5 N 3+ ;" +.  1 +/  -  ./ 1 -+ N

 3+ 

ISSN *-21w0*+,῍ῌῌ῍ ῎     + 
Soil Erosion under Co#ee Trees with Di#erent Weed Managements in Humid Tropical
Hilly Area of Lampung, South Sumatra, Indonesia
AFANDI, T.K. MANIK, B. ROSADI, M. UTOMO, M. SENGE, T. ADACHI and Y. OKI -ῌ 

!ῌ ῌ"#$+/

Sediment Yield from Various Land Use Practices in a Hilly Tropical Area of Lampung
Region, South Sumatra, Indonesia
AFANDI, B. ROSADI, MARYANTO, NURARIFANI, M. UTOMO, M. SENGE and T. ADACHI,/%&'()*+,-./01234 56789 :;ῌ<= >?ῌ@A BCῌDA EF-3

GH 5 IJKLMNO4PQ R7ST

!ῌ ῌ"#

$.3

 
UVWX YZ,[\]^_`abcdῌefgῌhijkῌlmno^p
Ustu*vwxyz{|}~ MwpqX rF/3 0*0+0-῏ ῎ ῐ ῑ ῍ ῌ+῎ bcd , 7 Japanese Society of
Soil Physics 
3:Z>#83 B[\3C]<῏ e
 ,  
  "fg7
   
fg7h< b 9Xe"6aY;
 -   !" 1  6=, + iR>? #83jX#$ῌῌ ?kl8mn Go[\ "b  %&'()῍ * + Journal of the Japap @qῌmq ABrCm)
?
nese Society of Soil Physics,   3!3Gs]<῍ #83 33t B>&?/33
-. #῎ /  0 1
C ?8u W"vw
2
#83866a< o῏   
῎ ?#838mY0DLMEFm
&
"

UV ABr ?CGx- H , R>4 .  3 3 !345
3 6"3 . 73& 2  < #83?8y\6869XY36e"a<#839$:;&;<=&>&? % @ A& B';Cz# <z# &{IJ )&;<=&>&?
 3   !Y3ST
ῌ 3t|Y3 /  3!(D)E*FG +H3:Z>#83 B[\3C]< /,/** J#833t| 3,I-,*** J
῍ 9XY3!3,I
-K!LM3:Z>#83 B[\3C]< Y,,,/** J
3 B[\s]< *-.
453
NO,I
1,/** J
6"3
*,I
9X K
+/,*** JPQ.
453
+* y((}L~[\o\453R/ ,,,/** Jb,M=, .  + * F 0   !/3ST 0E , ,N, -  -+ * UV - E12W0$ &? 3C45
OA ῌ 1PQ<KH! RT
++-ῐ20/1 S TU V!+ῐ+ῐ+! Bῌ 6 + 7 86 + 7 9XY36 + 7
S --K !W 
3:Z>#83 B[\3C]<!ῌX YZ 
῍ # 8 3῍ A +333 , .  + *B#,**+++,*  ^ +/ 7
3:Z>_3
` -7R6a 3:Z>Y;
῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍῍ 
+ [x$&TH + \3G&;<=&>&? UV9XY3a]V^
G&?
, _9XY3am)  9XY3
 +U, SB + , ?\ , 7 + 7"x3G"] - `H B + +U, (Original papers) : abao SB
c
%&]< H N9 UV\sd\?\ * e H   fU
  ,/* words R U Abstract U  /** ¡RfU@; , + , Notes : 
gV?"¢£ 45h&'i?jQG
abao* e H fU +,/ words R U Abstract  U ,/* ¡RfU@; +?k, Reviews : 
 ¤l?\ <FG ?¥V ¦§ 4¨m H. +©k, Lectures : 
 1"v©b  nª&©k &>
 0« ¬­&'/ + ¬­, My research : ®¯#[\?
 *C °±]<U >o&' ?\nª&¬­0 +²., (Miscellaneous) : PT3³´&jQ£pj
1 +qµ, Readers’ column : +,¶r ?\st£·%&'2 +A#, Book reviews. `.>a 0 ¸¹RV <º ^  + ¸¹o 3,*** J[xuv  F »¼-.^¢([xuv -/   
Foreword  
Lecture series       
!"#$%&'()
0)* +  +  ,-. , '/ - 0 1 23 4
 5 6)*1  
3#"789: "!;<.=>" "* >" ?@A#B$3#"7 % "&"
)*
2 &"'(CD" )
 0 EFG*HIJK0LMN)
3 &"O+O'P)* >" ,
Q0RSTP'-I+* S0 -* &"./)* UJG0V1)* +23,3*++ W?@IJ"456'&XY789%Z[:)*
+333 ++ ,* \+ ]'' + A . ; ,/ < ,- $ 0L^_ -* mm G0'=>* . ?` + a.b* , ]' cD@A &"BK U'de]` @A &"B f=g.h  C:
ijCkD975KlD* >"
E + a.b'mF ]'C:ijCkD /nG*'o.p.q- 45rstuv.w e5 Abstract 'L/ nG*'e]' Key words 23*
. e]' A . ; xy=za.z`XG)*
H 0** words ` + a.b*/ e]'45rstuv.w Manuscript title,
Full names of authors, Address of institutions ofauthors, ,/* words G*'e5 Abstract rs /nG*'Key words 975KlD*0 e]]I{ / nG*']o.
p.q23*
1 e]'J|)}&"'KL$%~ MNZ45"0O"0"~'d*e]'gyz-..r# 
IJ*1>
2 O$PB$)*K p.
fwB "f=>"ozw
f='Q#"f-.zR)*3 5 S'N + , - T'N++ +, +- 'N +.++ ++, ++-
'r%)*+*  6'<U8 0K LK
5< >7!5< VW'"DX`(#)*
++ Y] Y:%K cDUJ"
KBZ& ) [ : \]^CEC +, _'` _¡ SI r*+- a @ bc': a + @ , bc - 'r% e]d¢)* + Fig. + Table ,Photo. - )* e]'` bc Fig. £%+. a @ bceIBfQg h¤@ai @ )*j3*
+/ a @ bc + ?k A . ;`XG)*9 >" A . ;'1l03* =>&"Ba@6':X`¢)+0 abcU'>>mnIJ*'` o&')*
+1 a +/, prU'qfr(# , p
7sK a't'uI85<'sKI
 S000'sKI¥vAD*
+2 Da8¦w§bc#x23 qx8pr
23
+3 ]'45 tuv.w' + a @ bc'
ABe]y¢)*,* a @ bc':AB 1>D¤z@)*,+ 5{`5¨©|)* + &"B }~ >" &"B }~ )* [ : Tanaka +33. Nakamura and Suzuki, +32+  &" - BG0'
+E + &"B'd῍῍7 >" et al. 
23* [ : ª7 +312  Tayler et al., +3./ ,, ©|5¨ 5'd&"B' ABC  @ «©|5¨¢@,- ©|5¨'K`GL'r%)*Bouma, J. and Dekker, L. W. (+312) : A case study
on inﬁltration into dry clay soil, I. Morphologicalobservations. Geoderma, ,* : ,1ῌ.*.
FAO (+322) : Revised legend of the FAOῌUNESCO
Soil Map of the World. p. ++3, FAO, Roma.
¬­ +31* : 789%aqb. aqbzw +. : ,2ῌ--.
ª® ¯( +303 : 789%p. //°±
²W'a.b p. 8 pp. 23 '_a.b ) +
a.b ) + p.,
 pp. 23*[  SI  ] _¡ SI 2'n9`IJ
*'`~~789%j'_'|[ )
IJ*_ D7J*_
kg kg´+*³
m- m´U³r
mL, cm-, mLU
kg m´-, Mg m´g
kg m´-, Mg m´- g L´+, mg L´+gmol m´mol L´+µ=gNkPa, m, cm, **¶·= J kg´+
m s´+
cm s´+¸]^ molc kg´+, cmolc kg´+
s´+
min´+

kg m´,
kg ha´+, Mg ha´+, t ha´+^* ῌ@  ;'*]hc&'' +¹3|*** cm H, O !
U' º'd*&'2»N
`¼ )*,*** - +* \῍ ῎ ῐ ῌ ῏












 

:      ῌ     



!" 

#$%
#$&
'()
* : / +,-'()&* : / +,-

./0 +
123
./0 ,
123
./0 12345

 

6ῌ7645

 

6ῌ7645

 

6ῌ76

89:;0
<

4

?

=>ῌFAX 
Eomail

#



J

FAX :

Eomail :@ABC



TEL :

K

A. : 

B ῌ .** 3D@AEF 

B

G

B

B
H I

B

-* L ῌ /* L ῌ +** L ῌ +/* L ῌ ,** L ῌ -** L: MA!N:OPQRSTUVWXYZ![\
http://soil. en. a. u-tokyo. ac. jp/jssp/




     ῌ  ῌ  ῌ" # $ % &
'

$

%

&

(

)*+,-./
0



1
$



$

%

3

4

5

) * 6 7 8

ῌ

2
%

9

)*:;ῌFAX <=ῌ
Eomail> ? @ 6)*:;ῌFAX <=ῌ
Eomail
 A

 B 5

345

ῌ

CDE FG
6H
C IB$%& :JK$%& :
L5ῌMNOPQRST &C4UVW, XYZ[ \
9++-ῌ20,, ]^_`^aCb# /ῌ+0ῌ3

UVW, C,+
Tel. : *-ῌ/2+.ῌ/2+*>?

!

  
J. Jpn. Soc. Soil Phys.
3
No. 3+, p. +, ,**,

   *           !" #$   +0 % 33 &'()*+",- .%  /
0123456789 :COE ; ;<= -*> ?-@7' #ABC' , 7%D.6EC' 23FG%H I!
JK01G"L #$. C # "%MN O&P(Q
6 $ O&P('R (S)6CTU%#O&P*+CE  V67 ,WXY-.C# 6  ZQ'[ῌ/CE \-+ 0]^,WXY, 01.' # V,W_ 
23I2 01I2 `3abc4def g+I2h56ECiU# ,WE^
,WETU6j",#7(17 V8(kl,W mn9opqr(:Vs;' .%kl,W",# V' Vkl,W<=Et(u> :?v@> ,W(w+# *xA C yz :B{> C#E V,W ZQ'XY.",|tE6j",# , } DE~F* :G>

g+HIJ). K%XY.6#

,LM"kN (XY;C t%MNMO",Q6#  ) 
> k%nῌn9() "U ῌ>k

>

P :

:Qx> R(S+CTC6# !JVkNTU6 C  C6 :, W

6> X(Y- >J$013Z  WP[-01()  23  '+%kl"q(\]+"  4d W^H

:> q_J W`q at23 :> ((bc  XY+0] :>> ( $ 0]XdC'e
U' 6CTU(UQ6# * C C;C#(Hf bdC'Rgh. i jklJu>ymn oc(p qC 0¡.#"E +332 r£sm23@(89+ TLO  :¤t¥uvw>¢Z- ¦x§J¨©ª«I89¬Q' #  klCy@(,WP­% xA z{' #x ®="®,WopqrR;",|t# |U­ ¯ }~:+[s;(1/*ῌj^*+.' #  C'&°.s;1/*ῌj^*+;",Q'E }~:+[s;tS ; g-yE"EN±U%
 ²:³B :.³B> (1/*+ C # U, 0]U  .³B>#( 7' C´" Ai  ®="®,WopqrRµCi(U #" C (i¶mE- * ·¸¹º3»> ¼1**ῌ2/-* H -ῌ+ῌ+ZtxAH R67

efghq  3+  ,**,

2 
  !" #$%&'()*+,-. 0 /0123

4567ῌ4589:;<=&>?@ABCDEF GHIJKLMNOP @" >Q RST(UTVWBXYZ[\]^"
O_`abc 'defgh6iLefghjklmn^opLY ef
ghqrs&tG uvYwQxyz!"{ |}~}ῌ}  (%|}Y(xyY &Xo^~Q YL.
x5^ !"ῐ
J. Jpn. Soc. Soil Phys.
ῐ῎῍ῑῒ῏
No. 3+, p. -ῌ+. ῍,**,῎Soil Erosion under Co#ee Trees with Di#erent Weed
Managements in Humid Tropical Hilly Area of
Lampung, South Sumatra, Indonesia
AFANDI*, Tumiar Katarina MANIK*, Bustomi ROSADI*,
Muhajir UTOMO*, Masateru SENGE**, Tadashi ADACHI***and Yoko OKI**** Faculty of Agriculture, University of Lampung, Jl. Sumantri Brojonegoro
No. +Bandar Lampung -/+./, Lampung Province, Indonesia** Faculty of Agriculture, Gifu University, +ῌ+ Yanagido Gifu /*+ῌ++3-, Japan*** Faculty of Environmental Science and Technology, Okayama University,-ῌ+ῌ+ Tsushimanaka Okayama 1**ῌ2/-*, Japan
Abstract
Soil loss and surface runo# from farmland under co#ee trees with di#erent weed managements
were investigated in Lampung, South Sumatra, Indonesia during rainy seasons from +330 to +333.
Three treatment practices investigated were as follows : co#ee without cover crop ; co#ee with
Paspalum conjugatum sp. as cover crop, and co#ee with natural weeds. Weed management wasdone every two week by clearing all the weeds in co#ee plot, and cutting the weeds around theco#ee trees with diameter + m for the weedy plots. The results showed that the maximum daily
rainfall and intensity based on +* minutes observation were 2, mm/day and +,* mm/h, however,
only +..,ῌ of rainfall intensities was greater than ,/ mm/h (classiﬁed as erosive rainfall intensity).
A relationship between erosivity index (R) and daily rainfall (X) was found as follows : Rῌ+.0,.
(Xῌ+*.3), where R : daily erosivity index (m, · t/ha/h) and X : daily rainfall (mm/day). The runo#
ratio for cleanoweeded co#ee ranged from 1.* to +/.3ῌ, and decreased after the second year
because of the co#ee canopy growth. The presence of Paspalum conjugatum had reduced runo#
until zero after the third year, whereas in natural weeds plot, runo# became zero after the fourthyear. The highest soil loss was found in cleanoweeded co#ee which reached ,,.1 t/ha in thesecond year of experiment. The use of cover crop could suppress soil loss until zero after the thirdyear in Paspalum plot and after the fourth year in natural weeds plot.

However the goodmanagement of weeds as cover crops is necessary due to the bad performance of co#ee growth atboth weedy plots. The average soil loss from cleanoweeded co#ee plot was +.,. mm per year
which was below the soil formation rate in Indonesia.
Key words : co#ee, soil erosion, runo#, erosivity index+.

Introduction

Lampung, located in the southern part of
Sumatra Island, is one of the biggest co#ee
producing districts in Indonesia. About /*ῌ ofco#ee production of Indonesia occurs in
Lampung. From +33* to +33., the average ex-port of co#ee bean from Lampung was +/3,31*
tons out of -,3,*1* tons of total Indonesian’s
co#ee export (BPD-AEKI, Lampung, +330). In+333, the co#ee export from Lampung
amounted to +1/,2** tons out of -/.,*** tons
(Bank Indonesia Bandar Lampung, ,***).
The major problem of the co#ee manage-

῏4

ment in Lampung is that the co#ee trees were
mostly planted in steep areas where the soil
conservation is usually not applied very well.
Clearing up all the ground cover under theco#ee plants is the most popular practice forweeding management. The farmers perform
such a management practice due to the factthat the co#ee root system is abundant aroundthe upper part of the soil surface, so even small
weeds like grass type will inﬂuence the co#ee
growth. This reﬂects on the nutrient component of the co#ee leaves due to competition
between co#ees and weeds if the weeds wereleft unclear. However, clearing all the weeds
promotes soil erosion since this area possesses
a humid tropical climate, characterized by abundant rainfall and high rainfall intensity concentrated on rainy season.
It is well known that cropping systems withground cover maintenance, especially in rainyseason, are recommended for farming on slopesin order to reduce soil erosion. Unfortunately,
the study of soil loss under co#ee plants in thetropics is limited, and a little information isavailable about soil erosion from co#ee areas
in Indonesia. An erosion study by Gintings(+32,) in Sumber Jaya areas, Lampung, measured soil loss in Robusta co#ee under natural
condition without any other management. The
co#ee tree used was +0ῌyr old for 2ῌmonths
measurement, and +ῌyr and -ῌyr old for 0ῌ
month measurement.
A 0ῌmonth erosion
study was also conducted in Bali by Pudjiharta
and Pramono (+322) in +/ῌyr old co#ee trees.
The information derived from the studies wasjust the amount of soil loss from co#ee plantation in a short period. Some researchers inIndonesia also have used some grasses as cover
crop, but it was limited for horticultural cropor annual crops, for example Abujamin et al.
(+32-) used Bahia and Bede grass, and Utomo(+323) reported the using of King grass in sandy
soil in Indonesia.
Lately, the problem of soil erosion in
Lampung, Indonesia, has accelerated the following political changes. Due to weak law

3+

,**,

enforcement during the reformation period in+332, the public was encouraged to open the
Calliandra reforestation areas. In a very shortperiod during +333, thousand of hectares ofprotected forest in Sumber Jaya were converted into co#ee plantation. The increasing of
co#ee bean price more than three times alsoenhanced the forest squattering in +332.
The current controversies on soil erosion in
the co#eeῌgrowing areas in Lampung persist
due to lack of comprehensive research. Since
most co#ee farmers in these areas apply clean
weeding management, a prompt evaluation ofsoil loss under existing methods of farming
and other alternatives of weed management
was in need. Thus, the objective of this four
years study was to measure the e#ects of
di#erent weed managements under Arabica
co#ee plants on the extent of surface runo#
and soil loss.
,.

