Runoff Loadings and Chemical Forms of Soil Phosphorus from Rivers in Japan during the High Flow Stages

JARQ : Japan Agricultural Research Quarterly
ISSN 00213551
書誌レコードID(総合目録DB) AA0068709X

The processes of soil phosphorus runoff into Hiroshima Bay via the Ohta River and composition of phosphorus forms in suspended matter in several major rivers in Japan during the high flow stages were investigated. In the Ohta River, the majority of soil runoff occurred as a result of terrestrial soil erosion due to heavy rainfall over several days of a year. In major rivers in Japan, phosphorus content in suspended matter ranged from 20 μmol/g (Yoshino River) to 71 μmol/g (Tone River) in which inorganic phosphorus accounted for over 50%. Potentially reactive inorganic phosphorus (CDB-P) accounted for 25 to 56% of the total phosphorus contained in sus pended matter during the high flow stages, suggesting that the CDB-P load from rivers equals of exceeds that of organic phosphorus. The higher ratios of CDB-P in large rivers such as Shinano Rivers such as Shinano River and Tone River may be caused by the erosion of phosphorusrich soil from large agricultural fields in drainage basin areas. In Hiroshima Bay, particulate phosphorus and CDB-P loads under flush conditions were estimated to be 2,600 t/yr and 880 t/yr, respectively. CDB-P load from soil substances discharged during the high flow stages was considered to be the main source of phosphate eluted from coastal marine sediments.

作成者 Katsuhisa TANAKA
国立情報学研究所メタデータ主題語彙集(資源タイプ) Journal Article
開始ページ 223
終了ページ 229
言語 eng