著者
佐久間 敏雄
出版者
日本土壌肥料學會
巻号頁・発行日
vol.50, no.1, pp.17-24, 1979 (Released:2011-12-08)
著者
柴田 英昭 田中 夕美子 佐久間 敏雄
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.65, no.4, pp.406-412, 1994-08-05

雪面に対する乾性降下物の沈着速度および積雪内部における物質の再分配を明らかにするために,1991年12月〜1992年4月に苫小牧市高丘に立地する森林地帯の開放露場において降雪および積雪の量と化学性を観測した.H^+ を除く,ほとんどのイオンにおいて降雪の平均イオン濃度は降雨のそれよりも高い値を示し,降雪による月間イオン負荷量は降雨に匹敵する大きな値を示した.乾性降下物の沈着フラックスを積雪中に存在する物質量と降雪によって供給される積算湿性降下物量の増加速度の差から見積もった.得られた沈着フラックス(μmol_c m^<-2> d^<-1>)は Cl^<-1>>Na^+>NH_4^+ の順に大きかった.SO_4^<2-> の乾性沈着フラックスは 27 μmol_c m^<-2> d^<-1> と見積もられ,海水起源以外の汚染源から主として供給されたものと推定された.また,雪面からわずかに雪が溶けることによって積雪中の物質が積雪内部を移動したことが推定され,これらの物質はざらめ雪上部で高濃度で集積する傾向にあった.また,その移動フラックスは乾性沈着フラックスの大きいイオンほど大きかった.イオンの移動速度係数(cm d^<-1>)は K^+,NH_4^+ が高い値を示した.
著者
佐久間 敏雄
出版者
日本ペドロジー学会
雑誌
ペドロジスト (ISSN:00314064)
巻号頁・発行日
vol.15, no.2, pp.70-86, 1971-12-30

The residual weathering crust derived from a fine textured sedimentary rock of Koetoi formation, which is one of the main parent material of podzolic soils and acid brown forest soil in the hilly area of northern Hokkaido, shows very high hydraulic conductivity (K=5×10^<-3>〜2×10^<-2>cm/sec). Vertical distribution patterns of hydraulic conductivity (=K-curve) of acid brown forest soil and related subtypes derived from this parent material have shown somewhat straight feature and hydraulic conductivity of the B-C horizon is in the range from 10^<-4> to 10^<-3>cm/sec. Genesis, morphological, physical and chemical properties of podzolic soils are closely related with their hydrological regime which is mainly controlled with the micro relief and hydraulic conpuctivity of the illuvial horizons, changes in the properties of podzolic soils with increasing humidity are illustrated by the following series of horizon sequences. Humus podzolic (Normal): A_1-A_2-B_<ti>-C Humus podzolic surface gleyed: A_1-A_<2g>-B_<ti>-C Podzolic pseudogley: A_1-A_<2(g)>-B_<tg> C_g or CG The K-curves of humus podzolic soils formed under the leaching-out water regime have the minimum value of about 10^<-5>cm/sec at the well developed illuvial horizon. During the humid season, upper soddy or illuvial horizons of humus podzolic surface gleyed subtypes are almost saturated with the stagnant water, which stagnate on the lower impermeable illuvial horizons (K=10^<-6>〜10^<-5>cm/sec). However, B-C or C horizons of this subtype of podzolic soils have moderately high hydraulic conductivity in the range from 5×10^<-4> to 5×10^<-3>cm/sec. The k-curves of podzolic pseudogley show the rapid decrease of hyaraulic conductivity down to the profile and conductivity of the Cg horizon of them is so slow (K≦10^<-5>cm/sec), that the B_<tg> horizon is left in the periodical stagnant water regime. According to the component analysis, variations of properties of these soils are closely linked to (1) the humus accumulation and related changes of physical and chemical properties, (2) formation of impermeable illuvial horizons and (3) changes of the soil water regime induced by the formation of impermeable layer in the profiles. From the results described above, it may be concluded that changes of physical properties, such as the reduction of coarse pore fraction and increase of bulk density, in the B horizons followed with the reduction of permeability lead the succession of heavy podzolic soils by controlling the water regime of them.