Materials and Methods,. + Study site
This study was conducted during the rainyseasons from +33/ to +333. The study site was
located at Sumber Jaya District, Lampung
Province, South Sumatra, Indonesia. Geographically, it is located at +*/*+’ EL and *.-.’
SL. The slope gradient was around +/with theelevation of 12*m above the sea level. The
average rainfall recorded from +31. to +332 wasaround ,/** mm/year and the air temperature
was around ,, (Afandi et al., +333).
The soil had the initial properties as shownin Table +. The soil was dominated by clay
fraction in all depths, however the soil bulk
density was very low, which is indicating thatthe soil was friable and porous. The color ofsoil proﬁle (up to +** cm soil depth) was
dominated by brown to red color which indicated that the internal drainage was very
good. The soil reaction is slightly acid withmoderate cation exchange capacity. The soilorganic carbon was quite high probably due tothe fact that the decomposition rate of organic
matter was relatively slow. Based on the aboveῐ῏ : Soil Erosion under Co#ee Trees with Di#erent Weed Managements in Humid Tropical Hilly Area of Lampung, South Sumatra, Indonesia

Table +
Depth
(cm)

pH
H,O

*῍+*
+*῍,*
,*῍-/
-/῍0*
0*῍+**

.43,
.423
.43+
.421
.42/

5

Initial soil characteristics prior to planting

Total-N Organic-C
CEC
Texture (ῌ)(ῌ)(ῌ)(cmol/kg) Sand
Silt
Clay
*4,0
*4+0
*4*3
*4*1
*4*0

Fig. +

-4.2
+420
*423
*42,
*42,

+-4343
34241
241

,/
,/
,0
,0
,2

,+0
+++/

/,
/3
0+
0+
/1

Bulk density(g/cm-)*430*43*433*43ῌ

The design of experimental plot.

soil properties, the soil could be classiﬁed as
Latosol (Indonesian soil classiﬁcation system)
or Dystrudepts (Soil Survey Sta#, +332).
,. , Treatment plot
The erosion plots were consisted of threeplots with +/῎gradient, ,* m slope length and /m width, and bordered by -*ῌcm height zincmetal sheets. Two collection units were installed at the lower end of each plot. The ﬁrst
unit was a ditch with the capacity of *.+ m-,
which was connected to the second unit (a tank
and water reservoir) by seven pipes. One pipe,
which was in the center, was connected to atank by a siphon and the others overﬂowed
into the water reservoir box in which a triangle
weir and a water gauge were installed. The
detailed design of the plot was shown in Fig. +.
The treatments were as followed :(+) Treatment + (cleanoweeded plot) : Groundsurface was always keeping bare by hand
weeding at two weeks interval. This management is a general practice in this co#ee plantation area so that this treatment is regarded as acontrol.
(,) Treatment , (Paspalum plot) : Co#ee with
Paspalum conjugatum as cover crop. Young
Paspalum conjugatum was transplanted to theexperiment plot in November +33/ and February +330.
Paspalum conjugatum is one of weed species,
gramineous perennial of the South Africa
origin. Its stalks, hard and long, are crawled
over the ground, putting out an irregular roots
from joints. Its growth speed is very fast andthe rhizomes are dense. This plant was widelyused in both private and public park areas in6Indonesia.
Instead of these reason, we used Paspalum
because it was abundant in that area and very
easy to manage.
(-) Treatment - (natural weeds plot) : Co#ee
with natural weeds as cover crop.
In each plot, seedlings of Arabica co#ee wereplanted with planting distance +./ m by , m on
November +33/. Weed management was done
every two weeks by clearing all the weeds incleanoweeded plot, and cutting the weeds
around the co#ee tree with diameter + m forthe weedy plots. Before and after rainy season,
the Paspalum mats and natural weeds were
mowed at +/-cm height. Application of fertilizer and pesticides had been adopted according
to the standard usual practice.
,. - Rainfall erosivity
Rainfall was measured by automatic weather station, which recorded every ten minutes.
We selected +,- rainfall event data from +330 to+333.
The rainfall energy factor was calculatedusing the equation of Wischmeier and Smith(+312) as follows :EIEI-*ῌWhere E : total rainfall energy in metricoton
meter per hectare (t · m/ha)
I-* : the maximum -*-min rainfall intensity(cm/h)E was calculated as follows :EEkr῍Ek,+*23 logI῎
Where Ek : kinetic energy in metricoton meter
per hectare per centimeter of rain(t · m/ha/cm)
I : rainfall intensity (cm/h)r : rainfall(cm)Rain shower less than *./ inch and separated
from the other rain periods by more than 0
hours was omitted from the erosion index,
unless as much as *.,/ inch of rain fell in +/minutes. According to Wischmeier and Smith(+312), the value of ,23 (t · m/ha/cm) was applied for all intensities greater than 1.0 cm/h, so
equation (-) will be

3+  ,**,

Ek,+*23 log I for I1.0 cm/h
῏
Ek,23for I1.0 cm/h
ῐBecause energy computed in EI equation isexpressed in hundreds of metricoton per ha (t ·m,/ha/h), the erosivity index (R)becomes :R(EI-*)+*,ῑ,. . Soil loss measurement
The sediment in the ditch was pulled out into
a drum with a siphon, thoroughly stirring thecontents in the drum and quickly extracting/** ml sample with plastic bottle. By measuring the dry weight and the volume of runo#
water stored in the ditch, the soil loss in theditch was calculated as follows :Sd(A//**)Vd+,***
ῒ
Sd : total soil loss in the ditch (g), A : dryweight of /** ml water sample (g), Vd : volume
of runo# water in the ditch (liter), +,*** : conversion factor from ml to liter
The sediment in the tank was sampled andthe total soil loss in a tank (Sdr) was calculatedusing the same procedure as mentioned above.
Total soil loss from erosion plot in an individual measurement was converted into kg/ha as
follows :Soil loss(SdSdr1)+**+*ΐ+** : conversion factor from +** m*, to + ha,+*- : conversion factor from g to kg,. / Supporting data
Supporting data which also had been collected in this study were rainfall and co#ee growthparameters. Rainfall data were collected using
automatic rainfall recorder every ten minutes ;while co#ee growth parameters (height, diameter of canopy, and co#ee yield) were measured
directly in the ﬁeld for evaluating the competition between co#ees and weeds. The type of
weeds and co#ee growth parameter were observed by Sriyani et al. (+333).
,. /. + Weed vegetation
Although the weeds were cut regularly
every two weeks, some weed species were still
appeared in cleanoweeded plot. As presented
in Table , reported by Sriyani et al. (+333), thedominant weed species in cleanoweeded plot
was Ageratum conyzoides which was an annual῍ῌ : Soil Erosion under Co#ee Trees with Di#erent Weed Managements in Humid Tropical Hilly Area of Lampung, South Sumatra, Indonesia

Table ,

7

Type of weeds species found in each treatment

Clean-weeded plot

Paspalum plot

Natural weeds plot

Ageratum conyzoides
Borreria repens
Erechtites valeriaifolia
Imperata cylindrica
Oxalis barrelieri

Paspalum conjugatum
Polygala paniculata
Hedyotis auricularia
Ageratum conyzoides
Borreria repens

Clibadia surinamense
Clidemia herta
Chromolaena odorata
Melastoma a$ne
Imperata cylindrica

herb. Instead of Paspalum conjugatum, a few
weed species also occurred in Paspalum plot
including Polygala paniculata, Hedyotis auricularia, and Ageratum conyzoides. Clibadia
surinamense (woody species) whose mean plantheight reached +-0 cm was the dominant species (occupy 32ῌ of the total number of weed
species) in natural weeds plot. The photos ofdominant weed species were shown in Fig. ,.
The weeds started to cover the entire groundsurface (+**ῌ covered) around March +330 at
Paspalum plot and on April +330 at naturalweeds plot.
After that, the weeds weremanaged by spot weeding with diameter + maround the co#ee tree, and the coverage of
weeds, the ratio of the area occupied by weeds
to total areas, was calculated as 03ῌ. So,
during the experiment period, the weeds covered the soil surface between 03ῌ (after spot
weeding) and +**ῌ (before spot weeding).
,. /. , Co#ee growth
The existence of weeds has inﬂuenced on theco#ee growth. The conventional weed management (cleaning up weed) gave the best performance of co#ee growth as shown in plantheight, canopy diameter and coverage. The
weeds had suppressed the co#ee height at
Paspalum plot about .*ῌ and at natural weeds
plot about -*ῌ. The canopy diameter was also
suppressed as much as /1 ῌ at Paspalum plot
and /. ῌ at natural weeds plot.
Due to the bad performance of co#ee growthat both weedy plots, the co#ee yields of theweedy plots were very low. As reported by
Sriyani et al. (,***), the yield reduction ofco#ee beans in weedy plots in +333 was .*ῌ at
Paspalum plot and 1/ῌ at natural weeds plot

Fig. ,

Dominant species of weed in each experimental plot.



8

Table -

3+,**,Rain erosivity data during . years experiment

Year ofexperimentR(t · m,/ha/hr)

Rainfall
(mm)

+st
,nd
-rd
.th
Total
Average

-2/40
/++40
+/.1423,,4*--014*
2.+42./04++*1.4,+10242+,.24/./.140++-043

Average Rainfall
from nearest
rainfall station*
(mm)+23-42* Calculated from , rainfall stations (Pajar Bulan and SumberJaya) for rainy season data (Nov4 to May) from +31.+332

compared to cleanoweeded plot.
-.

Results and Discussion-. + Rainfall Pattern
Table - shows that the total rainfall during
four years of experimental period was ./.1.0
mm, with ++-0.3 mm per rainy season. This
rainfall was lower than average rainfall occurring in this area, i.e. +23- mm per rainy season(Afandi et al., +333) since El Nino’s occurrencein +331 caused a long dry season with low
rainfall. In addition, due to plot construction
during the ﬁrst year, the experiment beganlate, in February +33/, whereas the rainyseason usually occurred from October to April
or May.
The daily rainfall distribution (Fig. -)showed that .2ῌ of the rainfalls occurred lessthan / mm/day or about 0-ῌ was less than +*mm/day. Based on the equation (3) describedlater, about -1ῌ of the daily rainfall could be
categorized as the daily erosive rain (+*.3
mm/day).
The maximum intensity was ,* mm in +*minutes or +,* mm/h, which occurred at March0, +333. According to Hudson (+310), the soil
erosion will be occurred if rainfall intensity,/ mm/h, and as it was shown in Fig. ., only+.ῌ of the rainfall intensities which were calculated based on +*-minutes time interval
could be classiﬁed as erosive (,/ mm/h).
The maximum daily rainfall was 2, mm/day
occurred at January +1, +332, which almost con-Fig. -

Distribution of daily rainfall.

Fig. .

Distribution of rainfall intensities basedon +*-minutes time interval of rainfall.

Fig. /

Pattern of rainfall Indonesia, occurredat January +1th, +332.

centrated in two hours and its maximum intensity was +-./ mm in +* minutes or 2+ mm/hr.
As shown in Fig. /, this rainfall was fallen in /῏῎ : Soil Erosion under Co#ee Trees with Di#erent Weed Managements in Humid Tropical Hilly Area of Lampung, South Sumatra, Indonesia

hours, with intermittent pattern ; twenty
minutes after the rain started, it stopped, andbegan again for about two hours and ten
minutes. The intermittent pattern is a typicalrainfall in this area, so several rainfall events
could occur in one day. Due to this rainfall
character, the rain which fell later could be
more erosive although smaller than the previous rainfall, because the soil has been alreadywet and easy to disperse.
-. ,. Erosivity Index
The value of erosivity index ranged between-2/.0῏+/.1.2 and was tabulated in Table -.
Since the measurement period for each rainyseason is not the same, the erosivity values
di#er much. In the ﬁrst year experiment, themeasurement period was only two months dueto the erosion plot construction. A long dry
season due to El-Nino occurred during thesecond year of experiment until the end of +331,
thus the amount of rainfall was meager although the length of the rainy season was
normal. Hence, normal value was probably
found in the third and fourth year of measurement, and the values were +,/.1.2 and 3,,.* (ton· m,/h/ha) respectively.
The rainfall erosivity index as calculated inequation (0) proved to be the optimal rain parameter in Indonesia as indicated by Suwardjo(+32+) and Utomo (+323). Utomo (+323) reported
the values between 3+-῏+,0-- (ton · m,/h/ha) for
several areas in Indonesia which agreed with
the normal values in this experiment.
-. - Relationship between daily rainfall
and erosivity index
Based on +,- rainfall events from +33/ to +333
(Fig 0), a relationship between erosivity index
which was calculated using equation (.), (/),
and (0) and observed daily rainfall was derived
as follows :R῍+.0,. (Xῌ+*.3)
ῌ,with r ῍*.2,
Where R : daily erosivity index (t · m,/h/ha)
X : daily rainfall (mm)From this equation which shows the linear
relationship between R and X, it can be in-Fig. 09

Relationship between daily rainfall anderosivity index.

ferred that the rainfall will be erosive if theamount of rainfall exceeded +*.3 mm per day.
Due to the fact that the rainfall data available
in Indonesia was mostly daily rainfall, someresearchers had proposed rain erosivity index
using daily rainfall data. The rainfall erosion
index widely used in Indonesia as rainerosivity factor for applying USLE was introduced by Bols (+312) as follows :EIm῍0.++3 (CHb)+.,+ (HH)ῌ*..1 (CH,.)*./῎
῍
where :
EIm : monthly rain erosivity index (t · m,/h/ha)
CHb : monthly rainfall data (cm)
HH : monthly rainfall event (days)
CH,. : the amount of maximum rainfall in ,.
hours during one month (cm)
Applying the observed rainfall data to equation (+*), the values of EIm between /-, and-,-1* (t · m,/h/ha) with a mean of +,2./(t · m,/h/ha) were obtained in this experiment. These
values were two fold higher than Wischmeierand Smith’s rain erosivity index (equation (.)
and (/)). As shown in Table -, the Wischmeierand Smith’s rain erosivity index ranged from
-2/.0 to +/.1.2(t · m,/h/ha) with a mean of 2.+.2(t · m,/h/ha). An estimated rain erosivity index
between 3** and ,,/** (t · m,/h/ha) were also
found for Lampung areas (Manik and Afandi,+332) that were also higher than the values
found in this experiment.
-.. Surface runo#
The presence of weeds as well as the diameter of co#ee canopy inﬂuenced the runo# ratio
very signiﬁcantly. As shown in Table ., in the  3+

10

Table .
Rainy
SeasonPeriodRuno# and runo# ratio of each rainy season

Rainfall
(mm)

Runo#
(mm)
Cleanweeded

+st
,nd
-rd
.th
Total

30 Jan.30 Apr.
30 Oct.31 Apr.
32 Jan.32 Jun.
33 Jan.33 Jun.

,**,

Runo# Ratio(ῌ)

Paspalum

Naturalweeds

Cleanweeded
+/43
34*
340
14*

.0140
+*124,+1034.
+,.24/

1.4/
314/+034214-

042
*4/
*4*
*4*

.,4+
-4024*4*./0-41

.,240

14-

++-41

ﬁrst year of experiment, the average runo#
ratio was very high (+/.3ῌ, +./ ῌ, and 3.* ῌ forcleanoweeded plot, Paspalum plot, and naturalweeds plot respectively) compared to the otheryears, since the soil surface was relatively
open. The runo# ratio from the second to
fourth year experiment was 3.* ῌ, 3.0 ῌ and1.*ῌ for cleanoweeded plot ; *ῌ for Paspalum
plot ; and *.-ῌ, -.3ῌ and *ῌ for natural weeds
plot.
Although the total runo# of cleanoweeded
plot increased during the second year of experiment, its runo# ratio decreased due to theincrease of the co#ee tree canopy. The increasein co#ee coverage also reduced the runo# ratio
in the fourth year of experiment although therainfall was fairly high.
The runo# ratio for cleanoweeded plot was
higher than that found by Gintings(+32,) in
Sumber Jaya areas. Without cover crops, hefound a runo# ratio of +.12ῌ for +ῌyears old
co#ee with /30-ῌ slope gradient, and -.-3 ῌ
for -ῌyears old co#ee with slope gradient 0,00ῌ.
It was interesting to note that the Paspalum
conjugatum and natural weeds could reduce thesurface runo# drastically.
Paspalum conjugatum is a grass weed type, so the canopy
fully crept over the ground surface and its rootsystem was very dense and large. As a consequence, Paspalum conjugatum could intercept
the rainfall e#ectively and would act as runo#
barrier, thereby inhibiting the surface runo#
signiﬁcantly. Since the internal drainage ofPaspalum
+4/
*4*
*4*
*4*

Natural
weeds
34*
*4-43
*4*

soil proﬁle was very good, the runo# water
would inﬁltrate into the soil.
As shown in Table ,, a weed of tree typecalled Clibadia surinamense was present at natural weeds plot and could behave as a shadingtree. As consequence, the soil surface was not
fully covered with grass weeds type, so thesurface runo# was greater than Paspalum plot.
The e#ectiveness of cover crop in reducing
runo# was clearly shown in Table ..
In
Paspalum and natural weeds plot, the increasing of rainfall did not increase runo# height.
However, there exists a tendency in cleanῌ
weeded plot that runo# height would increase
with rainfall.
-. / Soil loss
The amount of soil loss in every month andthe total soil loss during the experimental
period are shown in Fig. 1, Fig. 2, and Table /.
In the ﬁrst year of experiment, the soil loss
from each treatment during the three months
observational period (FebῌApril +330) was asfollows : 2.2 t/ha in cleanoweeded plot, ,.1 t/ha
in Paspalum plot, and +./ t/ha in natural weeds
plot. Before the weeds covered the groundsurface, there was a little di#erence in soil loss
as shown in February +330 ; soil loss from
Paspalum plot was higher than the other plots
due to the fact that the ground surface was notcovered yet and was disturbed by transplanting Paspalum seedlings at this plot. One month
later (March +330), this situation was changed
drastically after the weeds began to cover the
ground surface ; the soil erosion from clean-῍ῌ : Soil Erosion under Co#ee Trees with Di#erent Weed Managements in Humid Tropical Hilly Area of Lampung, South Sumatra, Indonesia

Fig. 1

Fig. 211Monthly soil loss under co#ee tree with di#erent weed management.

Soil under co#ee tree with di#eremt
weeds management.

oweeded plot increased sharply.
The second year experiment began in October +330 and continued until April +331. The
soil loss from co#ee plot with general weed
management (cleanoweeded plot) in the second
year of experiment was ,,.1 t/ha, however it
could be *.*,2 t/ha if covered with Paspalum
conjugatum and *.+0 t/ha in natural weeds plot.
The weeds had already covered totally theground surface in Paspalum plot and naturalweeds plot (+**ῌ covered). However there
were big di#erences in weeds species (Table ,),which a#ected the amount of soil loss.
Paspalum plot was dominated by Paspalum
conjugatum, which was very e#ective in preventing soil erosion due to the fact that groundsurface was covered densely with Paspalum
whose canopy and root system would act as

runo# barrier and catch the direct raindrops
and prevent surface runo# from ﬂowing overthe ground surface. The natural weeds were
dominated by woody species and not so dense
compared to Paspalum plot. Thus, a chance forrainfall to pass the canopy and overﬂow on the
ground surface among the weeds existed.
Due to the long dry season in +331 because of
El-Nino e#ects, the third observation began in+332 for rainy season of +331/+332 and thefourth observation began in +333 for rainyseason of +332/+333. The soil loss from co#ee
with weeds was very small compared to cleanoweeded plot. The soil loss in +332 from cleanoweeded plot was 3.+ t/ha followed by naturalweeds plot *.01 t/ha, and no erosion was foundin Paspalum plot. In +333, the soil loss fromcleanoweeded plot was ..2 t/ha, and there wasno soil loss in both weedy plots.
Compared to the other research data with
di#erent crops in Indonesia, the soil loss fromthe co#ee areas was meager. However, comparing with the ﬁndings of Gintings (+32,) in
co#ee areas in Sumber Jaya, soil loss appeared
higher. The maximum soil loss in this experiment was found in cleanoweeded co#ee asmuch as ,,.1 t/ha. Utomo (+323) reported thatthe soil loss from a bare plot could be .,- t/ha.
During the four years experimental period
from +310 to+32*, Abujamin et al. (+32-) foundsoil loss from bare plot to be +3-./ῌ./, t/ha.

12



However, they also reported that the use of
Bahia grass (Paspalum notatum) strip with + m
width could suppress soil erosion to zero in thesecond and third year of experiment, whereas*./ m strip of Bede grass (Brachiara decumbens)
suppressed soil erosion until zero after the
fourth year of experiment.
Gintings (+32,) found that the soil loss from+ῌyear old Robusta co#ee with /30-ῌ slope
gradient was +.3. t/ha which was very low
compared to the soil loss from cleanoweededco#ee (,,.1 t/ha). On the other hand, the soil
loss from -ῌyears old co#ee with slope gradient0,00ῌ measured from May to October was+./1 t/ha (Gintings, +32,), which was lower than
the soil loss from cleanoweeded co#ee withsimilar age which was 3.+ and ..2 t/ha.
The e#ect of co#ee canopy on reducing soil
loss was demonstrated clearly in Fig. 2 and Fig.
3. Table . showed that in cleanoweeded plot,
runo# was ﬂuctuated but almost constantfrom the second to the fourth year of experiment. However, the soil loss tended to decrease
as shown in Fig. 2. It means that although theruno# ratio was relatively unchanged after thesecond year, the sediment which carried byruno# became smaller year by year as shownin Fig. 3. Increasing the co#ee canopy was the
major factor that was responsible of these phenomena. The co#ee canopy intercepted therainfall, hence the raindrops did not directly
strike the soil surface and soil aggregate did
not disperse, so runo# would carry less sediment.
-. 0 Soil loss tolerance
As shown in Table /, the soil loss from thisexperiment was very low ; the total soil loss
from cleanoweeded plot was around ..30 mm
for four years experiment or +.,. mm per year.
This value is below the soil formation rate inIndonesia, which is estimated about , mm per
year (Shah, +32,). If we took the average soil
loss only for three years observation (because
the +st experiment started too late), the average soil loss was around +,.31 t/ha or +.-/ mm/
yr. This value was also lower than the soil loss

3+

,**,

Fig. 3

Sedimentation of each plot.

