著者
結田 康一 駒村 美佐子 小山 雄生
出版者
一般社団法人日本土壌肥料学会
雑誌
日本土壌肥料學雜誌 (ISSN:00290610)
巻号頁・発行日
vol.61, no.2, pp.165-172, 1990-04-05
被引用文献数
2

チェルノブイリ原発事故によって我が国にもたらされたI-131のコムギ地上部および土壌汚染に対する降雨の影響について,圃場での測定結果より解析した.1)コムギ地上部のI-131汚染に最も関与するのは,降雨に取りこまれない大気中のI-131である.非降雨期にはコムギ地上部のI-131濃度は経日的に増加していったが,降雨があると減少傾向を示し,とくに日降雨量が10mm以上の場合は前日より7〜35%の減少率を示した.2)土壌のI-131汚染に最も関与するのは,コムギ地上部の汚染の場合と異なり降雨に取り込まれたI-131である.表土中I-131濃度は降雨があると増加(大気中I-131濃度が低下した5月下旬は除く)しており,その増加率は前日比で9〜90%であった.増加率の幅が大きいのは,降雨中I-131濃度×降雨量で決まるI-131降下量に大きな違いがあるためである.一方,非降雨期には大気中I-131濃度が高くても表土中I-131濃度は減少傾向を示した.3)5月8日から10日にかけての表土中I-131濃度の50%もの減少は,表土から大気中へのI-131の揮散が降雨後の快晴,高温という気象条件によって促進されたためと推測された.4)地方面に降下したI-131はかなりの降雨があっても下層へ浸透しにくく,降下が始まった5月3日より48日後の6月20日においても0〜1cmまでの表層に57%が残留し,残り43%も1〜7cmの層に留まっていたCs-137,Cs-134に比べると土壌吸着力が弱く浸透しやすかった.5)コムギ地上部沈着I-131の水洗浄による除去率も同レベルと推測された.6)降雨中のI-131の存在形態はIO_3が主体で,次いでI^-であり安定ヨウ素の存在形態とも近似していた.
著者
栗原 宏幸 渡辺 美生 早川 孝彦
出版者
一般社団法人日本土壌肥料学会
雑誌
日本土壌肥料學雜誌 (ISSN:00290610)
巻号頁・発行日
vol.76, no.1, pp.27-34, 2005-02-05
被引用文献数
15 6

The Japanese limit of cadmium (Cd) in brown rice is 1.0 mg kg^<-1>, and brown rice containing >0.4mg kg^<-1> has not been previously used for human consumption. The CODEX commission of FAO/WHO stipulates that the Cd content in cereal grains, such as rice and wheat, should be <0.4 and <0.2 mg kg^<-1>, respectively. Given this situation, the rehabilitation of polluted paddy fields is vital to Japanese agriculture. Phytoremediation is an emerging technology that employs plants to remove environmental pollutants such as heavy metals. Such efforts have proven cost-effective and are less disruptive to the environment compared to conventional soil clean-up methods. We could select kenaf (Hibiscus cannabinus) as a suitable plant for phytoremediation of cadmium-contaminated soils through pot-scale experiments. Then we conducted field trials using kenaf for 3 years (2001-2003) at a cadmium-contaminated paddy field in the southwest area of Japan. The kenaf showed large amounts of Cd-uptake each year. As fallen leaves contained large amounts of Cd, which was proven in the 2nd year trial, we managed to cultivate them in a proper space to avoid leaf fall in the 3rd year. Concerning with the production and Cd concentration, both of which are depending on width between plant rows and cultivation period, we proposed double cropping of kenaf in the southwest area of Japan for remediation of Cd. Our data clearly demonstrated that a significant level of Cd in the soil was taken up through the phytoremediation with kenaf.
著者
中村 隆一 日笠 裕治 村口 美紀
出版者
一般社団法人日本土壌肥料学会
雑誌
日本土壌肥料學雜誌 (ISSN:00290610)
巻号頁・発行日
vol.74, no.3, pp.317-322, 2003-06-05
被引用文献数
1

1.ブロッコリーの花蕾腐敗病は、窒素施肥量の増加に対応して多発した。発病株率の高い区では低い区に比べて花蕾部の窒素濃度が高かった。カルシウム資材を花蕾部に葉面散布すると、花蕾部のカルシウム濃度が高まり、花蕾腐敗病の発病株率は低下した。2.花蕾腐敗病の発病には花蕾部の窒素濃度の他にカルシウム濃度が影響する。花蕾部のCa/N比が低いほど発病株率は高く、Ca/N比が0.2以上では発病株率は10%以下で、Ca/N比が0.3以上では発病が認められなかった。3.窒素を分施することで、地上部カルシウムの花蕾部への分配比率が高まる傾向が認められた。したがって、花蕾腐敗病が多発する作型では窒素の分施が発病抑制に有効である。4.低地土が主体の地区で花蕾腐敗病発病状況を調査した結果、花蕾腐敗病は有効土層が浅く、下層土のち密度が高いなど排水性が不良な圃場で多発した。5.以上からブロッコリーの花蕾腐敗病の発病には、花蕾部の窒素濃度とカルシウム濃度が関与し、発病の抑制には窒素の分施および土壌物理性の改善、カルシウム資材の葉面散布が有効である。
著者
三枝 正彦 松山 信彦 阿部 篤郎
出版者
一般社団法人日本土壌肥料学会
雑誌
日本土壌肥料學雜誌 (ISSN:00290610)
巻号頁・発行日
vol.64, no.4, pp.423-430, 1993-08-05
被引用文献数
7

