Toshiki Yoneyama

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Natural abundance of 15N (δ 15N) of leaves harvested from tropical plants in Brazil and Thailand was analyzed. The δ 15N values of non-N2-fixing trees in Brazil were +4.5±1.9‰, which is lower than those of soil nitrogen (+8.0±2.2‰). In contrast, mimosa and kudzu had very low δ 15N values (−1.4≈+0.5‰). The δ 15N values of Panicum maximum and leguminous(More)
The contribution of nitrogen fixation by sugarcane plants grown in the fields at various sites in Brazil, at a few sites in the Philippines and in Miyako Island (Japan) was examined using the difference in natural 15N abundance (δ15N) in the leaves of sugarcane compared to those of neighbouring plants. The sugarcane plants from Três Poutas of Minas Gerais(More)
The leaves and nodules from the shrub and tree legumes, particularly, Aeschynomene spp., Sesbania spp., Mimosa spp. and Leucaena spp., and Casuarina spp. and the leaves from neighbouring non-fixing plants were analyzed for their natural abundances of 15N (δ 15N). The δ 15N in the leaves of non-fixing plants was +5.9% on average, whereas those from shrub(More)
By using the image analyzer technique, the length of rice roots including the fine size (ca. 20 μm) roots was successfully measured. The analysis revealed that the roots of a high-yielding rice variety were 26% longer than those of an ordinary variety and that the root length of both varieties varied similarly depending on the fertilizer managements.
A portable meter for measuring the intensity of the green color of a rice canopy in the field by using spectral reflectance at 550 and 800 nm was newly devised. The measurements were found to be affected by reflection of sunshine on the leaf surface. With such limitations being taken into account, rice canopy green color intensity could be evaluated with(More)
The influence ofKlebsiella oxytoca andEnterobacter cloacae inoculation on dinitrogen fixation by the rice-bacteria association was examined in pots in a greenhouse. For inoculation,K. oxytoca NG13 isolated from a Japan paddy soil,E. cloacae E26 isolated from a China soil and following three strains were employed.K. oxytoca NG1389 is a mutant from NG13 and(More)
We have obtained the first in situ STM molecular image of a CO adlayer on a Pt(110)-(1 x 1) electrode surface in 0.1 M HClO(4) solution. The observed CO adlayer formed an ordered (2 x 1)-2CO structure at saturated coverage. The CO molecules were found to adsorb on top of each Pt surface atom; however, they were tilted with a zigzag configuration along the(More)
In the present study, we have investigated structures of a CO adlayer on a well-defined Pt(100) electrode surface in 0.1 M HClO4 aqueous solutions saturated with N2, 1% CO/He and 100% CO by using in situ STM. The in situ STM images with molecular resolution demonstrated that highly ordered structures of the CO adlayer, denoted (2 × n) - 2(n - 1)CO with CO(More)
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