
J. Jpn. Soc. Soil Phys.
E
No. 22, p. -3 ,**+*ῌῌῌ
*ῌ***ῌ

Permeability and Water Retentivity of Peat Soil
Soil Physical Properties of Bibai Peat Land (ῌ) Hiromi IMOTO*,Tsuyoshi MIYAZAKI*, Hirotaka SAITO* and Masashi NAKANO*** The University of Tokyo** Faculty of Agriculture, Kobe UniversityAbstract
We measured saturated hydraulic conductivities, unsaturated hydraulic conductivities andwater retentivities of Bibai peat soils, consisted of highmoor peat (natural moss), transitional peatand lowmoor peat.
The transitional moor soils exhibited remarkable anisotropy of permeability. The verticalsaturated hydraulic conductivity was utmost about .** times more than its horizontal saturated
hydraulic conductivity probably due to the horizontal sedimentation of plant ﬁber.

Thisanisotropy was most remarkable in the subsoil of a paddy ﬁeld under the dressed soil and was lessin the undisturbed soils under windbreak.

Soil dressings and continuous cultivations may havea#ected the appearance of the intensive anisotropy.
The unsaturated hydraulic conductivities of transitional peat and highmoor peat were quite
small and were less than those of sand.

This feature caused the necessity of relatively long time

for the equilibration of water retention.
Key words : peat, wet land, saturated hydraulic conductivity, unsaturated hydraulic conductivity, water retention carve+    Fmno.p8+59DqG\"HR, ῍ !"#$ %

rstu/vfe+wxyz{|9}~/&$'(')*+, -. /01234

E῍Do=+, <R5/v=

῍ !" 5'.-.678+9:;- /34K JT   ῌ {|  !

'+, 5'<=>?@ABCDEABFG*"e.'+01῍>o=+, AB H IJ9)KLMNH">OPu/v/p.\R-'"QR D. H. Boelter +30/ ST +3// UV +33/F^_`a\" IJῌJ8῍ 0W῏. +33/ XT. +330 Y. +333 D 5'.A1῍Fo.p8+59F29\R,B Z[\>S]῍901῍F^_`a8+bcFde"f.[ ghij/fe+kl2**  ¡¢AB¢ £++-῍20/1 ¤v¥ +῍+῍+** ¦§¨©§ª«¬­®AB¯ £+*/῍***. °v±²³ +῍0῍/ ´µ¶¨ .F:  {| ·῎IJ¸¹ ·῎IJ¸¹ Jº»¼ + E 22 ¼ ,**+4,  

F!de0W33 kl6

 8 ?@mnF!Vo04%,**+ 3 p + +q60rs3.
F!F!Votu+53#  B5F!Vovwxyz{|}~+F!czi-

/f2 cm Yghij} }0 F!vwxyz{|}     !"#$%&'  ( )* 0+3 Z~+ F!0u3. Zk F!Vo+,-#wxij} OHP

+,-.} 0 F!}+F!%ῌ

/0123. 4. )*+567 x y} 0ῌ3 F!03.

8+92# :;0 +**< 3. 8=> 8=>

8 ?@ AB1". 8 ._ %d3#-. +  : + CD EF! G"H 8#H I$JK+/3.x y}  67k+:66 
~'0F!~'+,-#". C

L%&'#2 {¡¢}xῌ £6¤e+ 0 893῎83.

+333 0L%3. F!~'  F!B':+ F!0 &'D M&H0G"H 3.

+6._ zi} }0F!'+¥- ¦NO()H08#H + *PH08#H , KE§F!Vo0;- }3. F!:'3# - H01". 8#H0 , H+ Q.

<¨5+~B , cm ©ª0«Q ¬}wx­i+,  -R./+92#S0+&1T0 , ®¯° ±=>²o+?3 j³

U0VQ.C WX ' EY+ Z[K01". 4. F!:'+´µ}{0>­O«Q \23#2D]KD0^D_._-. , :  8=> +`a +33/ +bc.  ῌ+Fig. +@¶A?&. ·8 ¸¹iº12 B8C»D῍3.
-. -

: p , +q6mn8=>

Equipment unsaturated hydraulic conductivity mesurement.