Table / Total soil loss under co#ee with
di#erent weed management
Unit (mm)Year of
Clean-weeded
observation
plot

Paspalum
plot

Natural weeds
plot

+st
,nd
-rd
.th

*43+
,4-0
*4/*
+4+3

*4,2
*4**
*4**
*4**

*4+0
*4*,
*4**
*4*1

Total

.430

*4,2

*4,/

Average(mm/year)

+4,.

*4*1

*4*0

tolerance for that area which was estimatedbetween ,./-.1 mm per year (Manik et al.,+331) or ,,.. t/ha per year for Indonesia (Utomo,+33.).
..

Conclusion

The four years soil erosion research conducted in a hilly humid tropical area of
Lampung, Indonesia, showed that only +..,ῌ
of rainfall intensities could be categorized as
the erosive intensity (,/ mm/h). The maximum rainfall intensity was +,* mm/h, and the
maximum daily rainfall was 2, mm. A relationship between rainfall erosivity index (R : t · m,/ha/h) and daily rainfall (X : mm) was determined as follows :R+.0,. (Xῌ+*.3)
Soil loss from cleanoweeded plot ranged
from ..2 t/ha to ,,.1 t/ha. The total soil loss
from cleanoweeded plot was ..1* mm during
the four years experimental period, and +.+1῍ῌ : Soil Erosion under Co#ee Trees with Di#erent Weed Managements in Humid Tropical Hilly Area of Lampung, South Sumatra, Indonesia

mm/year was lower than the soil formation
rate in Indonesia.
The use of Paspalum conjugatum and naturalweeds as cover crop under co#ee trees wasvery e#ective in controlling soil erosion. The
soil loss from Paspalum plot was ,.1 t/haduring the ﬁrst year of experiment and becamezero after the third year. However, the soil loss
from natural weeds plot in the ﬁrst year was +./t/ha and zero after four years. Instead ofweeds coverage, the reduction of soil loss after
three years experiment was also caused byco#ee canopy through its rainfall interception.
The presence of weeds and the increasing of
co#ee canopy as the co#ee growth inﬂuenced
the runo# signiﬁcantly. Paspalum conjugatum
could suppress runo# until zero after the thirdyear of experiment, and in case of naturalweeds it suppressed until zero after four years.
Runo# in cleanoweeded co#ee decreased year
by year due to co#ee canopy growth, andruno# ratio became almost constant around 1ῌ
+*ῌ after the second year of experiment.
Both weedy plots showed the bad performance of co#ee growth. However, the use of
Paspalum conjugatum as cover crop in co#ee
garden was promising if managed optimally.
Since Paspalum has a shallow roots, it competes with co#ee’s root, thus these species haveto be introduced when the co#ee trees havegained enough height (about three years old).
Paspalum could be planted along strips between the co#ee plants or around the co#ee
canopy.
Acknowledgments
Appreciation is extended to Ministry of Education, Culture, and Sport of Japan, for funding
this study, and also to Dr. N. Sriyani, Mr. H.
Suprapto, Mr. H. Susanto, and Mr. A.T. Lubis
for supporting the weeds and some co#ee data.
Reference
Abujamin, S., Adi, A. and Kurnia, U. (+32-) : Permanent grass strip as one of soil conservation
methods. Soil and Fertilizer Research News,
Center for Soil Research, Ministry of Agricul-

13ture, Indonesia, + : +0ῌ,*. (in Indonesian).
Afandi, Gafur, A., Swibawa, I.G. and Purnomosidhi,
P. (+333) : Baseline biophysical information
about the Tulang Bawang watershed area,
North Lampung. Proceeding of the Management of Agrobiodiversity in Indonesia for Sustainable Land Use and Global Environment
Beneﬁts. ASB-Indonesia Report Number 3.
Bogor, Indonesia : 10ῌ+3,.
Bank Indonesia Bandar Lampung (,***) : Financial
economicῌmonetary statistics for Lampung
Province Region : p. ,/. Bank Indonesia Bandar Lampung.
BPD-AEKI Lampung (Indonesian Association of
Co#ee Exporter Lampung Branch) (+330) : Experience of marketing and the prospect of
Lampung co#ee : pp.+0ῌ-2. Roadshow of Technology of Arabica co#ee development in Western Lampung, Liwa, Western Lampung, January (in Indonesian).
Bols, P.L. (+312) : The Iso-erod on Map of Java andMadura, Soil Research Institute, Minsitry ofAgriculture Indonesia, Bogor.
Gintings, A.G. (+32,) : Surface run-o# and soil erosion under co#ee plantation and natural forest
at Sumber Jaya-North Lampung. Forest Research Institute, Ministry of Agriculture Indonesia, Report No. -33 (in Indonesian).
Hudson, N.W. (+310) : Soil conservation. Batsford
Ltd, London.
Manik, K.E.S., Susanto K.S. and Afandi (+331) : Estimation of allowable soil loss in two dominantsoil in Lampung. Journal of Tropical Soils II(.) : 33ῌ+*0 (in Indonesian).
Manik, K.E.S. and Afandi. (+332) : Rain erosivity
index in Terbanggi Besar, Central LampungAnalysis at three long dry seasons. Environment and Development +2(.) : ,2,ῌ,21 (in Indonesian).
Pudjiharta, A.G. and Pramono, I.B. (+322) : Runo#and soil erosion under natural forest stands
and co#ee plantations at Tabanan, West Bali.
Forest Research Bulletin .32 : +ῌ2 (in Indonesian).
Shah, M.M. (+32,) : Economics Aspects of soil erosion and conservation. Technical Note No. ,1.
Centre for Soil Research, Bogor, Indonesia.
Soil Survey Sta# (+332) : Keys to soil taxonomy 2th: p1-. United States Department of Agriculture. Washington D.C.
Sriyani, N., Suprapto, H., Susanto, H., Lubis, A.T.
and Oki, Y. (+333) : Weeds population dynamics in co#ee plantation managed by di#erent
soil conservation techniques. Proc. of International Sem. Toward Sustainable Agriculture inRS9l3¶ ¹ 3+ º ,**,

14

Humid Tropics Facing ,+st Century. Bandar
Lampung, Indonesia, September ,1῏,2 : /+-῏/,*.
Sriyani, N., Suprapto, H., Susanto, H., Lubis, A.T.
and Oki, Y. (,***) : The development of sustainable biological production technologies
harmonized with regional environmental conditions in East Asia. Final Report of the Greatin-Aid for Creative Basic Research from Ministry of Education, Culture, and Sport of Japan :+3.῏+31.
Suwardjo (+32+) : The role of plant debris for soil

and water conservation in annual farm land.
Ph.D. desertation. Bogor Agriculture University, Bogor, Indonesia (in Indonesian).
Utomo, W.H. (+323) : Soil conservation in Indonesia, a record and analysis. Rajawali Press, Jakarta (in Indonesian).
Utomo, W.H. (+33.) : Erosion and Soil conservation.
IKIP Malang, Press Malang (in Indonesian).
Wischmeier, W.H. and Smith, D.D. (+312) : Predicting rainfall erosion losses. A guide to soil conservation planning. USDA Agric. Handbook
No. /-1, Washington D.C.

ῌ   
ῌ
 ! "#$#%&' ()*+
 *ῌ  *ῌ  *ῌ  *ῌ **ῌ !"# ***ῌ$ %& **** '()*+*,** -.)*+*,*** /0)*1234*,,-

567ῌ8'9'(:;<=> +330 ?@A +333 ?9BC9DE> FGHIJKL
3M9NOPOQ@A9RSTUVWXYZ[V\]^_I` abcd> ῌ XYe9JK\fghK_
INOPOQ> ῍ ijklW_=JKm Paspalum conjugatum nXYe\ij_INOPOQ> ῎ opkq9JKnXYe\ij_INOPOQnrs` JK9L3d , tE: + u9ῌvnwHI` abc ῌ ndXYe9JK\fg:hx_> yz9abc ῍ W ῎ ndNOPO{|}9~ + m 9}\hK_I` ]^DE:;sXc9) BVd 2, > ) +* EBVvd +,* mm/h n
rHI` _@_> gB9 +..,῍ 9)Bv> RSTUq9WGsBv ,/ mm/h
\uH=<I` USLE n<AsB R m, · t/ha/h W BV X mm 9E:d> +.0,. X+*.3 9z!HI` fghKc9Z[d 1+/῍ 9}n _> NOPO9{¡9¢:W£GH=¤¥_I` JK:¦H=XYe\ij§sWXYZ[d¨_©¤¥_> Paspalum
abcnd - ?ª9BC«9Z[ *῍ :GHI9:¬_> opkq9JKabcnd . ?ª@A
Z[ *῍ :GHI` RSTUV)WGHI9d , ?ª9BC9fghKcn> ,,.1 ­/ha nrHI` ijkl\®¯§sWRSTUd¨_©°±²> Paspalum abcnd - ?ª«@A> op
kq9JKabcnd . ?ª@ARSTUq_G@HI` fghKc9RSTUVdRS³:_=+ ?E: +.,. mm nrz>

5679RSq´v\MuH=<I`.#/# : NOPO> RSTU> Z[> µU¶
µ·?¸
µ3?¸

: ,**+ ? ++ ¸ +: ,**, ? - ¸ ,3
J. Jpn. Soc. Soil Phys.
B
No. 3+, p. +/ ,- ,**,


ῌ *ῌ**ῌ

**Inﬂuence of Temperature/Water Condition on the Acidiﬁcation Processof Sediment in Lake Kojima
Kaoru UENO*, Tadashi ADACHI** and Hajime NARIOKA*** The Graduate School of Natural Science and Technology, Okayama University,-῎+῎+ Tsushima-naka, Okayama 1**῎2/-*, Japan** Faculty of Environmental Science and Technology, Okayama University,-῎+῎+ Tsushima-naka, Okayama 1**῎2/-*, Japan
Abstract
In acid sulfate soils, the material which causes heavy acidity is sulfate ; mainly pyrite (FeS,),
produced from the sediments in the sea that contain a lot of organic matter and sulphuric acid andsubjected to heavy reductive conditions. In the process of sulphuric acid production, particularly in the primary acidity stage, chemical acidity and bacterial acidity act together.

Thesebacteria (Thiobacillus ferrooxidans and Thiobacillus thiooxidans) contribute a major role as catalysts.

The purpose of this study is to investigate the relationship between the acidiﬁcation

process and the temperature and water content conditions through an incubation experimentation. Results are listed as follows :(ῌ)

In +*῎/*temperature conditions, the soil was acidiﬁed more strongly at high tempera-ture by chemical oxidation accompanied by high evaporation rate.

The acidiﬁcation was

stopped when the quantity of evaporation became lower than the level of soil moisture.
(῍)

When keeping the water condition with almost no evaporation, the speed of acidiﬁcationis slow but continuous. At -*and at around-+.* kPa, the acidity is extremely strong.

The above results show that the speed of evaporation inﬂuences the acidiﬁcation process andmicrostructure of the soil matrix. Drying is also an important factor that inﬂuences acidity due
to bacterial activity.
Key words : acid sulfate soils, temperature, water content, acidity, microorganisms!VWX+B5NYS GZ[D\] !^D+    $_E;`*aB$J!FGHGI5 *  !"

78 5_ !bc <Ddef *bc= $%#$% &'() *+,-./012 !

*gf *Dh_Bf * <h_Bi:j!FGH

3456789:; <Dent and Pons, +33/=>
5?

*



GIP *= 5k2lE% h_B <m *noD

!@ABCDE9FGHGI` *no= i:5pqDE9rs9t:6uvwx<Pyrite ; FeS,= $J!> KLMNOPQRBSTU;E9y!Dyz89y! <Darrell et. al, +32, ; {|* }tgtg~g34 1**῎2/-* S -῎+῎+** }tg g 1**῎2/-* S -῎+῎+ :  % % Y% *% h_B



16

 +323    Table +

Fundamental physical and chemical
properties of sample soils      !"#! $% 
& ' ! (!)!($*+ ,-"./ 0123
45

ῑῌ+ ?@°  !)  

 3+ ¼ ',**,

 +6789 2:;<=./,ῌ ῐ῔῍῏῎ῒΐ,>+ ?@23A !) !"?@ BCDE#FF$%& '+332 'GH
 I(J) FKLM*  +2N
G,O6-PGH .Q <RSTUVW/
01 72X3 45 (<

 +SiCL '}±² +*῍
6Y0 'Mgῌm,,
,402\ ]^ LL 'kgῌkg
+4,*: ]^ PL 'kgῌkg
*4.2_`]^ SL 'kgῌkg
*4-: ³w Ip*41,}  A-14,+
pH 'H, O
14-0
pH 'H, O,
,4./
EC 'mSῌcm
+*4-, b@A 'wt.῍.
+4,*´µ¦¶V·V9 'de)f¸¢¹¶V·V9-AºIpῌ, mm P}b@~ '῍.-B ¡»C"A9+,+?@ !)  6Y0 7'Z[89 \ ]^ wL : ]^ wP _`]^ wS

;ab< w 6c= 'de)f9 pH 'H, O
+ : / pH 'H, O, EC '+ : / g6>?h)f"9ij!"  b@A-B
C"A9 'DE +30+

k

2N!"<  pH 'H,

O   FG6Zl m6noH.I<p3* qJK !"LMNO<=6 - r!"

 APs.t<4(4 !23  uv6l6m<w P896:<
14 E89 ,. ,. +!k/*} ( Z!


2Nn< ' ! $%'Thiobacillus ferrooxidans  k!

'Thiobacillus thiooxidans 'Wakao et. al, +32, ;,>, 89Q9

ZD +320 ;  +323 Z!

,>,>+ I(4P1( !!"1p -*} 'q +302 ;  +31+  , X~

RSI(4 ,1 2 !u
v6TU%<w  oxyzoῌ{|

?@ '

,o

W"<
4 r)

(\]^

 , kg 6V W"16 +* ,* -* -/ .* /*}wL '?@!" ; +.,* kg ῌ kg : 0 X~'s ; *./* kgῌkg 23_`]^ wS 2NI(t 's ;<1O.6RS

I(< 14 Y  !  k!Z!  ,2-*} .\[\] '^_+33- +( 23\]`a89. ! ./}-*}+/} ./:<+( -*.*} q1

]^ wP*.+/ kgῌkg (<  @u4W"

¡V

¢zV£v

¤



'+,*} + q +., kgf ῌcm, @u 2::<  +v ¤2N

Z! 23 k! w¥¦(:W"< -*} P6b1

 < p ¡V ¢zV£v ¤ 6u  u -/} E61(cEd< I¤ 6@ (x% +¤ p 6 -*}= E2(. {| es(2

1O.I( 46W"< W"§yp. qf SNO ?@m6

 {¨Wz': ]^  yys 6g,<1O.45<<w ENO<3 m6S 2NI mcE +, ?@

01 -*}23 /*}W" pH 'H, O + : / ECs!6h:< pH 'H, O + : / b< w 'kgῌkg'+ : / 6 , ©qf !"< !"{yW ?

!"i +*-*} 89 * + , . 2

@|*2NGH<  ª«46¬­%+0 ,+ i  -//*} Fjk6l * *>. + i + rῌ.{¨Wz®6,¯«/ + , . 2 +0 i(<<,>,>, "4P1( !!"!K(g 4P   1 : µ¶·¸¹º)ªV $©>EFῌ¦BC»¼

-ῌ ῎

17

῍

-+ 

   ῍+ 

 SiCL   pH  1.-0 !

+., wt.῍ "#$% &' ())*+,- ./ 0 12 34 5678))*+9:;<0=0><?-, @ABCDEF<+)GH
pH IJ  K῍+

 pH  L0EF

M $0 NO67 , P QR  S67TU 3*.. VF4 WXY Z[(\D]^ _-/` 67 /*` EM 3Kabc4  d\pH <(Y  ef]^ W ghij῏ῌ+<Y67 . P Q pH \D EBCklm]^ n -/` M .*` M.%8TU

Fig. +

m6 Q . P op /*` M pH \Dqr]^ns7t 2 P

u.%ef]^@ABCD$©> pH IJ

Changes in pH under di#erent temperature in drying condition.

v

.*`M -/` M8w ]^ns7t
+*` 67 -*` \EM 3Kac4  \EBC

kl pH \D]^nx/y d\ pH S -*,* -/ .* +* /*` Mz \/ pH <EFGH{c|(6

} W~ 

>  }  +)F 3Degree of acidity, op Da <>4

 K῍, Da SnklJR/)n|t< Da3pHmaxpHmin4ῌdῌ Da ; +)F pHmax ; ERa
|td pH S pHmin ; ERa |t pH \D]^neOJ pH S d ;pH \D]^neO>QP>  Y~ ,. ,. ,pH \Dn|/ d S<67 pH

῏ῌ,

8n +Da n/|tFig. ,

0S<n *.+ ot¡S@ABCD$©>+)F Da

Changes of soil acidity (Da) in drying
condition.

pHmin < QPd <0¢£¬M"¦ \D EFz m/ ­¤n

Da S +*` Md8\/ EMkl]^Z[®/(<"¦ EFz a -/` MSn</ / *.*--, *.*,,, *.*/+, *.*.3, *.*0-, *.+0+ kgῌkg  )n¤<¯tEFM8"¦ J  pH \D°

pH <"¦¥0

w GHK῍-.§  w-.** kgῌkg 67 +.2* kgῌkg ¨$©>@(% Se>ef0 "¦ *.,* kgῌkg .%8@A±%  34 ¦

AªV L0EFM $0 pH nWX W,²c 3K῍.4 32+.* kPa 3pF ..*4 oW ³´ghij 3pH 2.+,«2.--4

0<%\D]^ v(

18» 3+ ¼ ,**,

pH MNJO

ῌ/ #&'@ PG /*Q RS

ῌ/ a TUV 5) CD6W#KX/

R

YZ pH 3E[\O&'@ ?]) -*Qῌ*A /*kgῌkgῌSRῌ/ b !  ^ #;-3E[\

59V pH  / 12 _5J&`-'@ + RSῌ/ a a  bcd 5) pH J)C

D#ef`+B5)g +.,* kgῌkg R pH 3EhH)i=g jCD5) /*Q SR

ZhH

pH 3E[\O&`-'@kG -*Q Rῌ/b SR Z  TUV5) pH 3ElH) l-m# +.,*, *./*, *.+/ kgῌkg
f`V n3E[\#)od6p q3
O pH rZpm#3-sO&'@SRῌ/b a  bcd 5) CD#tu=]Y 2v
῏ῌ-$%CDE#F: pH

 w KL

Fig. -

Relation between pH and water content
in drying condition.

PGR Z# pH 3EhH)i=g PGReVr
wxf'@ ?ey# -*Q 5)SR#od6WpSRz{g#SR5)P-CD#F: pH 3E|&xf'@2v}~OB #:' GH (IJH Da O ῌ0 #&'@SR5) w+.,* kgῌkg #-` Da-*QDa/*Q
V GH#eV ,.* 69f'@ ?]# &` w
 *./* kg ῌ kg e *.+/ kg ῌ kg #-`) Da-*Q 
Da/*QV +.0+.3 6 f'@SR5) w+.,* kg ῌ kg #-` Da-*Q Da/*Q+.+ 6 59V w*./* kgῌkg-`) Da-*QDa/*Q
'
 qPs

*.+/ kgῌkg #

V +.2,.. 6 f'@

ῌ1 # Da  -*Q # : /*Q O

Sῌ*./* kgῌkg R

q3s Sῌ+.,*kgῌkg R 6) / #r& (I J#-`GHCD# :tuod-? O&`-'@?]/#:O  ῌ. ῏ῌ.
Fig. .

¹º

x/B:  (I Jqrg

p'CD w+.,* kgῌkg ) 0-+.* kPa ;59f'@soil moisture curve of sample soils.