東北各県より代表的耕地黒ボク土393点を入手し,酸性シュウ酸塩可溶アルミニウムに対するピロリン酸可溶アルミニウムの比,酸性シュウ酸塩可溶ケイ酸含量および粘土含量を用いてアロフェン質黒ボク土と非アロフェン質黒ボク土に類型区分することを試みた.さらに,この結果と前報で報告した交換酸度y_1による開拓地土壌の類型区分結果をペドロジスト懇談会作製の土壌図に作図し,火山灰の分布状況,風化に関係する気候要因,火山灰の岩質,火山ガラスの性質を考慮して東北地方における両黒ボク土の分布と分布面積を検討した.アロフェン質黒ボク土は,全黒ボク土の48%,86万haを占め主として完新世テフラが厚く堆積する地域で,降水量が少ない青森県南東部から岩手県北部にかけて,母材が塩基性の岩質あるいは有色火山ガラスを主体とする岩手山,蔵王山周辺,軽石を含む火山灰降下地域と考えられる秋田県北東部,福島県北部に分布していた.これに対して,非アロフェン質黒ボク土は,全黒ボク土の52%,94万haで年降水量の多い日本海側の各地,高標高地あるいは宮城県の内陸部に,また降水量は相対的に少ないが完新世のテフラの降灰の少ない岩手県南部から宮城県北東部に主として分布していた.東北各県における非アロフェン質黒ボク土の分布割合は青森県30%,秋田県80%,岩手県43%,山形県100%,宮城県76%,福島県42%と推定された.
著者
中林 和重 山崎 邦典 斎藤 伸芳 飯泉 正 島根 茂雄
出版者
一般社団法人日本土壌肥料学会
雑誌
日本土壌肥料學雜誌 (ISSN:00290610)
巻号頁・発行日
vol.61, no.5, pp.479-484, 1990-10-05
被引用文献数
5

メロンのロックウール栽培における培養液の組成と培養液の供給方法について検討し,以下の結果を得た.1)ネット出現後期から窒素の供給を制限した方がよい:ネット発生期以降の培養液中の窒素濃度を,1/2にした場合には,ネットの太さにばらつきがなく外観が美しかった.この制限を始める時期はネット発生期よりも遅い時期がよいと思われた.2)収穫直前の給液制限はしない方がよい:収穫の20日前から給液を制限した場合には,果肉の糖度も低くなり,果実も小さくなる傾向があった.このことから,メロンのロックウール栽培では,培養液の供給量を栽培の全期間にわたって,制限しない方がよいと考えられた.3)培養液への腐植酸の添加は有用:培養液に腐植酸の添加(50 ppm)を行った場合には,果皮色が明るくなった.今後,さらに検討を要する.
著者
Ando Ho Kakuda Ken-ichi Nakayama Munetaka YOKOTO Kei-ichi
出版者
一般社団法人日本土壌肥料学会
雑誌
Soil science and plant nutrition (ISSN:00380768)
巻号頁・発行日
vol.46, no.1, pp.105-115, 2000-03-01
被引用文献数
2

Due to high the labor cost, direct seeding is being gradually applied for crop establishment throughout Asia. Recently, the development of the so-called, "controlled release fertilizers" (CRFs) which requires only "one shot dose" of N, has enabled to reduce the cost of labor for the application of topdressed N. Thus, in order to limit pollution and cost, no-tillage direct-seeded lowland rice cultivation accompanied by the use of CRF is being recommended. To evaluate the effects of CRFs on the growth and yield of no-tillage direct-seeded rice, a field experiment was carried out in the north-eastern region of Japan in 1993 and 1994. Five N treatments were used: (1) ammonium sulfate (AS) band placement application with seeds at the time of seeding (AS1); (2) AS broadcast application after irrigation (AS2); (3) CRF (LP100) co-situs application at the time of seeding (L1); (4) CRF (LPS100) co-situs application at the time of seeding (L2); and (5) minus N (MN). The rate of basal N was 60 kg N ha^<-1>. Topdressed N in the AS1 and AS2 treatments was applied at 25 d before heading at the rate of 20 kg N ha^<-1>. The highest yield was obtained in the L1 treatment in both years. The number of grains per unit area was affected by the amount of N in the plants at heading. The percentage of filled grains in the L2 treatment was the lowest by about 15 to 20% among the treatments. The recovery percentages of basal N on July 20 were about 20 to 30% in the AS1, AS2, and L1 treatments, and only about 14% in the L2 treatment. About 75 to 80% of basal N was absorbed by the plants at harvest in the L1 and L2 treatments. On the other hand, the plants had absorbed only about 25 to 30% of the applied basal N in the AS1 and AS2 treatments at harvest. There was no difference in the N-recovery percentage (based on the amount of released N) between the L1 and L2 treatments. Nitrogen-use efficiency was not significantly different among the treatments. However, higher N-use efficiency was obtained in this experiment than in early studies in the tropics. The agronomic efficiency of CRFs was higher than that of ammonium sulfate.
著者
Priyadi Kahar Hadi Abdul Siagian Tiusbul H. Nisa Chatimatun Azizah Aulia Raihani Nilly Inubushi Kazuyuki
出版者
一般社団法人日本土壌肥料学会
雑誌
Soil Science and Plant Nutrition (ISSN:00380768)
巻号頁・発行日
vol.51, no.5, pp.689-691, 2005-09
被引用文献数
1

