ῒ ΐ ῏
J. Jpn. Soc. Soil Phys.

No. +*2, p. +*1ῌ+*2 ῍,**2῎

»  ¼ ½*&:;<=! - >?4'( + >)* @+,-

AB-CDEF+GFH.+/IJ0(KL())

MN1%4MG8J 2O3G*4P0M , >&C 7QR,ST+H.5J6U./780 +* 

9RV,38,:W%4G8XF0 ;<=&>,?34    !,@G/  !M Y4Z.R(/[-./AJ B6RVC\E%4] RVD0 + ;]E+*E,^4[8FG0^8 CH%#_-G0 I`J8  !M ?JaJ +bR(, KR6c (0^8LIM Mcd!e09&,34MG8C

NOP&f%GQR0gY06/ STῌ+ U]0C-R-R;!JVh-G 5FGYb

WX]&64G/YM ijRVMY0kIZ[l\C*B-mLD./J nR%G^./*+J]^0\-GoA _`JIG( p4

5B- + <=qr;, pa E-mail Jb,Mc Jd&eb%4G/ *;M - f,jY/YG#BD ghstiRVuvjkw D./ gh

C [M . fD./oA0^8  !&l3-JV

sti,X6b kxm  nm omP,M C6p5,q6/ ry%/sztM {tRV |,}-[ *w JbG#~*+,-.4G8 2 GBF ,R^8u0)\  !,5F0^8 vk D+F*+C^( w, \ox#B0y./

4%_./ _, \o4 %_./ 0^8
|}ῌxῌ~C+R(pa(yzῌ{ &>Y/(D+M E%3cJ %4G/ sztM _ Y&R|( qr;,.4 &*FR $%/

4

  &%4/(C%/ AFV

%4[6/ %R% AFY&R|8RAF{&064GR*|b B,M-8 +jkPC 566,-./XF

tZ8R5C5CY,Z8, Y&R|0^8 \|%/GJ-G*+C-GJ A

8J^8RB0M<d<JF,Ck _,M%4G-GCbR(D T

\^J(/ 0M*<d<$%  &'(    !&!)*+&(5FC-G0 szt,RG&,-./0 12"&#34 56,$789&%

L8*+,%/ +GFRL8X(-R./

Z8*+,%/ ^VRL3n&T%4[0M[l &¡Y/ _-M¢_.45B-70=_(M X +* ,,'.

G8  !C   !\£¤/Z,8 / X ,-./¡k¥¢nW-ARV £¢_8 %R% *+*RV ¦J^.4 k¤¥0C^8¦++-8+ AF¢3/VGGRY7RV-G P "ῌ§"]§t+%4 @¦%/ ¨¨©&%4M ©_8bR(;]Jª/

«ªCn4zk«RVY «,¬7( ­¬%G­ ¡ RV ®R-  ¯°±C®./ ¦P¯°²±& \³ª Y²³´´ µ&%/Y¶µ· ,)G4<=&Z8*+,-(D./  !&C)*+,-.

/D
\+[l&¸-<=,%4\/0   !&!./*+-R./LI,+.4  !&!)*+M k¹kRV 0C^./ ^ZM   !&!)r¶I·¥Jº_%R.
/ R¸4RV J[%/ST+   !M* ῌ

ῐῑῌ+ +* 



! "#  1,+ῌ2/+.  0ῌ+,ῌ+   +*2 6 ,**2

108

῎῏ῌ,







, 

῎῏ῌ-



789:;< = >?$@5  A:BC
8I$%&J'K(@52" L) ,**1 *  , 

D EF8G<!'2 $"4"H'"< #M(+,/N1-ῌ.AGO/!1J';0" 01,-2(345 P67Q@ 89  RSN1 TU):!1; V"< # ;(N5

<>N521/21=>(RW?@5 (@?/$"2 X Y@5ABZ C[ \] D21

? W^ E4F!5_#@(;`"abG@5

# J' H2; c4521/d*&/N1 eI

2"#$ fJ@521 @U@ 89 <g!

&lDmd<'UN1  h, KL@1i ABZ(jMk@1oQ< RS<pH  ;0N1 RS #!

N< O;*Pn

1 U  T (! SdU Vq;21 WXῌ

*Yr52'UN1 YZ'RS H$ [& \Z, ]I^ _<p$UI!1( W^ `q/stuqab(UU"H  H#f*v@ Sc(w<I!g*'2 Z *d?x$` / cmye!1) Tf/ [& \Zuqz{|1;(gh22H m6}n@ No oQ pq;/@dc4<q&` <@?52'2 $5*W^<F!g- ij<ekXNl >N521/21=>5~uN1( m6 rn rV<s9'8E-

'2 <f/ gt;< (uv@w4521

52" <xf{)U@2 WXῌ-* +* T<#$;0" Nony,-z

# U@2< xNd&ῌNn&$ c< / 6 {|o(}@521 {| ~(N104521/`12* /( g45*2)!

" o e6(No {|'2 + 7'#M $ f *N52" <xrq;oN1 6k $  U / 6 . 6

uw 45 (x#$25"H Z'?! 22'~Mz{'2 D# ;;!521 /( Z#<#

6*#. 6

 @, (eSN521 +`"U<L/( [& uq - 21/`') ? ?' $   !"#$ %&'() #!*+,U : $oN1$#/ n'- ./ 01&12$3452" & e6< s: /N1$ @5ji #  ¡( $ !  u2" $<24 . 6 / 6$* < g!¢!(g!

|521/`12$3452" ; ¡ £¤¥:¢!'& 89(\¦C}@ \§¨{",-¢< d! !*U£)U'© ª2¤@

SN52"$¥X¦'()*§¦@521 /«"¨;0"g i \§¨V",- @52"*&'() \ῌ ῑ ῐ ῍§8© ¦¬#$'d#<e! No*ª« \¦ $2¦a 21/21 g@5 \§ AB$V",-L) ¬ ,**1 : J' ­®]

2 3­21 @U@ 2¯# ABZ(+4,-%&J'$®¯ =°°n5"$ {U)'2#$/)?/ i ²§ῌR§J'³z,-W ±²³´³\§& µ & 1r ¶($,-789:

·/N189)'2  (  21 ´+,-51«/ g!

N¦µeo;]¶ ·55T ¸ ·552
'UN189(  \§ ¦¸ῌ©¹;`"#!lA:BC8I$

Y  pp. +ῌ,,, ±\ : ,**2  ,  2  : ,**2  ,  +. 