 

ῌ.  *.,*

kgῌkg   !"#$%&

.ῌ ῍

῎

.A+ $%CD#F:GH (I J#-` pH 2

ῌ+ ) GHῌ|'()*#)+,&-J#y+N#eVI./ +33,  032.+ kPa pF -.* 123

3E:? O&`-'@ =/# ¡-45)6)7859:5 

!¢CD59:? x/ (£¤¥¦§¨¤;<=>:?
-A-&'@¥¦§O©ª«I¬­®I#eV¯&'+BCDE#F:GH (I JKz{ °¤¥ O ±/ +332

L'@ ' PGR´#F: pH µ¶) ·¸²³/]

{| : }~)*-+ῌtuvw ῌῌ/Fig. /

19

rstuvwb pH xy]

Changes in pH on three levels of water content.

ῌῌ0

rstuvwb)*+ Da

ῌῌ1Fig. 0Di#erences of soil acidity (Da) on threelevels of water content.

rstuvwb)*+ Da -+z

Fig. 1

Ratio of Da/*?/Da-*? on three levels ofwater content.

 

7, JK80LMN ,. ,. ,  45ῌ06 B&L pH  ! "#$%&'OP@Q( 7 !OP 9:RST#(

U-+V$%#( 9:, RSTU-+VW%X)*+ Da ,-+./0123#45ῌ,6

 7',80)9:0);<0=

>3( 77> -/? > Da

@AB#7

CDE( 80)FGH+.*?I-/? >3

YZ[\]*^_RS`

abE 4cXde& +3316( fg)* 4hi<:)6 jk1lm)nhi)

-+, +*o-1? >3p RSTU-+,m)

q@, -*oL=6 P 3+ ¼ ,**,

20

ῌῌ2Fig. 2@¹%L6

-/  -*   +330  
 -/  &LN"+,/+ %:8 09 LN
6%%"6,-. LWX %3k56 J  "JJ7

()"*+ -/

DaC?8kF   a Z'  +302

#$",-. .*

O»U

Types of soil acidiﬁcation in di#erent temperature.

!"#$"/0 -/





Ck% /*  .* ghZ"912*3456 !78009%:

 /S/ LN`a:NK"8  3;":8 % Da-*<Da.*<Da/*; k Z <`= "1

=> ? @AB"%CD+EF/0

v pH  6

GH%I J 0 ? @ %1@k LN

KA3;C@"3 L6MLN

>/0%:8

6 / 2X6 kC  Z%OP Q 09" KA=>LN b

JRST/ Uῌ2 "V/0 U  L

9  -*  -/  a % b  " 0.

WXLNYZ

1Lgh/¡ ¢ kCk LN

%[



. Ck% +*  ,* Z"

L"*\ 12%LN%OP:]

£v¡^_ `abCc N%de^f-/¢@kC 09 -*¤"3 <`= EF/0%C  gh"3.LijJk l() m^_"%k"nop"§@"*\ DN¨©%E"; N qῌr

@+A¥BCN¦ c

! st  q" "u#v"Z"C. 1Fª/0 1Fª/0Z 

A c$- 1w/ x%8 %&'

L pH  «¬/­9+0 LNF"(yv

ª/0Z  <`= *34? 56z{ +332 L L)|"u#/12 %} )|

~*)" c12$%8 % 12/0&'%(yv  +,LN%%"-"LWX/ u# J q" }x de/12  +, LWX \." J SL"*\ ¢®¯°/ G68`±0%/+L
G7C²="3.Hv %:80
.³,

IN´µ"*\ @%L6"+,@ /* ¶ <`=JJK51. <`=LM"GHv %CkL6F/012*34L6"JkGH/8  Uῌ/ %:80 6N -*ῌ6"N0"! %S L ῌ*./* kg ῌ kg ¶"9

¢LZNp%C . @ /*\@,kC " LN1,-.

}?

,SD0 3
SC.L6F %·Iv "%CD+LN6,-  LN

? ¸@ -* ¶  N´µ"3.<`=5

"%C2X/ ῌ +322 ; 34"¹`± L¶ L6N"}

+323 A/03;" L"u#v+CJ`±0%:8  M¶  ? ºῌ¶ : ·¸¹º»¼h2D $%FGῌVW@Aῌῌ3
Fig. 3 hiVW¢£;!0¥¦§ R¨©ST

Types of habitat of bacteria in di#erent water content.


 -*ῌ

Table ,

! ῌ*.+/ kg ῌ kg "# -*+.,* kg ῌ kg & *./* kg ῌ kg$% pH '()*+,-. /01+23. +24
566789 w:*.+/ kgῌkg #;!<= >?+@A56BCDE6
FGH Da IJ

!ῌ+.,* kgῌkg " $6

 Da-* KDa/* LM-NO# P",
Da-* QDa/* LM,- RSῌ0T U# FG@A

VW@AXYZ[U,/01\] <^ . pH I]_`UIa6
U/01\]<^ b6 cd R+302T #
e2Df2ghi/01+2# jkVW ῌ F

Gῌlm@A,-nop6q r$.
stu# VW ῌ FG

῍ῌ, pH /*21

LUIvwxyz

 hi2D{|}~ $%VW@A w:+.,* kgῌkg R-+.* kPaT # /01 

ª«¬­®;!®

Size of micropore and bacteria

¯°¬­®
RmmT

¯° pF

¯° fm
RkPaT

*4**4*3
*4-*

/4*
.4/
.4*

3,2+*4*
-,+*,4,
32+4*

*4/*
*43/
+4**

-4/

-+*4,

+4+3
+4/*
+42*
,4-2
-4**
34.3

-4.
-4-4,
-4+
-4*
,4/

;!®

±®
²®

+//4/
324+
-+4*³T ;! ; ´2;! RThiobacillus ferrooxidansT
fµ2;! RThiobacillus thiooxidansT

Iw668.- $%hiVW;! 8

kPaT hiVW REV T ,/01+2dV ,#+24,sῌ,# /015VW@A IJ, O.2xa stu,%U 9 R+33,T # 2Df2g#/01+2xhi

R-+.* kPaT ,¡9 UhiVW¢£¤#

$6 

pF -.* R32.+#&&E6V ./" d 3+ ¼ 2,**,3

22

ῑῌ+*
Fig. +*



`R¦8    H># JH F+7< X$ M #!"

 E7ML;  E=#$ 4n ,. ,. + L 
K"7I +L#$ F+7  fL"

#$ %

&' 

$ ( )

+,

0 /(1



-

./

2$ +32+3$ 456789:

N%" 2ch3Water thickness and bacterial motility.

*+$7;<$

=$ +,>:  

;<?@&AB  C$ D $ E !"o5I

'7N. w*.,* kg ῌ kg 

$ 4n ,. ,. ,ab(B  .IJ7O8*.+/ kgῌkg s 89  E;_#l32+.* kPa } 2hῐ.3 LM 
_

1_ 

F  2$ +33-3 'G ?@P+,&j$  `+= (B +

#$ ῌ FH>$ ῍ I$ IJ $ ῎,7CL;  E+, ;8& .

!K"LM 7$  #L# ῏$N%&OPQ7 ῐ, LM   #+,7 ;8LM $ E#  R<S LM  `+=#l-+*., kPa 3m 2d+.**¡

T./ U'"7M  #V( PIJ*./* mm3 XV(?LM  l32+.* kPa 3mL#$ V()7W ">X$ V(¢£i +,78<$

1  7*

J./ E#Y+ 2Takahashi andN%7¤QLM

  C$ V( ¥/$  {`Toriyama, +3323 C$ #,Z"["-LR¦8#§.$ +,`¨P

2hῐ+*3 E&

M1$ \]"5^_`+S

N%"

./*J7;<$ `+ab7 cde./   ;?@&0U'"#f$ l32+.* kPa 3m(B

I #T© ML; 
E  $ l32+.* kPa }V(= 2hῐ3$ 2c33

ECLg1X$  `+=*J (B L#$  ST&$ hῐ3

JPJU«/ `N%"¬VI

Ci/j.

2a3 #$  .IJ72k8l-+.* kPa 3m

=L$ 4n , .,. +(B o576pq/

7r$ 4n ,. ,. ,  +.,* kgῌkg s 2l-+.* kPa3
89./  l-+.* kPa #$ :t;<=>u`'ῌG7;<O8  JªI

1­<O8$  I"J#¬i/W® k.
<=«/ /ῌ ῍ ῐ ῏ ῎

vZ? M1$  `+7w=L <N% =

X1L#$ I"YI¯ I"JK"ῌ`+M  E=#$ x 1Pfu`@yzabST&ZX  i$ [I"YI¯$ G.AB. 7-{CD.

<$ .XPIIJ |PM  E 

LM °±²³\´´]^ (B µ¥ I"J&¶ 1_`.

ab#$ }~ 'G E.

+3 V(ab 2+*¡/*·  0 K"  I"J

2b3 #$ 2a3  2c3 #+=LM  2c3 #$ V

V(3,3 DC`+ab./$ w+.,*, *./*, *.+/ kgῌkg (7k 7 15F.=LM  G<+

- 7r`+ab&aC.$ -*· (,H|#

bLbH.d¸ I"JN%&O7<1$x¹º$  »7ZX«

1$ IIJ

7$ `+N%"7I .$(B) /*·  , K"a< : »¼ῌ  

 







 

 ?ῌ :; -/  

!"

w#*.,* kgῌkg $%32+.* kPa &' () )!*pH /* , 



2



/0 ( </= >

 3
 78

9"

2

-

!
" C

 ()D

"!" #$ %EF6
"!6 $' -G& 

E'*"F  () *HI+  ,* $-* %-+.* kPa &'" JK78< 0

( LM-. /NOPE  >

Dent, D.L. and Pons, L. J. (+33/) : A World perspectiveon acid sulphate soils, Geoderma, 01, ,0-῎,10.

 ? 0Q"1L2*R3<  HI   :;S



Z[



# ῍b .0 $.' : -,/῎--/.
VWX $+320' : "

-



> "*ῌHI Y /1 $-': ,/,῎,/0.

Z[\]ῌ^_` $+323' : ^Pa $

3' N /1 $-' : ,-1῎,.+.

ῌbῌTcῌ^ ?

 +*@/* 8   
6  7AB 1"  ):;*pH

AMERICA, Madison.

./0

56 w#+.,* kgῌ

kg $%-+.* kPa &' 



1

40  
 

 

   - -* ,+*, pp. -1῎/0, SOIL SCIENCE SOCIETY OF~T+U $+302' : ῌ῍ +



23

Pa $

ῌ^_` $+322' : -' N /0 $3' : 3*-῎3*3.

dXῌe?f $+332' : g x pp. 02῎12
1h ¡ S}x
V¢C $+30+' : ?

i-qLM^V¢C $+302' : £





¤ mn Y -3 $,' : ++0῎+,*.
(+32,) : BACTERIAL PYRITE OXIDATION I, J.
Gen. Appl. Microbiol., ,2 : --+῎-.-.
R.Y. ¥¡¦§ E.A. §¨©=oo $+331' :  1pqx pp. ++*῎+++ rsª S}x
7nX ῌ tRu ῌ vwW/ ῌ «xyz ῌ T
{ῌI;

|ῌyP¬} $+323' : ^­qLM

6 *UVW=F  XY =DZ[ 9~ῌ?*ῌ®

:

Y 0* $,' : +/+῎+/0.

HI ¯6 °¤ῌ± $+31+' : *῍lNario W., Masatoshi M., Yonekichi S. and Hideo S.

45 #$ 6 70HT8῎£ j k Y -, $0' : ,10῎,13.

HI-²_³4 "Z[ ῍b .3 : /-῎0*.

;<8U M\]=>^_1

P_ῌ ´ $+33-' : Thiobacillus ferrooxidans`a4b1?cd41@e1 f. gAhi

 T. thiooxidans

BCD8*f.jkDE*l8i¶ +*3 : //-῎//1.

" r-µ- vw

Takahashi, T. and Toriyama, K. (+332) : Role of Iron῏
FGHmῌI;nJῌopqLM

Oxides in Changes in Soil Microstructure withῌDrying and Redacting Treatments, Soil Phys.

KJ $+33,' : /=>? N<r +0, : 23῎30.
OP QῌstRu= $+330' :  vwb1x pp. /1
῎0* yz{| S}x
Darrell Kirk Nordstorm et. al, (+32,) : Acid Sulfate
Weathering SSSA Special Publication Number

Plant Growth, Jpn., 12 : -/῎.-.

yP+U= $+332' : +´ ·1x pp. 3+
῎3, ¸ S}x

yP¬} ῌ 

= $+32+' : Z[  x pp. +/.῎+// | S}x
S¹º : ,**,  + º . S4º : ,**,  / º + ῐ
J. Jpn. Soc. Soil Phys.
῏῍ῌῐῑ῎
No. 3+, p. ,/ῌ-2 ῍,**,῎Sediment Yield from Various Land Use Practices
in a Hilly Tropical Area of Lampung Region,
South Sumatra, Indonesia
AFANDI*, Bustomi ROSADI*, MARYANTO**, NURARIFANI**, Muhajir UTOMO*,
Masateru SENGE*** and Tadashi ADACHI***** Faculty of Agriculture and ** Faculty of Engineering, University of Lampung,
Jl. Sumantri Brojonegoro +, Bandar Lampung -/+./, Indonesia*** Faculty of Agriculture, Gifu University, +ῌ+ Yanagido Gifu /*+ῌ++3-, Japan**** Faculty of Environmental Science and Technology, Okayama University,-ῌ+ῌ+ Tsushimanaka Okayama 1**ῌ2/-*, Japan
Abstract
Sediments transported from various land uses and entrapped by natural vegetative ﬁlter were
measured from January to November +333 in a hilly humid tropical area of Lampung, South
Sumatra, Indonesia. A very simple sediment trap made from a PVC pipe with diameter of +*.3 cm
was designed for measuring the sediment yield. Five types of land uses were chosen as follows :(a) co#ee garden in multistrata system followed by rain-fed agriculture and grass ﬁlter, (b)mixed-co#ee garden followed by short shrub ﬁlter, (c) clean-weeded co#ee garden followed bylong shrub ﬁlter, (d) clean-weeded co#ee garden, and (e) secondary forest followed by new forest
remnant. The measurement during eleven months showed that the mixed-co#ee garden produced the highest sediment yield (1+3.1g/m,), and the lowest sediment yield was derived fromsecondary forest area (*.*2g/m,).

The sediment yield from clean-weeded co#ee system wasaround 3-..ῌ,13.1 g/m,, and multistrata system indicated a low sediment yield (,.- g/m,). Although mixed-co#ee garden showed a very high yield of sediment, natural vegetative strips
entrapped 33.1ῌ of the sediment. The vegetative ﬁlter zone covered with grass (+./ m long) andshort shrubs (- m in length) could entrap 3-./ῌ and 33.1ῌ of sediment respectively, and the longshrub ﬁlter (+, m in length) could entrap only /,./ῌ of the sediment due to the concentrated ﬂow
in the longer slope. The surface cover condition of the land use system and farming activities(weeding, tillage, fertilizer application) indicated a high contribution on sediment yield than theother erosion factor.
Key words : sediment yield, co#ee, vegetative ﬁlter, Indonesia+.

Introduction

Forest scattering has been a major problem
in Lampung, Indonesia. The study conductedby Syam et al. (+331) at the upper part of Way
Besai catchment, West Lampung, showed thatin +31* the forest occupied /1..ῌ of that areas,
which became ,+..ῌ in +33*, on the other hand
the monoculture plantations (co#ee tree) in-

creased from *ῌ in +31* to .+.2ῌ in +33*.
During +332ῌ+333, the forest scattering in West
Lampung was very intensive due to the changeof government which caused the weakness oflaw enforcement as well as the increasing of
co#ee price in +333 ; the co#ee price increased
more than three times in +333. Most of protected forest areas in West Lampung have beenchanged into co#ee garden in a very short῏  3+

26time. Although the above land use change has
caused the deterioration of soil fertility asreported by Lumbanraja et al. (+332), the overall negative e#ects of this phenomenon on soil
erosion process, especially o#-site e#ect of soil
erosion, is still unclear. The abundance of natural ﬁeld border in this area, such as riparian,hedgerows, shrubs areas, as well litter which
covered the soil surface, could a#ect the transfer of erosion materials (sediment). The extent
of soil erosion material that will be transported
is highly depended on whether the sediment
meets something that can block its ﬂow, so theposition of vegetation in landscape is more
important than the percentage of coverage. Although soil erosion rate from various land uses
types can be easily measured using erosion
plot studies, however, in a landscape scale, theexistence of border strip has made the extrapolation of the results from erosion plot studies
di$cult.
This research emphasizes the sedimenttransfer across various types of land uses onco#ee culture based and natural ﬁeld border inWest Lampung, Indonesia. In this experiment,“point measurement” is used, and can bechanged into “spatial measurement” by multiplying with width and length of the areas
under consideration. The objective of this research is to know the extent of sediment transfer from various land use types and naturalvegetative ﬁlter.
,.