MN :  >zNOPO>z15>?@ r sn 3 MTG[&BQTG[ST#op%$ Dtuv SRL> N1 QTlB>?

@wW'O($qx#y)z*DL Z
Z#3 >&B+>{,WRL#|k>-+3.|W }KW~1lB+>{,WXY
DL#|3k/>zW($qDL#yBw$  %OL/>zDL[#&KL G3S03tq 1T3u<%tM[X$1L }G 1T>?@3 +*\+ 5+*\, cms\+ ]^#2.|q 13>WDLZ#3t#KL>?@z13 QN1.|q )>SkG3>&B1l
B>?@W($qxqt`1 z1D)?@ >&B>?@ῌlB>?@ .!34 .** GR` 5QG[Q3ZKo.|tz1D!
ῌ,Fig. ,36&K< QG3>#Q7º»K¼L

8zCDZ#%& Q

Equipment for suction method mesurement.

z3 t90O`1.$#&KL Dtuv :G3;OL>?

@z3 +* <78KLW =f>

 NO. G. /   +, cm  +- cm  ,yZ#GzW@ +* <5+** <.$#&  +, cm  + cm >?@cm !"#$

%&'()'*+,-.%/012$34KL $%$ 1>W90W q
K?@3A&%G3t
tN >&B/ cm52 cm  -5/ cm 678-

99: ;0<2$q z3C)&Kt%` lB#>&B. .. + zW¤CK= . 3¥¦1T *5,* cm >?@CD !3.|q z3o#§¨&Kt%`=->?@MOL¡WXYDLG3t%#B¢$W £2N13¡Wt>?@ABCD = - .. , a 5 f 3 E=FGC$H.

>?@3 ©DW5ªV «A5F I$ J>  #$1

¬E8F­#®¯WRL#B¢KLG = / K1LM a 5 c NOPQ d 5#©DGf ¯?C$ M ªV «¬E8.

>?@GRL>#3 ,*5.* cm ST#UVTWX
Y$ ZK&>?@3M Q#[ +*\,5+*\- cm s\+ ]^G_ !GOL>?@#«¬E8>?@WDLB3¨&KLW 2

!°&|W.| QªV «¬E8
±H`1>?@W O`1²³DLR` S3a"bcde#$ff$ghªV#´IDLªV#W¨&KLW ZOytgi jb& +33/ GRLµWt¶KL%3JAGRLSkTlB>?@ mn 3MTG3ST#op%$q QTG3S
TO +5, ]^ 4 SkT>

.. -

= 0 >)z·¸3 M Q M
}K¹K1 AGC$; :  226ῌῌ-ῌKLMN

,**+}~

Fig. - Saturated hydraulic conductivities of lowmoor peat and transition peat area.

 0 a cm

C  /./0./  1,1../ cm  !"#$  %&  '()*+ , - ./0 '(1234567  8&   9:+; <=2345>?7
@A 3 BC5DE#

FGHIEJ$ 0 b KLMN O D -3ῌ/0 cm

PQῌRSTUVV  2/ῌ+*/ cm RSTUVVῌPQ

WJ$ @A 3XC$

 0 c XMN YZ G [\]3

5X7 ^\]35_`#$ [abcῌῌ.

XMN YZ}~

Fig. . Saturated hydraulic conductivities highmoor peat (wet land).

CJdefU g: h145ibC#jXk
lm!" n ^  ojcpC-FqHrstJuF2vw '()*: xyz5akl5^"#

FGHIEJ$ 3{"c |KLuv : j p`wx p$

ῌῌ/Fig. /

hijDklmnf

Saturated hydraulic conductivity and dry density of low moor and transitional moor.

ῌῌ0Fig. 07]opqr stWater charactaristics curve (hanging water column method, (a) lowmoor peat, (b) transitionpeat, (c) high-moor peat).