A field experiment was carried out to elucidate the effect of chicken manure (CM) and effective microorganisms (EM) on the yield of corn and chemical and microbial properties of acidic wetland soils. A split-split plot experimental design with three replications was used in this research. The main plot consisted of two types of soil. The sub-plot was for the application of CM, while the sub-sub plot was for the application of EM. Sweet corn seeds were planted and cultivated until harvest. Above ground plant biomass and round of the stem of an ear of corn were observed. Soil samples were taken and analyzed for chemical and microbial properties. The results showed that the interaction between soil types and CM application affected the corn yield, while EM had no effect. Similarly, the chemical and microbial characteristics of soils used were affected by soil type and the application of CM, while the effect of EM was not clear.
著者
佐々木 清一 石塚 喜明
出版者
一般社団法人日本土壌肥料学会
雑誌
日本土壌肥料學雜誌 (ISSN:00290610)
巻号頁・発行日
vol.25, no.3, pp.129-136, 1954-10-05

Twelve soil samples were collected from Southwestern Hokkaido (including the Oshima peninsula); five samples were used for the present investigation, viz., Yu-no-tai, Imagane, Kuromatsunai, Ginzan and Maruyama soils. (Fig. 1) The size distribution, the amounts and properties of soil humus and the amounts of colloidal matter after TAMM'S method were determind respectively, as well as the inorganic components, acidities and base-exchange capacities. According to the data thus obtained, the authors concluded that the soils of Yu-no-tai, Kuromatsunai and Maruyama belong to Brown-forest soil. Imagane and Ginzan soils apparently are podzolic in their characters. But judging from the ultimate pH value of these last two soils it will be reasonable to understand that these two soils are in the process of regeneration from Podzolic soil to Brown-forest type. The authors published a soil map of Hokkaido based upon studies, made up the present. (Fig. 4 of this report Part 5).
著者
建部 雅子 石原 俊幸 松野 宏治 藤本 順子 米山 忠克
出版者
一般社団法人日本土壌肥料学会
雑誌
日本土壌肥料學雜誌 (ISSN:00290610)
巻号頁・発行日
vol.66, no.3, pp.238-246, 1995-06-05
被引用文献数
33

Spinach and komatsuna were cultivated with 0,10,15 and 30g N m^<-2> applications in an Ando soil, and the changes of the contents of sugars, ascorbic acid, nitrate and oxalic acid which are the constituents related with the quality of the vegetables, and the relations between the growth (fresh weight), nitrogen status and the contents of these constituents were investigated. Ascorbic acid is contained both in spinach and komatsuna, but oxalic acid is contained at a high level in spinach and at trace levels in komatsuna. Nitrate nitrogen contents increased along with the increase of applied nitrogen, and reached 1.14g (kg FW)^<-1> in spinach leaf petiole and 1.26g (kg FW)^<-1> in komatsuna leaf petiole at harvest with the application of 30g N m^<-2>. In both crops, sucrose content was highest in the plot of 0g N m^<-2>, glucose content was highest in the plot of 10g N m^<-2>, and they were lowered with increased application of nitrogen. Total ascorbic acid (ASA+DHA) content was decreased by increasing the nitrogen application : from 0.74g (kg FW)^<-1> at the plot of 0g N m^<-2> to 0.51g (kg FW)^<-1> at the plot of 30g N m^<-2> in spinach and from 1.00g (kg FW)^<-1> at the plot of 0g N m^<-2> to 0.48g (kg FW)^<-1> at the plot of 30g N m^<-2> in komatsuna. In spinach, the total (water-soluble plus-insoluble) oxalic acid content was increased in the leaf blades and decreased in the leaf petioles along with the increase of nitrogen application, and there was no difference in the whole leaves with the treatments. The contents of sucrose and ascorbic acid were high in the plants in which yield and nitrogen content were low and dry matter content was high. In view of the quality of spinach and komatsuna, the low nitrogen application is better, but the amount of nitrogen application must be determined considering the maintenance of growth and yield.
著者
竹内 誠
出版者
一般社団法人日本土壌肥料学会
雑誌
日本土壌肥料學雜誌 (ISSN:00290610)
巻号頁・発行日
vol.68, no.6, pp.708-715, 1997-12-05
被引用文献数
26