Methodology,. + Land Use Systems
The experimental ﬁelds were located at
Sumberjaya District, West Lampung, Sumatra
Island, Indonesia (Fig. +) with elevation between 1**2,* m above the sea level. Five
representative land use systems were chosen :(A) Co#ee garden in multistrata systemfollowed by rain-fed agricultural ﬁeldof horticultural crop with a grass ﬁlter,(B) Mixed-co#ee garden followed by shortshrub ﬁlter,(C) Clean-weeded co#ee garden followed by,**,

Fig. +

Location of experimental site.

long shrub ﬁlter,(D) Clean-weeded co#ee garden without
ﬁlter,(E) Secondary forest followed by new forest
remnant
Mixed-co#ee gardens consisted of various
trees with di#erent height in which co#ee was
the main vegetation (-*ῌ1/ῌ). Two mixedco#ee gardens were selected ; the ﬁrst had
nearly -*ῌ of co#ee trees with more diverse
trees, and the other was dominated by co#eetree (1/ῌ) with less various trees (A+ and B+
respectively in Table +). We designated A+ as“multistrata system” because the trees distribution is diverse, with di#erent height than B+.
The rain-fed agricultural ﬁeld (A,) was locateddirectly below the mixed-co#ee garden (A+),
and a narrow grass ﬁlter (A-) was situated at
the edge of rain-fed agricultural ﬁled.
Two types of co#ee garden with cleanweeded ground surface were chosen. One typehad a short slope of steep gradient (C+) with along shrub ﬁlter (C,) at the edge of this slope,and the other was consisted of two long slopes(D+ and D,) without vegetative ﬁlter.
The forest area was a secondary forest withvarious types of trees (E+). Below this forest
area, there was a new cleared land of forest
with ground surface covered by cutting trees(E,). We designated E, as “new forest remnant”

ΐῒ : Sediment Yield from Various Land Use Practices in a Hilly Tropical Area of Lampung Region, South Sumatra, Indonesia 27

The annual rainfall was around ,0** mm/year ; the rainy season is usually from November to May of the following year. The rainyseason was followed by weak dry season because usually rainfall still occurs more than +**mm every month. The daily average temperature was ,,ῑ and relative humidity was 21.,ῌ.
The period of experiment lasted from January+333 to November +333.
,. , Sediment Trap Equipment
The designed simple sediment trap (Fig. ,)consisted of four components as follows :(a) Sediment collector made of PVC-tube
with +*.3 cm diameter.
(b) Plastic funnel inside the L-tube.
(c) PVC tube with diameter 1./ cm ; the tube
was drilled with nine holes at the wallside, and one hole was connected tosmall plastic bucket ; a ﬁlter paper wasplaced at the bottom of tube and supported by a cloth.
(d) Small plastic bucket, consisted of ﬁlter
paper and cloth
Samples of sediment were collected at least
once in a week ; the frequency of sampling
depended on the amount of the rainfall. The
sample was collected by changing the ﬁlter
paper with a new one (known weight) andpacked into plastic bag. The sediment was
taken to laboratory, dried and weighed. Whenthe samples were too large, a sub sample wastaken.
Total sediment was calculated as follows :SaῐSe῎3῏SbῌSe : dry weight of sediment in the PVC tube(g)Sb : dry weight of sediment in small plastic
bucket (g)Sa : total sediment weight (g),. - Location of Sediment Traps
Three to ﬁve sediment traps were set up
respectively at the lower boundaries of theland use as follows :(A) ῎Multistrata systems with co#ee trees
and surface mulch (A+)῎Rain-fed agricultural ﬁeld in the valleys

Fig. ,

Structure of Sediment Trap.

grown with horticultural crops (A,)῎Grass ﬁlter zone (A-)(B) ῎Mixed-co#ee garden with short slope(B+)
῎Short shrub strip (B,)(C) ῎Clean-weeded co#ee garden before
shrub strip (C+)῎Long shrub strip (C,)(D) ῎Clean-weeded co#ee garden at upper
part of slope (D+)῎Clean-weeded co#ee garden at lower
part of slope (D,)(E) ῎Secondary forest areas (E+)῎New forest remnant (E,)
The description of each site is tabulated inTable + and those photos are shown in Fig. -.
,. . Analysis
The sediment yield was calculated by dividing the sediment caught in sediment trap withareas, i.e. the slope length times the width of
the sediment trap as follows :SyῐSaῌῌL῏W῍῍Sy : sediment yield per unit area (g/m,)
Sa : total sediment weight (g)L : slope length (m)W : width of sediment trap (ῐ*.+*3 m)
Because no exact boundaries were made, theaccuracy of soil erosion (sediment) entrappedby the sediment trap is more or less inﬂuenced

28

Table +
Code Land Use

NumberMultiStrata

co#eebananasjack fruit
guava
durianbeans
chilliA,

Rain-fed
agriculture

A-

Grass
(ﬁlter)small grass

B+

Co#ee
(mixed)co#eebananastrees

B,

Shrubs(ﬁlter)weeds(woodyweeds,
ferns)

C+
C,

Co#ee
Shrubsco#ee
weeds(woodyweeds,
ferns)

D+

Co#ee

co#ee

D,

Co#ee

co#ee

E+

ForestE,

Forest(open)

mixed(trees,bamboo,
rattan,etc.)
surfacecoveredwith falling
trees

,**,

Description of each representative land use

Name

A+

3+

main
+*
,
+
+* furrows

Vegetation
Height Distance
(m)
(m)
,
,
.
.
/

-,4/

Slope
(ῌ)

Length
(m)

Note

-1

3ῌ+*4/

surface covered by litter (,/ῌ) below thisland use is rain-fed
agriculture./+/ῌ,,4/Jan.-March (beans)
Apr.-June (cowpea/chili)
Jul.-Dec. (fallow)
A, was below A+*4*/ῌ*4+

dense

/ῌ3

+4/

A- was below A,
Sawah/paddy ﬁeld isbelow this ﬁlter

,
,
0

-,4/

,/

34/

dense

2,

-

Clean-weeded.
co#ee tree /*ῌ withother trees alternate between the co#ee tree
B, was below B+.
Sawah is below thisﬁlter.
The weeds were dominated by Clibadia surinamenses.

+40/

,,
dense

0/
3*

+24/
+,

Clean-weeded co#ee garden.
C, follows C+.
Creek is below this ﬁlter.
Clibadia sp. is dominated.

main

+40/

,,

.,

--4/

main

+40/

,,

.,

+-4/

Clean-weeded co#ee ﬁeld.
Clean-weeded co#ee ﬁeld.
D, was below D+.
Intermittent creek isbelow this ﬁeld

dense

3*

main
/
-

1*

-** Below E+ was E,
to the top.*
New at theJanuary, +333.

end

of

῍ῌ : Sediment Yield from Various Land Use Practices in a Hilly Tropical Area of Lampung Region, South Sumatra, Indonesia 29

Fig. -

Land use types.

by the place of location of sediment trap. Fivesediment traps were set up randomly in eachland use, one or two in rill and runo# pathways. That is why the data between replications is varied, with high standard deviation. It
was assumed that the sediment entrapped bythis equipment was representative of the soil
loss from the area with the width of sedimentcollector and slope length. In these methods,“point measurement” can be changed into “spatial measurement” by multiplying with theareas under consideration.
Since there were two or three types of land
use in one land use system, the sediment yieldof the second or third land use was calculatedusing the total length of upper slopes. The
following example shows the calculation of
sediment yield for A-land use system that consisted of multistrata (MS), rain-fed agriculture(RA) and grass ﬁlter (GF).
Figure . shows that the sediment yields
which deposited in grass ﬁlter (SaGF) was the  3+  ,**,

30

Fig. .

Multistrata system followed by rain-fed agriculture and grass ﬁlter.

result of soil loss from the whole areas (multistrata, rain-fed agriculture, and grass ﬁlter).
The calculation of the sediment yield in eachland use is as follows :SyMSSaMSῌLMSW
ῌ
SyMSῐRASaRAῌLMSLRAW῍
SyMSῐRAῐGFSaGFῌLMSLRALGFW῎
Where :SyMS : sediment yield from multistrata system (g/m,)
SaMS : sediment caught by sediment trap at
multistrata system (g)LMS : slope length of mulstistrata system (m)W : width of sediment trap (*.+*3 m)
SyMS-RA : sediment yield from multistrata andrain-fed agricultural system (g/m,)
Sa RA : sediment caught by sediment trap at
rain-fed agriculture (g)LRA : slope length of rain-fed agricultural
system (m)SyMS-RA-GF : sediment yield from the wholeland use system (multistratarain-fed
agricultural systemgrass ﬁlter) (g/m,)
SaGF : sediment caught by sediment trap at
grass ﬁlter (g)LGF : slope length grass ﬁlter (m)To test the e#ectiveness of the ﬁlter, a simple
comparison was made between the amounts ofFig. /

Distribution of rainfall
experimental period.

duringthethe sediment entering the ﬁlter (Se) and thesediment leaving the ﬁlter (So) as follows :Filter effectivenessSeSoῌSe
+** ῌ῏
Se : sediment yield entering from upper slope
to the ﬁlter (g/m,)
So : sediment yield leaving the ﬁlter for the
next land use system (g/m,)-.

Results and Discussion-. + Rainfall
The amount of rainfall during the experiments was +31/./ mm. The distribution of rainfall is shown in Fig. / and is not well distributed. A very low rainfall was found in
April although it was rainy season. A dry
season developed from July to September. The

ῒῑ : Sediment Yield from Various Land Use Practices in a Hilly Tropical Area of Lampung Region, South Sumatra, Indonesia 31

Table ,

Composition of soil fraction at the experiment site (*῍,* cm)*

No

Land use

Clay
ῌ

Silt
ῌ

Sand
ῌ

Texture
Class

+
,
.
/
0
1

Multistrata system
Rainfed agriculture (horticultural crop)
Mixed co#ee garden
Clean-weeded co#ee with ﬁlter
Clean-weeded co#ee-upper slope
Clean-weeded co#ee-lower slope
Forest (Mount Rigis)

//4.
.240
/24,
.24/
0*4/*4,
-24*

+,4/
+24.
+/4.
,*4+
+.4.
+24.
,.4*

-,4+
--4*
,04.
-+4.
,/4--4.
-24*

Clay
Clay
Clay
Clay
Clay
Clay
Clay loam*ῌ analyzed using hydrometer method

Table - Selected soil physical properties
No

+
,
.
/
0
1

Land use

Multistrata
Rainfed agriculture
Mixed co#ee garden
Clean weeded co#ee-long shrub
Clean weeded co#ee-upper slope
Clean weeded co#ee-lower slope
ForestBulk
Density(g/cm-)

Particledensity(g/cm-)

*431
+4++
*432
+4*+4*,
*432
*430

,4.2
,4/+
,4.0
,4.0
,4.2
,4.0
,4.-

Organic-C Dispersion
ratio*ῌ(g/kg)
.-41
,+43
-*4/
,142
,240
-/40
//4.

01
23
12
2/
2,
20
0*

*ῌ Dispersion ratio (ῌ)ῐ(clay῍silt) undispersed/(clay῍silt) dipersed῏+**amount of rainfall in May and June (starting
dry season) was ,// and +-, mm respectively, alittle higher than that of March and April (,.and 2, mm respectively) still in rainy season.
The rainfall erosivity index (R) in this area
could be approached by using equation proposed by Utomo and Supriyadi (+323) as
follows :Rῐ῎2.13῍1.*+ CHb
ῌ
R : monthly rain erosivity (t · m,/ha/h), CHb :Monthly rainfall (cm)Using this equation, the total erosivity index
during eleven months of experiment was estimated at +,23(t · m,/ha/h).
-. , Soil Properties
Based on the soil taxonomy by Soil Survey
Sta# (+332), the soil was classiﬁed as Dystrudepts, dominated by clay fraction whose
ranges are from -2.* to 0*.-ῌ (Table ,).
Due to the fact that the soil is still relatively

young (Inceptisols), the bulk density and particle density are relatively low, and the dispersion ratio is very high although the organiccarbon is high enough (Table -). The researcharea is located in the mountainous areas which
elevation between 12*῍2/* m, so the low temperature is enough to maintain the high organic matter in this area. The soil permeability is
di$cult to measure because the soil has swelland shrink properties, so many cracks arealways found in the soil proﬁle. From this fact,
it could be estimated that the permeability ofthe soil is very high or the internal drainage isvery excessive. The strong red color of the soil
proﬁle supports this fact. As consequence, theleaching process which carried soil particles
from upper layer is very intensive, and although the dispersion ratio is very high andthe soil could be classiﬁed as erodible, the soil
erosion by runo# water could be low.

32ΐῐ῎῔῕ῑ ῒ 3+ ῏ ῌ,**,῍Sediment Yield from each Land Use
system(+) Sediment yield from multistrata systemfollowed by rain-fed agricultural ﬁeld with horticultural crops and grass ﬁlter (A-system)
The sediment yield measured at lower
boundary of multistrata system, rain-fed agricultural ﬁeld with horticultural crops andgrass ﬁlter are shown in Fig. 0.
As shown in Fig. 0, the sediment yield frommultistrata system was very low.
Totalamount of sediment yield from multistratasystem was only ,.- g/m, in ++-months measurement, compared to the sediments caught by
the traps of rain-fed agricultural ﬁeld and grassﬁlter which were .,-., g/m, and ,0./ g/m, respectively. The sediment yield caught at rainfed agriculture increased +2. times than in
multistrata system, however, most of this sediment was deposited in grass ﬁlter. This experiment showed that although the grass ﬁlter
was very short (, m length), it could entrap the
sediments up to 3-ῌ (in Table .) of inﬂow, andonly small portion of sediment was transferredto the next system (rice ﬁeld).
It is interesting to note that the sedimentyield during the dry season was still very high.
As shown in Fig. 0, the sediment yield in May,
June, and July were higher than that of therainy season (January-April). Even for grassﬁlter, the major contribution of sediment yieldoccurred on July (about /+ῌ of all sedimentation for ++ months), although the monthly rainfall was low.
Tillage activity and time lag of sedimenttransportation may induce the above results.
During heavy rainfall event on rainy season,
the weeds and beans covered the portion ofground surface at rain-fed agricultural ﬁeld, so
this vegetation would reduce soil erosion process. Following the beans harvest in April, thefarmer began preparing the land for growing
chili and cowpea, and this land preparation
would have strongly a#ected the soil conditionand surface cover ; soil surface was clear andsoil structure was loose. This condition would-. -Fig. 0

Accumulation of sediment yield frommultistrata system followed by rain-fed
agriculture and grass ﬁlter (A-system).

Fig. 1

Accumulation of sediment yield frommixed-co#ee garden followed by shortshrub ﬁlter (B-system).

Fig. 2

Accumulation of sediment yield form
clean-weeded co#ee before entering
long shrub ﬁlter (C-system).

stimulate soil erosion process. Time lag of
sediment transportation will also inﬂuence sediment transfer, especially in the ﬁlter area. The
accumulation of sediment yield, which was
produced during rainy season, was transported
in the following dry season.
(,) Sediment yield from mixed-co#ee garden followed by shrubs ﬁlter (B-system)
As shown in Fig. 1, the sediment yield frommixed-co#ee garden and entrapped by shrubs῍ῌ : Sediment Yield from Various Land Use Practices in a Hilly Tropical Area of Lampung Region, South Sumatra, Indonesia 33

Fig. 3

Accumulation of sediment yield fromclean-weeded co#ee without ﬁlter(D-system).

Fig. +*

Accumulation of sediment yield fromsecondaryforestwithoutﬁlter(E-system).

Fig. ++

Cumulative sediment yield from various land use system.

ﬁlter were 1+3.1 g/m, and ,.- g/m, respectively.
The vegetative ﬁlter was dominated by woody
weed species, identiﬁed as Clibadia surinamenses. Ferns comprised the other species. Although the shrub ﬁlter was very steep (slope
gradient was 2,ῌ) and short (only - m), it wasvery e#ective to entrap the sediment from theabove system. Most sediment from mixedco#ee garden was entrapped in the ﬁlter (33.1ῌ
in Table .), and only small portion (*.-ῌ)
passed and transferred to the next land use(rice ﬁeld).
The biggest contribution of sediment fromthe mixed-co#ee garden occurred in October.
Due to abundance of water during rainyseason, weeds under the co#ee tree grew very
fast, so farmer began clearing weeds at the endof rainy season (May or June). Farmers cut theweeds using hoe. The hoe is struck into the soil
surface, so the weed roots will be truncatedfrom the soil. This activity would also be doneat the beginning of rainy season (early October), due to some reasons such as weeding activity and fertilizer application. Those tillage
activities could break and loose the soil surface, and enhance soil erosion due to detachment process by farmer hoe.
(-) Sediment yield from clean-weededco#ee followed by shrub ﬁlter (C-system)
Sediment yield from clean-weeded co#ee andentrapped by shrubs ﬁlter were ,13., g/m, and+-,.03 g/m, respectively as shown in Fig. 2.
The biggest contribution of sediment yieldfrom the ﬁlter occurred on October and November +333, about 01ῌ of total sediment yieldfor ++-months observation. It is fairly di$cult
to decide which process was responsible forhigh sediment transfer. Although ﬁeld evaluation showed that a rill has developed at theupper part of this sediment trap, an evidence of
sediment accumulation indicated that a smalllandslide might also be responsible.
The other possibility is the side e#ect of
weeding activity by the farmer. As commented above, the farmer usually has a lot of
activities at the end of rainy season and at the
beginning of rainy season, including weeding,fertilizer application, and soil tillage. As shownin Fig. 2, the results of these activities wereshown in the form of sediment yield, whichstill occurred in the co#ee garden during thedry season (July). During the next rainy

34ΐῐ῎῔῕ῑ ῒ 3+ ῏ ῌ,**,῍season, the sediment will be transferred to thelower slope.
(.) Sediment yield from clean-weededco#ee (D-system)
The sediment yield from upper and lower
slope of clean-weeded co#ee garden without
any conservation measure or vegetative ﬁlter
was 3-.0 g/m, and +/3.3 g/m, respectively as
shown in Fig. 3. Total sediment yield at lower
slope was greater than upper slope which suggests that sediment from upper slope made ahigher contribution to the sediment at thelower slope. Also of note is the ﬁnding that
before October, the sediment yield of upper
slope was always greater than that caught inthe trap of lower slope. As shown in Fig. 3,
major portion of sediment yield (.-.,ῌ) caught
in clean-weeded co#ee at lower slope occurredon November. Instead of farmer activities thathave been discussed above, the litter of co#ee
leaves also a#ected the sediment transfer
before November. As shown in Fig. -, the litter
had blocked the sediment trap, thus reducing
the transportation of sediment. After the
farmer removed litter because it was afraidthat the litters were used as insect nest, thesediment yield increased remarkably.
As
shown in Fig. 3, there is increasing sedimentyield in November +333, from -- g/m, in October to +/3.3 g/m, in November.
(/) Sediment yield from secondary forest
and new forest remnant (E-system)
Total sediment yield from forest areas andentrapped by new forest remnant were *.*2 g/
m, and *.0, g/m, respectively as shown in Fig.
+*. Although the slope is very steep (3*ῌ),sediment yield from secondary forest was very
low. The reduction of rainfall energy bycanopy of trees and the dense of vegetation at
ground surface that served as barrier were responsible of low sediment yield. However,about 0.3 times of sediment yield occurred
when forest was opened, but the value was still
lower than the other land use system measured
in this experiment. As shown in Fig. -, thesurface condition of new forest remnant was

still fully covered by litter,wood debris as well
as falling tress, which are still very e#ective inpreventing sediment transfer.
(0) Total sediment yield from various land
uses (F-system)
Total sediment yield from various land uses
during ++ months measurement are shown in
Fig. ++. The amount of sediment yield entrapped by each land use system was asfollows : the mixed-co#ee garden (1+3.1 g/m,) ;multistrata system followed by rain-fed agri
culture (.,-., g/m,) ; clean-weeded co#ee garden (,13.1 g/m,) ; clean-weeded co#ee garden
at upper and lower slope (+/3.3 g/m,) ; cleanweeded co#ee garden and long shrub ﬁlter
system (+-,.1 g / m,) ; clean-weeded co#ee
garden at upper slope (3..* g/m,). On the other
hand, the sediment yield from the forest areas
was almost zero (*.*2 g/m,) and which was entrapped by new remnant system was *.0 g/m,.
The multistrata system also produced a very
low sediment yield (,.- g/m,) and sediment entrapped by grass ﬁlter (which composed ofmultistrata and agriculture system above) was,0./ g/m,.
If the above unit changes into t/ha or mm(assumed soil bulk density + g/cm-), the valuesof sediment yield range from *.***2 to 1., t/ha
or *.****2 to *.1 mm. These values are lower
than sedimentation in some critical watersheds
in Indonesia reported by Utomo (+323). For
example, sediment yields in Way Sekampung
watershed, Cilutung, and Brantas were 2.1, 3.*,and *.,/ mm/year respectively.
In the current study, three co#ee garden systems produced di#erent amounts of sediment,
i.e. co#ee in multistrata indicated *.*,- t/ha,
clean-weeded co#ee indicated ,.2 t/ha and +.0
t/ha (at lower slope) and mixed-co#ee garden
indicated 1., t/ha. The highest value of sediment yield in mixed-co#ee garden was due tothe more intensive farmer activity in this land
use compared to the other co#ee land use
system.
The high value of sediment yield in mixedco#ee garden will not reach the stream since῎῍ : Sediment Yield from Various Land Use Practices in a Hilly Tropical Area of Lampung Region, South Sumatra, Indonesia 35

Table .

E#ectiveness of various natural vegetative strips in the
study area (*ῌ.* cm)

No

Description of ﬁlter+

Grass ﬁlter : consists of small grass and sparsebananas ; located at bottom of the slope (/ῌ3ῌ) ; +ῌm length. The sediment source is rain-fed agriculture
with horticultural crops.
Shrubs ﬁlter : consists of woody species (Clibadia sp.
and various ferns) ; located near at foot slope withlength - m and gradient of 2,ῌ. The sediment sourceis mixed-co#ee garden.
Shrubs ﬁlter : consists of woody species (Clibadia sp.
and various ferns are dominant) and small grass atbottom of this ﬁlter ; located at mid-slope with +, min length and gradient 3*ῌ. The sediment source isclean-weeded co#ee.