 F,  !""#$%&'()*+,HIJKLMNO

P.,Q 1 RSTF" Q 1 E

U16789:;<=>?@VPWXPEY+-&'./0"1+!2, 3 4, G()G,56789:;<=>?@&'A BCDEF"[\E 6789:;<=>?@A GCDE% 6789:;<=>?@e+/* cmH, o IfgE

Z1 ]0^_`aLMNO()bc!d3

@ ZE1 [ 22 ¼ -,**+18

ῌ1Fig. 1

¹69º8!"

ῌ2Yc»

Fig. 2

Ratio of soil samples height on suction
mesurement.

E(¹69º8WE

Unsaturated hydraulic conductivity.

,LsL(lh Ab_GFl+*ῌ   ,1 

/!"#$%&'()*+,
- .(/012 34567

89:;<+/* cmH, O ,

0*2*+/ 2 = >?@  +* ,*A'B(2CD( E FGH(AB

n31 -3r

Eῌq93r E1 kHQ  Ls,Ls(:BFlh b_:Bln312T ;t_  u< E n3
1 =v -!"#1 Mh:B%  8o67wxA:BH(A.%
-1 >1  ,LssL y(l.. .  2 IJ K %&  -(L -!"# -F1E

$%!MNOP -G11-D11.1  A /+*ῌ z{/1  !HQ  . .|?2/

2&QE RS2TV@:l2 + W(XYZu^, 'U V W(XYZ[ -, mm )H\1 !

'} ;~ _( EAFGMN*]^ E +_THV3456789:; <0*cmH, O , E   -`a1 b_F,cL -da1 Ae+-H Hf+ _'U

IJ2AVh BCD @

W(XYZ[ -ga1 MhGF &*]^E-ia1K.

EMh_FGH(A.

FGH IHJIJ N

 3 L2HH%  <0* cmH, O jc 789:;

:DM NOP Q b %&kHQ +2/QHlH

RL2HH , (::DST/@ E .01m2 E2 0E n31!MN
4567(8o67 WE2Cp
+1 q93r E :B  s

IJ ¡¢IJῌ£¤¥ ¦§l¥¨2UH K© ª« :¬« c« ­Vv®2¯FQ°QHH (::DSTIJ¡¢IJ

S±« WX²HQL2HH +& 3³F´µ¶·¸,²³ : '>%~´µe%NWXYGHIuv$wef& '(x:nyp& 0/῎ ῍ ῏ ῌ ῌ - : -,0+---Zῌ  +333 :ῌ῍

!ῌ"#$%&'()*%& 2+ : ,-+--.
Boelter, D. H.(+30/) : HYDRAULIC CONDUCTIVITY
OF PEATS, SOIL. SCI. +** (.) : ,,1+,-+.

,-./ῌ012ῌ345 +333 : '6789:;<=>?@A=BC& '()*2ῌDEabcdῌ0J_`ῌz{|ῌ[\]^ +33/ :}JN~QijJJ@N j%& -'(x:nyp&00 / : .,2+.23Zm +33/ : 'Jn&  : 0/+02.

ῌῌῌ+330 :,rJJef¡¢& '()*%& 2+ : //+/3.
,-./ῌ01

9Fῌ345 ,**+ : /GHIJK'()*% ῌ& '(LMNOPQR
ST& UVSTNWXY& '()*%Z[\]^ῌ0J_`ῌabcd +33/ : /GHIefghijJk*& il'mnop& 0- - :+3+,.Z[\]^ῌ0J_`ῌabcdῌqrst +33. : /%& '()*%& 1/ : +++,+.
£ ¤ (+3//) : ¥¦JN~Q>?9§& '¨& - +*) : /+2Z34pῌ0ῌ2ῌ©ª«ῌDEF +330 : '(uv)*@A=& pp. 0/++-0& z¬­o .
®¯°± : ,*** ° +* ± +/ ®*°± : ,**+ ° - ± +1 