Estimation of cadmium load on Japanese farmland associated with the application of chemical fertilizers and livestock excreta |
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Authors: | Shin-ichiro Mishima Ryosuke Kimura Tsunehisa Inoue |
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Institution: | 1. Water Quality and Solute Dynamics Group, Department of Environmental Chemistry , National Institute for Agro-Environmental Sciences , Tsukuba, 305-8604, Japan;2. Division of Research Coordination, Department of Research Planning and Coordination, National Institute for Agro-Environmental Sciences , Tsukuba, 305-8604, Japan |
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Abstract: | It is very important to use 15N labeled nitrogen gas (15N2) in studies on biological nitrogen fixation. For example, 15N2 is necessary for direct measurement of the amount of fixed nitrogen, and is useful for studies on the assimilation and transport of fixed nitrogen. However, 15N2 is sometimes troublesome to deal with for the following reasons. Decline in the 15N content of 15N2 gas may occur as a result of contamination with atmospheric N2 during the storage period or application to nitrogen fixing organisms. Also, the 15N2 gas provided commercially in a glass bottle or gas cylinder is technically and economically not convenient for experiments employing small amounts of 15N2. Moreover, purification of 15N2 gas is necessary for biological research, since contamination with the oxidized forms of nitrogen represses biological nitrogen fixation to a certain extent. A simple method for the preparation, purification and storage of 15N2 gas for biological nitrogen fixation studies, was therefore devised. |
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Keywords: | bio-stimulation chlorate decontamination Iongan plantation soils sugar amendment |
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