,-

33.1ῌ will be trapped by shrubs ﬁlter, and even
if it passed through the ﬁlter, the sediment will
be deposited in the next land use system,
paddy ﬁeld. This situation demonstrated theimportance of natural vegetative ﬁlter as wellas the arrangement or structure of land use
system in a landscape for soil conservation inco#ee areas in Lampung, Indonesia. Thisﬁnding was conﬁrmed by the experiment of
Sinukaban et al. (,***). Using a catchment’s
approach, Sinukaban et al. (,***) had shownthat the water ﬂow from that area relatively
remained constants although sharp land usechanges occurred in this area from forest toco#ee plantation during the years +31* to +33*.
In case of clean-weeded co#ee garden without ﬁlter (at lower slope), the sediment will
directly ﬂow into the creek and carried byrunning water. So from the viewpoint of soil
erosion process, the clean-weeded co#ee atlower slope has contributed the highest sediment yield. On the other hand, the multistratasystem produced a very low sediment yield,
indicating this is an optimal system to protect
soil against water erosion. Multistrata system
is very e#ective to reduce the rainfall energy
by intercepting raindrops before they strike to

Sediment
entrapped
(ῌ)

3-.1

33.1

/,./

the soil. Litter leaves that covered groundsurface also reduced surface runoff.
It appears that surface cover condition ofland use system provided a high contribution
on sediment yield other than the soil erosion
factors. Although forest area has steeper slope(3*ῌ) than clean-weeded co#ee garden (,/ῌ0/ῌ), they o#er better performance in modifying the erosion process. The e#ect of farming
activities (weeding, tillage) showed a high contribution in promoting sediment yield. These
activities had a#ected the soil surface condition, such as vegetation coverage and soil condition. If erosive agent could deﬁne soil erosion
process as detachment and transportation ofsoil particles, then the soil detachment process
has been done by the farmer activities.
(1) Filter e#ectiveness
Filter in general sense can include a range oflandscapes elements : depression, cut-o# drains,ditches, embankment, vegetated strips, hedgerows, and riparian vegetation (van Noordwijk
et al., +332). We recognized one natural vegetative strip which is abundant in the study area,
i.e. shrubs ﬁlter which consisted of various
weed species, mainly Clibadia surinamense andvarious type of ferns. Clibadia sp. is a woodyΐῐ῎῔῕ῑ ῒ 3+ ῏ ῌ,**,῍

36Table /

No

+
,
.
/
0
1
2
3
+*
++

Average of standard deviation (SD) and coe$cient of variation (CV)among the replications
Land use

Multistrata
Rain-fed agriculture
Grass ﬁlter
Mixed-co#ee garden
Shrub ﬁlter
Clean-weeded co#ee
Long shrub ﬁlter
Clean-weeded co#ee upper slope
Clean-weeded co#ee lower slope
Secondary forest
New forest remnant

Mean*
(g)

Standard
deviation**(g)

Coe$cientof Variation(ῌ),4/+.*24+
3-43
1//4+-4//-42
.-+
-.-4+
2+34,
,4,
,-4+

+421
-,043
3042
1/14-4,...4/
3*34+324,
/1042
,4/
.,4/

1/
,+*+**
32
2*
,++
/2
1*
+++2.

*῍ mean monthly during total experiment time (++ months)**῍ among replications for ++ months measurement

species that could reach +./ m in height. The
description of each ﬁlter strips is presented inTable .. All the vegetative ﬁlter strips fully
covered the ground surface. However, there
are several di#erences among the canopy typesof each ﬁlter. Grass ﬁlter could cover the entire
soil surface, however due to short height of thegrass, runo# water and sediment could still
ﬂow above the grass. Shrubs ﬁlter which was
mainly consisted of “woody species”, haveleaves and branches which could cover theentire ground surface cover, so it will be e#ective in protecting against raindrop. However,under the canopy of shrubs, the coverage on
the ground surface is not so dense, and runo#
water and sediment still could run between the“individual species”.
The e#ectiveness of natural vegetative ﬁlterin entrapping sediment was as follows : grassﬁlter 3-./ῌ, short shrubs ﬁlter 33.1ῌ and longshrubs ﬁlter /,./ῌ.
Instead of vegetation type inside the ﬁlter,the e#ectiveness of natural ﬁlter strip in entrapping or transferring sediment also depends
on slope length. This study showed that shortﬁlter cover with small grass or shrubs was very
e#ective to entrap the sediment than a very
long one. Runo# will have a chance to accu-

mulate in the longer slope, and a rill will becreated if there is a concentrated ﬂow.
(2) Variability
The sediment trap was very simple and very
easy to maintain. The data could be collected
on rainfall event basis or daily basis. However,
because the measurement has been done in thenatural condition, some weakness related tostatistical aspect is appeared. The variability
among the replications could be expressed by
calculating the standard deviation (SD) and the
coe$cient of variation (CV). The SD and CV
during the experimental period are shown in
Table /. The CV was very high, between ,-ῌuntil ,++ῌ.
The lowest variability was found in rain-fed
agriculture with horticultural crop (,-ῌ) due
to the fact that the farmer have cultivated thesoil as uniform as possible for growing a highvalue crops that need the same distance andgood soil management. A very high coe$cientof variation was found in long shrubs ﬁlter(,++ῌ), new forest remnant (+2.ῌ), and secondary forest (++-ῌ). At least there are threereasons why high coe$cient of variation
among the replications appeared : (a) the development of a concentrated ﬂow of runo# (or rill
erosion) above a sediment trap, (b) the farmer῎῍ : Sediment Yield from Various Land Use Practices in a Hilly Tropical Area of Lampung Region, South Sumatra, Indonesia 37

activity for cultivating the soil, and (c) and theexistence of litter at the ground surface, as
shown in Fig. -.
..

Conclusion

The existence of natural vegetative strips
was very e#ective in entrapping sedimenttransfer, and the e#ectiveness ranged between/,.,ῌ33.1ῌ. Although mixed-co#ee garden indicated the highest yield of sediment (1+3.1 g/m,), the sediment that left the whole mixed
co#ee garden system was very low (,.- g/m,)
due to ﬁlter entrapping. The lowest sedimentyield was found in secondary forest (*.*2 g/m,),and the highest values of sediment yield which
discharged into the river was found in cleanweeded co#ee garden as much as +/3.3 g/m,.
Co#ee in multistrata system also produced avery low sediment yield (,.- g/m,). The sediment yield values in this area were still lower
than the other place in Indonesia. The soil
covered condition of land use system andfarmer activities (weeding, tillage, and fertilizer application) gave a high contribution on
sediment transfer other than soil erosion
factors such as slope gradient and rainfall.
Since the measurement was made under natural condition, the coe$cient of variation
among the replications was very high. The
minimum value of coe$cient of variation was
found on rain-fed agriculture (,-ῌ) and the
maximum value was found on long shrubs
ﬁlter (,++ῌ).
Acknowledgments
We wish to convey our gratitude to the Inter-national Center for Research in Agroforestry(ICRAF) South East Asia, especially to ICRAF
sta# Dr. Meine van Noordwijk and Dr. Thomas
P. Tomich, and the Asian Development Bank(RETA /1++) for ﬁnancial support.
Reference
Lumbanraja, J., Syam, T., Nishide, H., Mahi, A. K.,
Utomo, M., Sarno and Kimura, M. (+332) :Deterioration of soil fertility by land usechanges in South Sumatra, Indonesia (from+31* to +33*) Hydrological Processes, +, : ,**ῌ,*+-.
van Noordwijk, M., van Roode, M., McCallie, E.L.
and Lusiana, B. (+332) : Soil erosion and sedimentation as multiscale, fractal process : Implication for models and experiments and thereal world. Soil Erosion at Multiple Scales :principles and methods for assessing causes
and impacts, ed. de Vries, P.W.T. Penning,
Agus, F. and Kerr, J. IBSRAM. CABI Publishing : ,,-ῌ,/-.
Sinukaban, N., Tarigan, S.D, Purwakusuma, W.,
Baskoro, T. and Wahyuni, E.D. (,***) : Analysis of watershed function : sediment transfer
across various types of ﬁeld boundaries. Final
Report. Bogor Agriculture UniversityῌICRAFSouth East Asia. Bogor.
Soil Survey Sta# (+332) : Keys to Soil Taxonomy,
2th ed. United States Department of Agriculture. Washington D.C.
Syam, T., Nishide, H., Salam, A.D., Utomo, M., Mahi,
A.K., Lumbanraja, J., Nugroho, S.G. andKimura, M. (+331) : Land use and cover changes in a hilly area of South Sumatra, Indonesia(from +31* to +33*). Soil Sci. Plant Nutr., .- : /21
ῌ/33.
Utomo, W.H. (+323) : Soil and Water Conservationin Indonesia, A Record and Analysis. Rajawali
Press, Jakarta.

=P1¹῎º » 3+ ¼ g,**,h38ῌ  
 *ῌ
*ῌ  **ῌ**ῌ  **ῌ***ῌ῏*****  !"#"$**  !"%"$*** &'!"#"$**** ()!"*+῎%"$!
,-./ῌ

"0 1234ῒ56789: ;<1=5῍ῌ>?@3AB1CD=ῑ

EFGHIJ KLMNO=PCDῑEFGQRIS6 PVC T,UOVWHIXYZ[\E]^H: _1 / `,U1=5῍ῌ/aEbc6d\HIJ QZef: gah ijklmV/a1nopoq:
rslt5: u@3: gbh mVlnopoq>vwx1yz?@3: gch {uHInopoq>|wx
1yz?@3: gdh {uHIwx|1}ZRnopoq: geh ~_ΐ>1~_ΐ: ORJ ++ 1FAB: mVlnopoq1=PCDῑ! g1+3.1 gῌm,h: ~_ΐAB1CDῑ
Z8 g*.*2 gῌm,hJ B6: {uHInopoqAB1=PCDῑ 3-..,13.1 gῌm, OR16
bH9: ijklmV/a1nopoqAB1=PCDῑ8 g,.- gῌm,hJ nopoq1ῐ
6KL?@3: 69nopoqAB1CD=P1!$EQR>OIJ+./ m 1wx|Eu@3 - m 1wx|Eyz?@3: ¡ῐAB1CD=P1

3-./῍: 33.1῍ EQR>OIJ ¢£: +, m 1|8wx|Eyz?@3: wx¤Oῐ¥s¦§QRIS6CD=P1 /,./῍ HAQR>OZAIJ ¨©x1?@MN6ª«9: ¬V­6R#V® g{u: ¬¯: °±h =PCDῑ6!Z²³E´«IJ#$%$ : =PCDῑ: nopo: ?@3: ,-./µ¶· ¸ : ,**+ · +*µ῎· ¸ : ,**, · /

,/ ¸
+- ¸


J. Jpn. Soc. Soil Phys.
BC tNo. 3+, p. -3 .1 ,**,





*ῌ*ῌ*ῌ *Soil water movement under micro-irrigation using a perforated tube
Shinpei NAKAGAWA*, Katsuyuki SOMA*, Jun’ichi KASHIWAGI* and Shinji SUZUKI**Graduate School of Agriculture, Hokkaido University
Abstract
E#ects of di#erent initial moisture conditions on the formation of wetted soil volume under
micro-irrigation were investigated in a layered soil having a plow layer and a subsoil layer withmacropores.

Water was applied at a constant rate of +** cm- min-+ for 1,* minutes using aperforated tube covered with vinyl mulch. Water application e$ciency was also evaluated fromsoil water storage and inﬁltration loss caused by bypass ﬂow
In the case of initially dry condition, the wetting front was spread in an elliptical shape with the
major axis in the downward direction. In the case of wet condition, however, the horizontal
boundary between the plow layer having high saturated hydraulic conductivity and the subsoil
layer having low one a#ected inﬁltration. Water reached to the boundary ﬂowed horizontally andinﬁltrated into the plow layer from the bottom. The amount of water inﬁltrated vertically was
more than that of horizontally inﬁltration in an imaginary main root zone. Inﬁltration loss beyond
the root zone due to bypass ﬂow was accounted for 23῍ in dry condition and 1/῍ in wet condition
for 1,* min respectively.

After 1* min irrigation, the rate of storage was unchanged in both thedry and the wet conditions. In view of water application e$ciency, irrigation period exceedingabout 1* minutes is inadequate
Key words : Micro irrigation, Perforated tube ,Wetted soil volume, Bypass ﬂow, Water application
e$ciency.: efc  hi+BC jk ;<K+    lmn2o+&pq! rstu"vwt x῍ 



.

: Bresler, et al =+31+@\] "!  "#$% &'()*+%, yz! - yz % {|Kefc "#$},! ~&'(,-.)*&/01234! 5 6

}f+ K#3:  ! OP- >?  +7- 89&+-: )* ;<K.$,3+,$.: ,Q,! o2=! >?@ ABC;< =BDE0! FGBC%R YZ  >? [1-\] K,3_

@ H IJKLM$/012! /NAOP1! %&`+abq!  "->?&OP._

QRSTUMR2$.:-.: VWX YZ  >? [1.

GKc "-\] K^#3_ &`+ab: \] "

 ! G ¡A¢£&¤-)*

&w,$uq! ¥¡¦§u.$¨.R2$.:/0.$

Warrick, +31.@ Aefc

cdc

=Philip, +31+ ;=Brandt, et al., +31+ ;Lafolie, et al., +323 ; gR! +33,@ "#$cd12$K.3

© %ª"#$«%QR\]¬%/­&®: ¯ °* O±O±²!±YZ³ ´*0ῌ2/23 µ"¶· 3 ;¸ 3 ¹# : ῌ! ! )*! º»$! ῌ¼%

E+} d 3+ ¼ ¢,**,£

40

ῌ+Fig. +



a¹b^-ºG

»cQR+

Imaginary root zone at the experimental soil proﬁle.



Z[?4E+}> A#zlm     A=~> / Z@ -CD& Z[ E%+} !"

# $% & '+** cm- AB

FG  O  H } /* cm- AB ()*+,- ./!0 ~= , I<JEZ@  K

)*1 23 45

LK32.+ kPa OFG  B #67 8 9 :!;<+* cm B . cm I<JZ@  CD& Z[

=>?@  A&",-B 

=GK 0.1 kPa OICD&

%C D>-E FGHI #Z[ '"  CD ICD& Z[     '" 45  JK 

E DS#$ D   UM!)*+,-!LMN>?"  O (H } & Z[)*N=L

PQR+=S#I$8%$TU&'V WXY8

!0! v O DP

:(JKE MN>D?"Z,    ,+ 

N> '"  O  H }Z[Q F{R1

Z[)\* ])$^+_`aGbc]def

$K¤ TM¥

S ( -¡ ¢+321£E X U¦M'" ,, 

#$§)*+,-^+^ghi,4-jklm'" 0¨ I#© VWX§MN ª

E./0123X+ 4n8op56¨#«¬G­YW®¯Z°

q Ap+ Ap, 8 ,A =- 7r8s jk±[²³´I# VW0 µ + ¶lm9: t=udGv w; Z[Z[dGv xyz{fv<=A|B >61/ cm I#]^YW , #!_ ,* cm ³´VW'" 

0 Z[I#!¸%E`^#·7\!

JK : F ¼,Y )ῌ+Table +
Depth

HorizonTexture

cm
*ῌ+1
+1ῌ.*
.*ῌ/3
/3ῌ10

st+N67

Soil physical properties at experimental ﬁeld

cm cm

Dry bulk
densityg cmg-

Saturated hydraulicconductivity*
cm sg+

Unsaturated hydraulicconductivity at g,.3 kPa
cmg+*41*40*
*40*
*40*

*403
*4*+4*+4*3

340+*g-·,4*+*g+4.+*g-·+4++*g242+*g.·-4-+*g.4++*g.·04++*g.

+4-+*g/-41+*g1/4.+*g1
¸

ῌ,

H»¥

Porosity
-

Ap+
Ap,
,A
,AC

41

L
L
CL
SL

g-

* Geomean·standard deviation  -** cm 






  
 #$%&'( !")*+,-#$%.

/  0 + #$%&'(1! 23456789:;<  / ==>?@; ABC .* cm >C // cm 
DEFG#$%&'(HIJ K
E #$%&'(LGMAB -*cm :NOP/QR CS#$%&'( )*+,-#$%. / T)U$VWXF V(YZ[\G,]^/ _  AB[\ `ab!cFGde de"#$#^/ ;f + AB$
#5 /* cm- ming+ !Khij +** cm- ming+ 

Fig. ,

j k%L &l'mn*+ok% ,¹º

Water retention curves of the surface
soils.

p. Lhrg+ 5(9:GF?G qrst
+** cm-ming+ u0 Lh rg+v w:x!yKk%L

st+N673 + 1! MY z{ +** cm- ming+ deN| }JL s85.L" Y()234~FG*!" 1,*st9 / cm {)*+,-#$%.

5g.3.+kPa J);g..3 kPa 23J)L , *9: Ap+ =;;G{<5!y 01= 3.0+*g- cm sg+  =
x> L = Ap, ; ,A ¡K g..3 kPa +N,#-!

L5 {< ?%>¢@1 01

;ABx23J);G  J)= Ap, 5 +..+*g- ,A 5 2.2+*g. cm

st. J) 23J)stsg+ =A£¤9K 9B : X ¥¦§¨©

J)stABj{?@/4501K

AB Ap+ 4 / mm BC5ª«L w_GABde23 w 9 / cm  )*+,-#$%.

54g..3 kPa Kz5j

5´E9:

_0 , FµDG~FG Ap+ ¶ , ;;Gg32.+ kPa _F- 
-++* mm D%BCx¬_:GF _ Ap, ,A ­®¯ *° ;±²9:>Cm³J

#5!y Hg..3 kPa !yF
#$%.

)*+,-

-!{#5F;5I Ap,,,A >¢7J1 +N,#Lg..3

YZ ¹῎º » 3+ ¼ ,**,

42kPa 





32.+ kPa



ῑ Ap+  *.+* Ap, *.*0 ,A  *.*. cm- cm - UVW +/  Ap+  Ap, 



[\]^

_

x%789: +/ yz

x%{C_`ahvw l |} Ap+ -, 

 !"#$%&'( )*+,-./-&01234ST`ahvw c#def ge`a%BsS _`ah=>ῒ?@%ABC DE  !"#$FGH

B1

'



4IJ%KC 5678 L4MNC

O - %P ./QRST  5678
UVW +* X%YZ[\]^' c#defge`ah

78

i~E lEyz

 ge`a%=C_`ah 78 vw

 56789:;< +,* X%+\@ C%789:

D ῍<YZ Quu6? s%ῌ'_`a%b

%%H' U/I (ijkCB )*J L4MN%oBC QRST O l X 56784I1%ge`a%m. u6ST O / %P QRST 

no&p<qrsS< Utῐ4

1,* Xc#def .a YZ[\( )%ABC1c#d_`a% .* cm ῏EYZ[*23 ( )*23H'ῒ?4I1\]^789:CB< DE%=Cu6%<' lC 0* X% // cm+ kPa y-P Utῐ4n

 c#d῏E ( )* MN~
E'4I <'D%3 MNW '1¡<'D¢E H<£¤c#d_`a% +* cm ῏Ex]^ +/ cm %ABC¥1¦( )*23 4I L§%¨B
f1( )*2w .b ,* cm ῏E.c // cm ©ª23 c#d

 .* cm ῏E.dUtῐ41,* 

X1( )* 23«<
DE%=Cu6¬­  c#def /a %A®'( )*JQRST ¯°YZ[
ῌFig. -

5678 J O ¶·789:4I8¸x[H
Advance of wetting front (numbers in
the lines show minutes after the startof irrigation, dashed lines show theboundary of the horizons).

ῌ.
Fig. .

QRST

U/I

\( )*23 c#d +* cm ῏E


/b

 +2 X%YZ[\]^  / cm

A&±x]^

' +/ cm

lE²E



23 lEyX , `a 56³<'&p%78_`a%vw % ,. X%
 -/ cm %ABC´µJ O+,

&01¦(¶·4I min

Matric potential distributions at several times (mim) during the irrigation (dry condition).

12 : ¤¥stu23( ¼44$9 <% B

ῌ/Fig. />@NB4%Lº*%043

c*m»6º min

Matric potential distributions at several times (mim) during the irrigation (wet condition).



