著者

Mamoru Sato Kaori Matsuoka Tsugiko Takase Natsuko I. Kobayashi Hidetoshi Kikunaga Daisuke Takata Keitaro Tanoi Tsutomu Ohtsuki Shinnosuke Kusaba Katsuhiko Yamaguchi

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-006, (Released:2019-01-18)

被引用文献数

8

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We investigated the vertical 137Cs distribution in soil among five sod culture orchards with different soil textures over six years after 2011, when 137Cs fallout was released by the Fukushima Daiichi Nuclear Power Plant accident, to confirm the long-term 137Cs downward-migration into soil. At each orchard, soil cores were collected to a depth of 30 cm and subdivided into intervals of 3 to 9 cm. The 137Cs within the 3 cm of topsoil decreased from 84–94% during the first 7 months after deposition in 2011 to 41–75% in 2017. From 2012 onward, the vertical 137Cs profiles in the soils were explained by a two-component negative exponential model composed of a rapid and a slow component with a change of slope at a depth of 6 to 9 cm. It took 4 years after deposition to show a significant difference in the value of the average 137Cs migration distance (Md) among the orchards. The speed of 137Cs migration in the orchards during the 6 years after the accident year was 0.44 to 0.97 cm year−1 based on the Md. There was a significant positive correlation between Md and fine sand content in the 3 cm of topsoil between Md and the ratio of the total carbon content (TC) at a depth of 3 to 6 cm to that in the top 3 cm of soil. Furthermore, the percentage of exchangeable 137Cs (ex-137Cs) to 137Cs at 3 to 6 cm depth increased significantly in proportion to the ratio of TC at 3 to 6 cm depth to TC at 0 to 3 cm depth in soil collected in 2013. These findings indicate that one of the mobile forms of 137Cs was ex-137Cs combined with TC and that the fine sand content and TC influenced the 137Cs downward-migration in the 3 cm of topsoil in the orchard in which organic matter accumulated by sod culture.

著者

Kaori Matsuoka Naoki Moritsuka Shinnosuke Kusaba Kiyoshi Hiraoka

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-167, (Released:2018-06-13)

被引用文献数

5

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In blueberry culture, when sulfur and NH4+ and K fertilizers are applied to soils, radiocesium in the soils may be released into the soil solution, absorbed by roots, and then translocated to fruit. We reanalyzed data from our previous experiment to evaluate soil factors affecting the concentration and total amount of natural stable Cs in blueberry organs and its translocation to fruit. During a 2-year pot experiment, 4-year-old rabbiteye blueberries (Vaccinium virgatum Aiton ‘Onslow’) were grown in three soils (Andosol, Cambisol, and Fluvisol) with or without soil treatment (acidification, NH4+ and K fertilization, or combined acidification-fertilization treatment). We measured the concentrations of 13 elements (N, Na, Mg, Al, P, K, Ca, Mn, Fe, Cu, Zn, Rb, and Cs) in samples of the soil solution and the blueberry fruit, leaves, branches and stems, and roots, as well as the pH of the soil solution. Acidification, fertilization, and combined treatment increased the Cs concentration in the soil solution within each soil. On the other hand, the Cs concentration in the whole bush was not changed significantly by any soil treatment. The Cs concentration in fruit, leaves, and branches and stems was significantly negatively correlated with concentrations of Na, Mg, K, and Ca in the soil solution. Among the three soils, the concentrations of these basic cations were lowest in the soil solution of the Cambisol. The fruit Cs concentration in the Cambisol did not change significantly with any soil treatments. In contrast, in the Andosol and Fluvisol, the fruit Cs concentration was significantly decreased by both acidification and fertilization. The whole-bush Cs content did not differ significantly among the soil treatments, whereas the percentages of Cs in fruit and roots depended greatly on the soil treatment within each soil, although the distribution trends relative to the control were opposite for fruit and roots. Our results suggested that the soil treatments to increase the concentrations of soil basic cations could reduce the rate of transfer of Cs to fruit and thereby contribute to a reduction in the Cs concentration in fruit, but not the whole-bush Cs content.

著者

Kaori Matsuoka Naoki Moritsuka Shinnosuke Kusaba Kiyoshi Hiraoka

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-100, (Released:2017-09-14)

被引用文献数

5

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In blueberry culture, sulfur is applied to enhance soil acidification, and fertilizer is applied to increase growth and yield. We investigated the effects of soil management on the solubilization of 13 elements in the root zone and their relationships with absorption by blueberry bushes. In a 2-year pot experiment, four-year-old rabbiteye blueberries ‘Onslow’ were grown in one of three soils (an Andosol, a Cambisol, or a Fluvisol), with or without soil treatment (no treatment, acidification, fertilization, or acidification plus fertilization). The soil solution was collected eight times during the experiment. Fruit, leaves, branches, stems, and roots were sampled during and at the end of the experiment. The concentrations of 13 elements (N, Na, Mg, Al, P, K, Ca, Mn, Fe, Cu, Zn, Rb, and Cs) in the samples were analyzed. Soil solution pH was also measured. In all soils, the soil solution pH was decreased to 3.7–4.3 by acidification and also to 4.5–6.1 by fertilization. Acidification tended to increase the average concentrations of Al (77–1421 fold), Zn (18–414 fold), and Fe (1.2–204 fold) in the soil solution, whereas fertilization tended to increase the average concentrations of NH4+ (33–205 fold), Cs (3.0–9.9 fold), and NO3− (2.1–8.4 fold). The acidification plus fertilization further increased the concentrations of these elements in the soil solution except for Fe. On the other hand, the concentrations of Na, P, Fe, and Cu in the soil solution were influenced by the soil type and were not changed by any soil treatments in a particular soil. Across all soil types and treatments, the average concentrations of N, P, K, Mn, Cu, and Zn in the soil solution were significantly correlated with the content of the corresponding element in the blueberry bushes. For these elements, nondestructive sampling and analyses of soil solution in the root zone can be effective as a real-time soil test. The content of seven other elements (Na, Mg, Al, Ca, Fe, Rb, and Cs) in the bushes did not reflect the soil solution concentrations partly due to the lower requirement than their supply from the soil.