition and the flowering period were prolonged in the late-maturing cultivars, but not in the early-maturing one. The differential response in post-flowering development in different maturity groups is probably related to the differences in the day length requirements of these cultivars. Our data clearly demonstrate that yield enhancement by increasing temperature in the late-maturing cultivars resulted from both the improvement in sources (leaf area and leaf photosynthesis) and the increase in sink size (number of flowers, pods and seeds) due to the longer flowering period. We conclude that the yield of the late-maturing cultivars sown during the conventional season in the cool regions of Japan will increase during the 21st century. (C) 2014 Elsevier B.V. All rights reserved
北海道農業研究センターにおける1966年からの気象観測について
No full textThe National Agricultural Research Center for Hokkaido Region (NARCH) has been recording meteorological data since 1966(Miyata, 1922). The meteorological data are available on NARCH's web site. In this report, the methods used to obtain the data are explained. The meteorological data recorded at NARCH are different from data recorded at more urban observatories because the NARCH data are almost free of urbanization effects (Sameshima et al., 2007). Temperature data recorded at NARCH are therefore typical data for agricultural areas without urbanization effects. Although the NARCH observatory is surrounded by buildings (Fig. 1), NARCH's huge grounds (823 ha) are mostly covered by vegetation (experimental fields and forest), which insulates the observatory from urbanization effects
Exploring Emptiness: An Investigation of MA and MU in My Sonic Composition Practice
No full textThe commentary investigates Japanese aesthetics of space, silence and emptiness - ma and mu - that informed my compositional practice during the research period 2012 - 2015. The portfolio comprises text compositions and sound installations in which forms of micro events and sustained events are employed. Throughout, the emphasis is on my personal engagement with, and manifestation of emptiness that concerns a particular model of listening and perception.
Chapter 1 discusses six primary research areas: ma and mu, material, text, form, listening and perception. Firstly, I introduce ma and mu by examining noh culture and Zeami's teaching of senu hima (where there is no-action) in the context of my personal approaches to music. The following subjects are then used to contextualise my PhD practice by means of examples from various composers and visual artists. Here, these particular and enigmatic concepts are explored through Japanese art as well as Western contemporary works by Alvin Lucier, Eliane Radigue and those of the Wandelweiser collective.
Part 2 provides contextual commentaries on selected compositions from the portfolio that mostly articulate my aesthetics in relation to the topics covered in Chapter 1. koso koso addresses my methodologies to investigate the essence of senu hima, followed by treow that discusses my approach to materials and the importance of space. I move on to grade two and grade two extended in order to examine text scores, and then, look into Espèces d'espaces 03 and 04 as examples of musical forms that I employ.
Finally, listening and perception are investigated through the compositions gnome and con.de.structuring. Throughout, I describe how my works explore emptiness as a result of my particular emphasis on listening over composing
Analysis and Modeling of Dry Matter Production Rate by Soybean Community. Curvilinear Response to Radiation Intensity.
No full textEstimating the Absorptivity of Solar Radiation in Soybean Canopies - for Use in Crop Models.
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Genotypic differences in soybean yield responses to increasing temperature in a cool climate are related to maturity group
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