,* cm /c 

 +   I', < !E" +/ cm 

)( 

!"#$%&cm $() c .c $

Y && ,A I ,AC  /3.* cm  /d $'() Ap+ %

I&)qr

9:$" 0* 0

$*+, -0* -$./, kPa 0"123stu"'9 +* cm & 4%56+78&

cm +$(NB$;, % ,AC ${&

0!9:; <=>$9?@ABCD2
 %E FGHIJ9:$; KL%=MNB$OP QR; <S? TU ;%V WXH Y ?@KL$'()#$T
ZH[I

)( \]^_=MNB

9,>@NB#$TZ& `;a#I;b)c - [ 4%KL$'()>@N

B$de<?

  9 , f   +** cm-

min/+ ghi& OPhiTZ&

YIFj

<



,A I ,AC 2%#SV,* cm S? n [IopIFj

 =M

NBOP Ap+ I Ap, qrstu
cm k$

$'()dIve+*

& I|b  Ap,  +1.* cm 2%u&) ,A ${& Ap, I ,A Ib IFj

;b

>@








#& t ¡$1<%

¢%2£Y ¤¥stu$9b)hi%¦§¨2&u'©6(ª2Fjstu%#$ +* cm 

$«

¬

­®HI&) ¦§¨2stu %#$;b-/ cm #$ .* cm ¯+[ hiw  %lm$Z|;};bn >@NBc /b $'()  $%#$  $x(yz{6%f?

& ^_

" !$#b)%

 -/ cm  Ap, "%!

+  %NBI$$'()%#?@Y $'() Ap,&& ,AC %lm ,A 9,f([I  ? n--kI;[I c . / Ap+ I Ap,  %lm Ap, d:f(

$'()  //I~G

Y Ap,  [$&) >@NBOPyz'9?@%

)I&

c +
<*%V Darcy °$x:I&) ±²

³! . ¯+)¢%2 . <%1$9b)A  ¢%I%lmD($9, Ap, &)Fj OP A¢% +! +320 2£YOS? n  #9,2%#$PI,-$£Y[I| .´H . ¡$

& IFj¯+ ) P µz2¶/·I& ix '9 iy

Z|(Y $ =MNBOP Ap, I ,A  .* cm >@A $k;qr2;b

[

 ¸

X Y ·!¢%2Hc0a ) P $'¹ X ·$&)µ q #/0  » 3+ ¼ 3,**,444

ῌῌ0Fig. 0. P 

L

N

Matric potential gradient and axis of
coordinate at area P for a grid system.

 i iix cosqῌῌ11m$ jkl
#m 3F+F4

Fig. 1

Relationship between hydraulic conductivity and matric potential (Lines
indicate van Genuchten’s model).

ῌ

iy sinq   

  ! ῌ"! q #$

  % !  q !&'/01p1{1 ()*+,-./01

F 1m$!   5! 
pp
q tan2+3iyῌix42 ῍q῍῍,,5- q  q p 6% 7 8-9--1m$20.1 kPa ?

ῌ: ;<= , D 1 1m$ jk#m!

 ῍ "5- q ! ῌ ">  &'Y  5-1m$

5- ? . P @ABC 3D +, H+, H,, V+,V,4 ;EFGH I=' J;EF!GKLM Y N

GK X’ N!OP 3D 0 3b44

U

=I

=' _hijkl!no' 
1m$! van Genuchten 3+32*4 "U5+

+  Ap, 1!J=wx.!z{hijkl!a|¡¢6 8£s!D 2, 3 Y

X’ N

X NIEQ! q’, X’ N

 H+}H/, V+}V/ D + Y7 ¤¥/0

! ix’

 

1_7BC ¦hijkl§ix ix cosqR+cr7῎

iy sinqR1 !1,-  q’ ST7U5 ix’ &?

z{hijkl H+ ! ,.* ¨©

GK X’Y L

 3H/4 U5Xª«¬­ 5-

1¥® . P @A7BC

¯\lU56-/0 3H+4 hijkl¬­ IU ? !qGz{hij

V()BC

WX&' 
D + YZ[\]O^_`a= 
 . cd?-:.!Jefb
 gkl¯\lG 3V+4¯\lU51 1. /cm -. 3V,4 !Y  0* ¨©+°_I ¯\lU5-±= hijk

fhijkl! 1m$l¬­²?s®³I ¯\lU5 -/ cm 

U5no  p!EQqGr! * Q-´c 3V/4  1¥®qGpIUst -; Iuv wx.yz{hij

 D 3 µ¶_BC ¤¥1_kl| *}+2*~d  3*},1*~EQ§+chijkl7!Ys7 gf1m$ . cjk

|hijkl

 U5o  3H+, H,4 U5¹º¬­  +,* ¸I

1·²U5 ,* ¸ : ,- #P 4 1>XU

ῌ28&(#)*+



45

cAde hiTU

Fig. 2Matrix ﬂow passing the horizonal and vertical boundaries of the major root zone (drycondition).

Fig. 3Matrix ﬂow passing the horizonal and vertical boundaries of the major root zone (wetcondition).

ῌ38&(#)*+

  Ap+  Ap,

 

"#$% &'(#)*+

H-, H., H/ 
H, !

cAde x`TU/ _`ab klT4m% abno
?1>WX p4,- q V+  V, j.
r1>WXstu v64w%Q x,- ./01234 +/ cm 5678 V+, V,,`TUyz &{('(#V- 9:;<=/0 ,* >?4@A4BC4DE

9 A|RSTU4no+ 9A|4}~% FG78 V., V/ HIDE% JKL/ JKL/0@lT41>WX%QP v

0!56 V/ MN#OPQ 1* >?4



RSTU

4
V1>TU1>WXY3 Z [\ ]9 ^ - _`abcAde/0f/g4 hiTU 123j.3




)*=

 p4RSTU4&{(#)*+

123WX H, stu 6-. 

:;[\/0,- #PQ#yAB» C 3+ ¼ #,**,$46

῍ῌ,
Table ,

8Bn)¸@¹Hirizontal, vertical and total amount of water lost beyond the major zone

Initial moisture
condition

Applied
water
cm-

HI

VI

cm

cm

1,5***
1,5***

+
+52/,

+5/*2
052++

Dry
Wet

-

VIῌHI

S

-

Pm

cm

cm

05/21
35*.,

0-53*.
/.5,3/-+5/3+.

Pm/Applied
water

-

*.23
*.1/

HI ; Horizonal inﬁltration, VI ; Vertical inﬁltration, S ; Storage water, Pm ; Bypass ﬂow

 

  !" #+33.$ %& '()*+,-0.

/ 123' 456 78 3

29:;<()=>?@A38B()
*+,-C

.

IC

0/JK,L +* cm %

DE'F6 G ., /

9H +*

B

 MN-OPQCR/AS 4D3T<
K,L;<F ,* cm BUD123'V/6 ()*+,-C 0DE'78()*+,-F

0DE'/W

16 R;<XYZ%'F[\]'()
=>^/126 ;<_/12K,L/`]'aFb+* cm6 K,L/`]'a
Zb-/ cm6

ῌῌ+*Fig. +*

ZF .* cm c d14DCe*L!"fg] :AMN-OP
Q#hF$i%2 9 #G /b$6

%jkl

%/0º¦#h

Cumulative water storage of the major
root zone during the irrigation (solidline shows cumulative amount ofapplied water).

m'5Ce*L!l&]''(FE'V/6 n)CopqL!/e*L!*DE'/ 0/ MN-OPQc9

1  'jkCr+,5jk#12(c2i e*L!

6 /st

'Ci'V/F:;DE'V/6 ea u-l&]''(FE' Z6 e*L! 'u*L! i6 XY/12i-vm6 V jkwxD.1

. , ῌta6 e*L! 'n)6

QySzEpzPvzPhzPm

]' g1 ¡¢£¤DCῌ

VVD6 Q ;  #cm-$6 S ;%/0 #cm-$6¥<¦aC + cm- /=1 §AS

Ep ; {"| #cm-$6 P ; n) #cm-$ D6 1m}

  0/Jt;n>Fa 9

 v, h, m C~%%taopqL!6 J?¨123 4 32d1

aopqL!

ta/an)@C6 ¥<¦e*L! 'n).

]

1,*

iCw/ 9DE' {"| '

I  ¦  D ( ) 0   .   1 2 ¡ ¢ 0 F+,/3+ /A96 ¡¢0Ftan>F?¨]

CFA 6 ,QQ 9.2341'/3:©ªAS 6 1,*

23'V/6 51 6]'n)

*L! 'n)C¡¢05 23῍6 (:opqL!C Darcy r:/16 )05D 1/῍ J« 6 iqL726 826]'Fe*L!/12!¯1qL n)626]'qB 'e'¬/­®

G +* 8B/0#hg] 4°±

Li 672C82F

 1*+,.** cm,62F +,0** cm, DE' 6 /0CAS ¡¢0C 1*²³6 ¡¢ῌ()0/J´v

CµZ²³J¶·´v1

hi : NBC-O5+9t MD 

   !"#$ % 

 +** cm- min&+

'

(

47

%%) (  NBC-OVW0=>@P M0=

G!OH1L"#yOk NBC-'(  VWI)*+,-./0123  

% b 59t\JK ZM&

456789-:;<+)LOk ;byOk')*J=>;?0:;%  @A BCDE;?%
kPaG

 

ΐ

 F&.3.+

 F&..3 kPaG HI

<)J

LO A <J MONOO Ap

KLM)NBC-OPQRῐ ῕ ῔ ῑ=>;?0O 1,* A)ST "# UO !VW QRX./0
ῒ:; 1* A))Y)J

Brandt, A., E. Bresler, N. Diner, I. Ben-Asher, J. Heller;and D. Goldberg. (+31+) : Inﬁltration from a trick-? 1*  =>;?0  le source, +. Mathematical models. Soil Sci. Soc.

M Z [

\]^

Am. Proc. -/ : 01/ῌ02,.

_`a b VW) X./0

Bresler, E., J. Heller, N. Diner, I. Ben-Asher, A. Brandt

!0cde VW)BC-b

and D. Goldberg. (+31+) : Inﬁltration from a trick-"f +* cm # )J X./02$g

le source, ,. Experimental data and theoreticalY) 1* hcPei%f23j)J

P % )NBC-O

Ok'VW BC-

predictions. Soil Sci. Soc. Am. Proc. -/ : 02-ῌ023.
Lafolie, F., R. Guennelon and M. Th. van Genuchten.

l&RmOn

(+323) : Analysis of water ﬂow under trickle irri- 0 X./0o'p'l(qp)*

gation. +. Theory and numerical solution. Soil

J A )r+QR 0s pe *+,-[,3-

 .U# '5+9t /034?% b  QRYupv)J

Sci. Soc. Am. J. /- : +-+*ῌ+-+2.

>  F+321G : P X QMNR
ST U  // F3G : ,3ῌ-/¡HVWῌ¢£XY F+320G : ,¤¥^¦+Z+§¨© ª«¬­ -1ῌ-3¡.ῌ ῎ ῍ ῏U[®¯°\±]²³B F+33.G : Z±^´µMZwx)NBC-OP5+³¶ 5+9t  Uµ_§·

9t OkVW0=  Oy1

Philip, J. R. (+31+) : General theorem on steady in- wxVW QR0i

ﬁltration from surface sources with application%f2pz{s p2  "f)

to point and line sources. Soil Sci. Soc. Am. Proc.

34c|-}BC-b5?6

-/ : 201ῌ21+.

QRO*  wxVW 7~p
8f90s :<b? ,Z Ap+

Ap, ;;0=> <;0;O="fs`=aῌ¸b"ῌ>VW F+33,G : 0ccqMDῌJE*dT¹e& M&+ 00 : -3ῌ./¡

van Genuchten, M. Th (+32*) : A closed-form equa-./0b3Oy1  % tion for predicting the hydraulic conductivity of4b  BC-Di%2[>?
P )QR @c|AB[,3  A Darcy C4
M=D

P*+,-[,3O

<  UEb F VW ./0
J

!b?



 1* A))Y)unsaturated soils. Soil Sci. Soc. Am. J. .. : 23,ῌ232¡
Warrick, A. W. (+31.) : Time dependent linearized inﬁltration, +. Point sources. Soil Sci. Soc. Am. Proc.
-2 : -2-ῌ-20.
º»f¼g : ,**+ f 1 ¼ ,- gº+f¼g : ,**, f / ¼ +0 g
J. Jpn. Soc. Soil Phys.
7C
No. 3+, p. .3 /1 ,**,



 *ῌ**ῌ

**E#ects of Drying on Bacterial Activity and Iron Formationin Acid Sulfate Soils
Kaoru UENO*, Tadashi ADACHI** and Hajime NARIOKA*** The Graduate School of Natural Science and Technology, Okayama University,-ῌ+ῌ+ Tsushima-naka, Okayama 1**ῌ2/-*, Japan** Faculty of Environmental Science and Technology, Okayama University,-ῌ+ῌ+ Tsushima-naka, Okayama 1**ῌ2/-*, Japan
Abstract
In acid sulfate soils, the heavy acidity is caused by the oxidation of sulfate, mainly pyrite (FeS,).
In the primal acidify stage chemical and bacterial acidify work together.

These bacteria(Thiobacillus ferrooxidans, Thiobacillus thiooxidans) have a huge role as a catalyst.
This studies were examined the e#ects of drying on bacterial acidiﬁcation, mainly on
Thiobacillus ferrooxidans, and the formation of iron in the soil by the incubate experimentation.
Five water content stages were set (+.-*
for water adjustment.

*.,/ kg/kg) by drying process in the incubator at -*After the treatment, these samples were contained in the each bottles andstarted to culture at -*Thiobacillus ferrooxidans propagated rapidly in the water content of Liquid Limit (LL)

Plastic

Limit (PL). Near the water content of PL, the propagation of the bacteria became slow, and they
became decline near by the water content of Shrinkage Limit (SL).
Amorphousfreeiron increased at the primal of acidiﬁcation and changed for crystallized
freeiron. Around SL, the water content that the soil pH was stable, the propagation of thebacteria became slow, and the formation of iron became stable. In the range of water content +.***.1* kg/kg (LLPL), the samples acidiﬁed strongly

Key words : acid sulfate soils, water content, microorganisms, pH, iron+      !"#$,**+?G ]^M@5_`1 W27M@5UabaV 8[\ +320 ; cde +33*? fg hi
jklming @C3@m2ogpqP)%&'()' *+,-./0123456

8r +302 ; e +33,?G s tuk)hi

7 89':;<=<> : FeS,?

vwIJ1 pF- his1xyhz{1@5 3@2

''AB@C'()DEC F)G H@5IJ

W27M(@5 9|1F} ~yhz{15L

 K5LMNOP)IJ'Q@5RST UVH'

M@5 9|'(:) 8e +33,?G tu

1NOP)W27M(IJk:@ 2)k (M@C3@m

XYZH) 8[\* bLbLL 1**ῌ2/-* 0 -ῌ+ῌ+** bLL 1**ῌ2/-* 0 -ῌ+ῌ+ : @C3@m hi,- W27 pH Q  3+ ¼ &,**,'

50





ῑῌ+

5/ 
& 8912=4@A 5( +2/>,+*cm'           

Table +  !  !" "##$$%% &Thiobacillus ferrooxidans' &' ()*+,

% -.(/

,0)* + % & 12 +321' 3
, 

-.4

,ῌ ῐ῔῍῏῎ῒΐ
5/067 8912:3;<=4 &5( +2/>,+* cm' 564 7?89:;<4@A
&=ῐ+'



4 B C>D?,E FGH

@ .*῍ ,HIJKLAB

MB

2 , mm OC!P. NM ;<N

4 D4,EF4G,QRHS ?T Q+' 9g &Mgῌm-','LZH#M &kgῌkg'
\] LL &kgῌkg'P\] PL &kgῌkg'
QR\] SL &kgῌkg'
Phz Ip@³g A-'
pH &H, O ; + : /'pH &H, O,'
EC &+ : / ; mSῌcm'£qLHG &wt.῍'.'
+'



,'

#J,,LZH#M &+.-,/ kgῌkg' Y=N2
[OP\] &PL' QR\]

SiC &@ .*῍'
,4/2
+4-,
+4/3
*4/0
*4-,
+*,4..
14/3
04,/
,4*/
.4.+
.433

´µª¶k±k{ &·t'¸¹º¶k±k{-'
A»Ipῌ , mm Y=@H &῍'.'  )G{ &¡a +30+'

IUNV##J,,WA4X Y=K,PMN

Fundamental physical and chemical
properties of sample soils(in subsoils Polder-Nakaumi, Shimane,depth ; +2/>,+* cm)&SL' HTH#MS^ -*_ `aST # b

V# / Uc &H#M +.-*, +.**, *.1*, *./*, *.,/ kgῌkg : Y

g &v#`  { : a +33.' b2 A

X +.-* kg ῌ kg <>% &Fed : L%

efL

W +./ cm g

=d'

V)4



Feo &X' 'hijklLJ5/"A% &Feo : J %'

Q)XmT nopqYZ4 [WA,&T o e¡ +33-' ,¢X)4 BT

r/\s PL  ttu#J, &H#M

£qL>¤ -.%

*.2* kgῌkg ]v' N2    /%&' #J,"%3,,¥4/  ^_ `3aXwxb/

" 5/%% &' pH  +./>../

WQ BT,yc lz{|ld}qW + cm ef ,~4YZg b w,hi4xWQ,jh4¦q§¤ &' e{ &' |% &' ¨r{©ª«k3,¬&y2 +33-' ­Thiobacillus ferrooxidans®

B #$$,V)4 eKk

Vv  4

[4ls#9m &kTno ' 4 -*_ `aSBB

Tpq4 #V)XJ, H#M

ῌ A% :  =d ῍ Y¯% &}+.-* +.** kgῌkg <jklLJ *.1* kgῌkg <Y=

wJ

M wrWx />2 mm M eKk ,sῌt u 4 v4wGRPM%% &Thiobacillus ferrooxidans'  Fe
Fe-

B

,

,

 ATP ,  +   &x y 2°±Lt²k±L>A'
῍ A% :   Fe, Fe- Fe &OH',
Fe &OH'- "%G῎#_ %{ :    Fe,῏ ` |%ῌ}% :  
Fe &OH',%%z &MPN { :  +33,' |G

D{ : q) +33.' #_ %{~Fe-G #%H +330' !",-.   pH %%"}%~g &pH-.*, ,./Mῐ` M!4%3,,Y= Fe, G " Fe &OH'-

Fe- 

<D : 8¦V 9hYj¼ q?EA+£¤

51- 
 pH 

-+  





   !
 "  pH #$ %ῌ+ &pH  "

 +.-* kg ῌ kg '() *.,/ kg ῌ kg '*+ 0 () . ,-

 ./"kg ῌ kg '() *.1* kg ῌ kg '01/- +.**

2  #$ +.-* kgῌkg '() *./* kgῌkg '34567 *./* kgῌkg '() *.,/ kgῌkg '01/58 ! pH () " +.** kg ῌ kg '() *.1*kgῌkg '9:;<=+

>?6+.@A)= <) ! >?#$ 4
!.()

B#4CD:;*+ >?6+.E<=, +/ F+  #$01
34G3(H!.() -*I J B#4C K*+.@A)= LMNOῌ+Fig. +/PQ)= -*I RSTU>?6+V W



Y­+"

 pH #$

Changes in water content, pH and thenumber of bacteria (live) in the periodof water adjustment.

 X Y7 V .VZ[W
V.0\]^ _`a  bcd +.
E1+ -*I RSTT >?Ve*+. `fg + cm 6HD
B#h4C*+!.() Oijk34

B#h  V *+u6+ Fe-

9*+

B#^3

451u!. 36;  .  pH  3 -.@ACl V d bmVfg Oj7 6+ ¡*+6=

3!"#$*+no3.%&<= TU

j7D\7¢£¤ .

>?67 VZ[d bW`A+ ¥O _+302a  8¦V 9 b!.j7



B##pq9'2(

 S §\0:6=; /!.

)1+*rsV+t,&  < S 2. ¨©uno.@A9 0*+ =ª P/ !

"  +.** kgῌkg () *.1* kgῌkg cB# 4v)= !Vwxyz[N>(){>37 `+cZ[|} 4A

 01/«¬*+. §\ _>\ \ a ¢?­)=+!. & -,  

u.~-1+ , "  *./* kgῌkg () *.,/-®,®+kg ῌ kg B#5 Z[|}.3@A pH  %ῌ, &  ¯ 'pH/ V  6+V >? _{

/a DB#. 0<3(H!.

 - 

& +

*.1* kgῌkg ' . ´Bµ C .7 0 ´B  !jk B#4C/D \-("  pH ° ±u3)²³

CO¶ 

0 ´B B#4Cl u

 *./* kgῌkg O6H _%ῌ1a !' · 9 V >?6= n  !=V¸/.3Hu B#h V1Y 2>?-j7Vl  V¹º4»/n()ῌ\ c*+!.j7=.@A *./* kgῌkg 'Yj¼ *.,/ kgῌkg '?@ » 3+ ¼ ,**,

52

῎1 

.eF0f#) +,-. +.-*g*.1* kgῌ pH  !"#$%& kg hi>(K'Ejk9 lhi>($'()Em>(nop#)-*,*, +,-.

-*,*- q,-.rst+,-.$uv+,-./0123045$6

῎- 789) +,-.1: Fed $ Feo ;<q,-. Feo E /0 ῎- w 89)q,-. x2yz<{ 2yz<k!

=> ?@AB.08> Fed CDE|D9E08>nop#) }+,-$~uFGHI$%&'(JKL ) MNO ῎. 89suvp6 q,-

PQRS. Fed  TQUVWXY"XZ[.j+,-[/p(+,-"/.\]!^6_D$%&'() 9#
CDE`a0bcd? Fed E$9+,-

9($&()}s!q,-rst+,-./s! $!#$%&)ῌ hi"A +.-*g*.1* kgῌkg<+,-.k p( *.1* kg ῌ kg o"#jk9r6 q,-.1:{ +,-q,- [/ ) QQR0y$>(..33ῌ =῎+  hi#rst.s( s6 /9¡() +,-.¢$K<p(QQRjk
9¡ ?@As6l' Fe,£m p(¤'0.

9 Fe-£ /l¥ '?@A S $¦§9 l*Fe,£ m9¨© Darrell, +32, $%&')
῍ hiªf>($QQR_«l' ?

@ pH/g. !() 2.
 Fe,£ ¬ Fe-£ $9­®9¬> !6 '¹Hrº( pH /¯+,9 °?@±²!³<p(M´Fig. ,

Changes in pH in the culture period.

µQR KFe- SO., OH0 ¬¶·¸QR a῎FeO

Fig. -

Changes in crystallized-free-iron and amorphous-free-iron as drying (in the culture period).

ῌῌ,

ῌῌ-

his(+,-rstq,-./

¹H

"# : -¢-»LMNO¼¢BPQ $A 9:

ῌῌ.
Fig. .

ῌῌ/?¸¹

Relation between crystallized-free-ironand amorphous-free-iron.

OH  

  !z !" #$%opq(mnFig. / Changes in water-changeable Fe ion
in the culture period.

 P  rῌ0 & =
< ?<



Bº

53

+.-*, +.** kgῌkg

6 *.1* kgῌkg

6&6  &#& , }6 {& '()(*+ ,- . /0

 . `&8?= *.,/ kgῌkg&1 -234 pH- 5678 pH+  { 8?= *./* kgῌkg&

9:$;  #$<=>?@AU < , }6 .  ¡{=B CD6&EFGH(*IJK6 - 

Uu%v68?= LM-¢ /0%LMNOBPQLMRS T ?U=%VWX(*

6& Fe-£ &2$;U- ¤? ¥ =Y Z PY[\X(* aῌFe, O-

$; > ¦%v6?@A`;]  ,**+ ^?U_`;BY abcGde

fg6%^?Ihi% < {6u< kv&wx

t{z

|Qu}

kgῌkg BPQ +.-* kgῌkg

 +.-* kgῌkg*.1* kgῌkg st*.1* kgῌyzu~ +.**6& 

& 2 6

%v6

B% wx yz6u(mn< l?,  >
pH/.0 6&6=<=>?@A`;v&8v  + mgῌg NL
kgῌkg

~

 +.-*, +.** kgῌkg

?u

6&w

 ; *.1* kgῌkg st 6&w ;t 6&v< ~  *./* kgῌkg&?< yz6vu< 2 6%

«¬% *./*

6&?< vu ^;& * `pH  . st6Y l­(mnPY78

>?@A wx 6& ®W¯v°{6

~Y ^  ?@A`; ^{%&6 } opq(mn& P 
?,§ P  rῌ0 & NO=+.**, +.-* kgῌkg

yz6¨© ;BY w ;k;ª;



a

%vIh{ & pH %> %vP BPQ,§ rῌ 6&u%~  ^;& ?< wx -j,j. kl(mn?

opq(mn rῌ/ & ?< kg st
0 & u­ < LM±6& - (mn²<%^?Ihi% & ab(mn³I´&µ¶ ^PYU=%v6BY
rῌ- f·PYU=<$;ºῑ » 3+ ¼ a,**,b

54

ῌῌ1

῏

!

Fig. 1 Changes in the number of bacteria(live) in the culture period.

῍\rstS῍GuvwXxy%z&- +.-*'+.** kgῌkg (*&{|}6{~- *.1* kgῌkg*&|}6~K_8ῌ`1TU
ῌῌ0῏h¸

- ¹¸

!

Fig. 0 Changes in ferrous and ferric ironin the culture period.

1B- {FB&~TUG
*=-  *t6%
῎

PL wXiiBLM a*./* kgῌkg (b *&-TU&0-  E0uv*&1B- :;@A"%
- , /



῏

TU1,- GS

- , / +

῏SL ./LM a*.,/ kgῌkg (b *&- 

!

"#ῐ1

i"ῐ%-  E0$%  & +.-*'*.1* kgῌkg ()*+Gw- LM&=,- *./* kgῌkg (./*&01 +.-* kgῌkg (&,"^῎f*F]^6S *

234 * 456789% +.**, *.1* kg ῌ kg

&- +.-*'*.1* kgῌkg (*LTU- *./* kgῌkg (.

(*&- :;234 * 456 +', 4<=- >

/*& ¡¢FB&ῒ£~6y?- 7 89%

*./*kgῌkg (*&7 819¤*F¥¦S G§Mῒ£~¨

&1,- :;@A<B *.,/ kgῌkg (&C%DE0©ª%xU=,"^\BG1@AF «- ( a+.**'*.1* kgῌkg (b ¬­®*:;¯6S a#ῐ1b - GS

GHI6- JK +.-*'*.1* kgῌkg LM*N%OPFQR*=
GS&- TUVWFX- ./YZ
[\B]^ῌ&°±3²῏- , / ,

TUK_8ῌ`1 LL'PL L

M a+.-*'*.1* kgῌkg (b *&g*Fhcdef

efijklmnopq῎1 f

"ῐ"^<HI]^ pH pH VW"#ῐ2 $% ³
(B\- B pH %%-

+B@AF

"´µ¶·81 pH

 : "@$"45 h W@&XY! aFUAB

ῌῌ2

f&8 pH 



55

9Z

Fig. 2 Relation between pH and the number ofbacteria (live) in the culture period.



ῌῌ3f&845

!"#L



9Z

Fig. 3 Relation between the ratio of ironoxidation of soil and the number ofbacteria (live) in the culture period.

 pH 
   !"#

$%"#

&'(

)*+, -./ +320 ; 012 +33*3 4567&8 pH !"# pH9(:;,(<2= 45 >#?@

AB45CDEFGHIJK!"#

LMNO)PQQR STU2
-V,V/V-

45CD! "#W@&XY!"#
 9Z!45 "#[\]^ pH_#X`aF_# -bc2d +3323 ( pH ef gh)ijkl4
Fe,mno Fe-m

45&8

EF

 !"#

X

pq Oqr'*s !"#W@Mtulv( 45 wx! -Fe -OH3,  Fe,m
-Fe -OH3-  Fe-m

yq3

yq3 zx!

{|q _#M45 !

"#L -}zx!{|q~ῌ-}wx!{|q~m}zx!{|q~3 +**ῌ3 ( 9ZM-ῌ33

ῌ3 X 45!"#L +.-*, +.** kgῌkgῌῌ+*f&8 pH 45

!"#L

9Z

Fig. +* Relation between pH and the ratio of
iron oxidation of soil in the culture
period.

 i  *.1* kgῌkg j iCD 'Ss{CpH   i{C!"#.(!"#L<(&isABTU2 45 !"#` 45 !"#!"#L 

{C +.-*+.** kgῌkg  *.1* kgῌ9I9Z *.1*kgῌkg 9ZS` *./* kgῌkg  )

W S ῌ3 kg 

X* !"#L v2

 9Z +.-*, +.**, *.,/ kgῌkg  9`i *.1* kgῌkg 

.X)

S [ p 3+ ¼ _,**,`

56

9:F/W4 ;X/YZ[ <:;, \]^ _LL` %&<]^ _PL`BaP3Q4', , 569:
7=30, PL B'9:>?@&, bc]^
_SL` B3+ 56"#d*YA

3+  56 7, *.1*kgῌkg? _PL /0.ee(#`, F/W@A'(#+ 56f#9:,( SL Bg'B#hCDd
ijklE$m0, <%n@'F#hGH'oI<.pq
#HM4 r#, st uvFJw,  xy z'{|}|~K8
N   pH @&I, .3#
Fe,, Fe-, Fe _OH`,, Fe _OH`- KLzMN
῔ῌ++



9, pH/ %&'|  RF9I

Fig. ++ Changes in the ironῌoxidize-index per
bacteria (live) in the culture period.

AFJ60, :z I)*[ LzMN:zMNRF I, 
569:@&, pH '+ g, pH @&Dῌ+*   _O +.**>*.1*kgῌkg` '



3 569:>?@&g'  pH   pH  
$ pH. %&'!"#(#)*+,- pH './0 -#Pw,  56Qe, CDFJij r#R+I, pH 1 2 34 '3ΐ$, -56 78#
9:;

ῒ

1SI0, ITUV<',  6 '=6
0

I SL B  ῌ++  +.-*>*./* kgῌ_WXY6Z`, 2uv[2D

[2\2 ]K¡¢£Gg

7($, *.,/

I g, kZ¤¥0^¦§X_¨DX`6kgῌkg ?' ,2 B'C$!", AZa©ª«b3¬IcCg ­®-6 7D.(#:;3+ ¬de%¯gI

kg ?', @A'6

, '# ,  ῕

E 2  ?!'CFG, *.,/k gῌkg ?'56"#)*+H$I, fgh«ῌi1°jῌxῑkj _+33,` : 

?FJ%K:;&#'LHM$# 5±²l`8S6"#)*(N, ! )#*+

³, +0, : 23ῌ30´

0, , 56 7-I./O0*+#M

mU n _+330` :  µ¶2, pp. /0ῌ1., ·¸¹º, o»´Darrell Kirk Nordstrom, et al.,(+32,) : Acid Sulfate.ῌ ῍ ῐ ῏ ῎Weathering, SSSA Special Publication Number

12, P3Q4/0567R 8S -*T UVI/0, 

Q4, X256

+*, pp.-1ῌ/0, Soil Science Society of America,
Wisconsin.

() : 1, 15¶·?¤¸¹,­3®7º24»¼

 +33, : 



pp. -,3ῌ--2   ῌῌ
+332 : 

bcde ,**+ : st pp. ,*0u,*3 n fvS"! fvῌ

. ! pp. ++0ῌ+,0 "!#$%& '()57

wgxyῌ z{ ῌ |

 ῌ }~ ῌ 

+33* : BCD1,6247ῌ.891:;  <= 0+ + .,ῌ.1

+320 : *+,-./.012341,

SῌTd +322 : 8.0ῌ@

15+67ῌ.89:; <= /1 -

17$$&6 ! [a ,2 , -*ῌ-1,/,ῌ,/0

(> +30+ : ?1@A234BCDEF
1,.89GH <= -, 0 ,10ῌ,13(> +302 : F1,.8912IJKLM <= -3 , ++0ῌ+,*
N OP +33- :. PQR pp. ,,ῌ-,S"! E

TῌUVWX +321 : YZ[\1,]^ῌh

ῌ wgxy ῌ  ῌ z{ ῌ '"ῌ|ῌ}~ +323 : E¡BCD¢£ῌ1?¤67ῌ ¥1:;¦§¨#
<= 0* , +/+ῌ+/0$©ª ῌ «%e +33- : Thiobacillus ferro-ox-

idans 6 T. thiooxidans &_15234` [a ,1 - +/-ῌ+0+
bcdeῌfgbῌ +320 : 

ijkjlmD 0+ n opqr ¬­3®¯H°±6A² +*3 //-ῌ//1
³´¨µN : ,**, ¨ + µ . N³'¨µN : ,**, ¨ 1 µ . N῎
J. Jpn. Soc. Soil Phys.
TU)VW&
No. 3+, p. /3 ῌ,**,῍
ῌῌῌ
 
,**+

A/
,0/  +,2** 
 !"#$%&'"#&()+, h%+- a*+,-./012)01+,-34)5&67

῍ ,)'i

8'9:);7< ,+ =&>?< @)A&?

,+ ,)

#BCD)$%)EF)GHI'H#J

,, TUK)$% ?)L%34)!";#',- 

?#J #$%M&)E'< (NOPQ)9?%F))C*+;7< ,-R34./,. j῎ )%4Y

S0C67'T4J 3< U12VW Xῌ34

-+ $%)

Y)5Z6W[7)\H]'H^@)8C;7<-, h%)

_)`Y ?a)! < b9C:c< d;ef -- )9))!

#J-. .#wxk3< Dgh<=ῌijkῌ>L5?H^
34< l@)A=Qῌ(NOPQ2 HA&-/ )lgc4#.`)u)mn' < B #J ./S0< '@m./S0nCD

C() CR;#]';#J lo< ,

EFHGoC;7< ]]5pqr S0.

)'i C 9¡¢< p

/H3G& BHIH3GS0CJKJ ,)%4Y 'H7K C() '`£qLD34)sM)t2NCu< Clr]Hu;¤`J 3< C() C

F)OH67PcC-R34:94

R)¡¥'Hf #']¤ )mnCc4#J

J

"HBY<

:s?¦C§;#3)¨< 5pqῌIH3GS0CQH#A=Qῌ(B;#'©B#J )01.7:*&ª+«

NOPQ)cH@Dv)wxW%Ry2 z{O #«¬Ctc6#J l< ,, )TU<

|}"#]'&~*SJ '@< TUVW3

-. .#wxk < ;­¤'TU.

4c XYG#Z[;#J \]< IH3G

/wx8®&¯f #2'f  g34`.#7)^_`)ab< _.#Qc¤] '°±4< uCvG< O&w tc:c<

 5< 5pqS0.#TUu) d< )K -/ )l x9²f #J%ab./PWH^)e) %H^wxW%Ry"z{O)|}Cf43 #J)g< )'7;#Jῌ C()
++ $%

3<)mn34c < ^]34tc 9#3t2)y;7< 8³z);#']¤34{_]t´:o±#Z[;#J ¡¥:|µ;7< TU
VW¶ )}~lt&:9J·,¸ ¹º¶Dvwx»¶{¼

῏

῎

῏
J. Jpn. Soc. Soil Phys.
WDNo. 3+, p. 0* ῌ,**,῍


,**,   ,,/** 
A /  +,.  ISBN.ῌ11,,ῌ.*-,ῌ,+33+  0

+/  

^1_2 GCD'()*!"#+ #1 C)` /abῌ ῍ #+),-. /Lahar ; 0, 3 8"& cd,- /$%&'()*1

2 /340

0
0" 562ῌ

789:;<=>? @?' A !

- efKI#& /0"BCD6E'()* ,-.

.#F G$%# H6& EI8JKL'6+ E
M' ()G  N*#& O PQ)+
R'()*

ghi#j /

0/ &]) /= g /00 k)MN /l0&  ,-8)S' ./1T

1 KI(dA@l 1@l S)MNUVWXY:=:Z[0U\KQ6"* T 1

 /ῌl0

2 CAJ3KIT]'EK6L^ ,4'H2 $%  GA m'n) /op0

11'()* 6_6I 33 #A 1eN /qrsῌY`a,-.

bc 567U%PA#")KI'()* dTe(fLg6"3h"U]6"i8U?IA#")
9:;<=U()*:¡.0+*  ¢t\ /uvw£¤0##j bfA#" >?k @lU M12 /¥x y

90 U JICA z{¦1#§¨V:y©|Aª

A1BmACD@k9n:16o#kDMpq1

W« ¬}#")1H o* 

6oL A E#@ AF rsL,-.&

GA tGL#")1E "u"u6vw
KI;HPA#")*$A xI# ,-. yJ KL zSM
8' K6LMNU"# MN

#~+­=2®1

]  ++ h°

#f1S* ANU@k{|}1@lk ~}I"1 ## 1 

¯~ g#

1§¨V:eo#" ±Problems, Challenges and Opportunities² 1"DU H6p*= 6o11'()*³K´Eµ $

o#"T"1U

OPPUzfo#")16UQ-vw "(o* K ^¶· ¸A#"#F¹U

#RIA#")* MNUNST'(L7U

Aº #fo* A'()1U / V<'H)*

' 6"U  ,-.1,-. @l MNAAW N

X6 /=1E)U 12IU g /=1YZ

[NU\8)='(L o+L1^

Q ]c '(o*»X ³K U 6o#"E·Q'()* TU . ³E
I6KoT*   e'JS#()'
&U¸KoCD6U8)*¼9rl /¥x y90

 !
J. Jpn. Soc. Soil Phys.
v
No. 3+, p. 0+0, ,**,

+  +.  +  -   : ,**,  2  1   +, : //῏+- : ,*  ,  -  

ῌ3,ῌ3-  < /wxU$#,  ]56{ :  : :  ῌ ῎ ῌ  ῌ |+,}

<yRz
/|}

23

ῌῌ ῌ!ῌ"#ῌῌ῍ $%. ~Yfu

&%ῌ' ()*ῌ+,- -ῌ~>x Rz~&% :  ./&ῌ0 &(+,NU$#,. fu/|}23

1 :
+

ῌ῎./>x 3+ /Y|,-./fu

0123



:  

v Y-w

D  56 :22!"#$

3 3 4

+ 56 ++  3, CD EF!+,&%A4 ῌL

789 %: ῌ;<9 =&' !2()*#+,-./>?0123,, 4@ A4 5B!"#$ 56 ,+ LP

6CD EF!+,&%A47 (8-!9:;$ <    ,**,. ,῏,**,. 3

B /  9 = >?!5G+,-./>?0123-  .. @ ABCDEF!"#$ῌ ῌ

ῌGHI/JK >?!>?0123

 

 ~ I5(8  =&I++  ,-   =HILJZ

GHI :  IKM.NOPQ R 

LMSR
῍ LT = .U$JK NV.WO!P,-.

/>?0123+o ¡, 

B +2 

QXY9 PZ : [Rῌ

\]

NOx

j' 

8S^9 TUῌ_VWZ : XW
CO, . O,-

MoldrupY`Z!+,-.

9 aHbcbd e fBIH

g : hij

NOklm[\G!+,῏0]^ 

9 PZ : W_NOnopg

O!+,-.
/ `G WOY
῎ q + r.ab! COsH.tMc

¡

¢<£¦

¢Y§¤¨¥¦¢S©§ª

¨ ¦Y
¢©«

-.
.

¢£ ῌ ¤¥pB
sH

I!+,-.
, ZBsH¡=ZBsHª¢«¬­8

7<¬z®Y¥&%¯­ ®

=&¯9Z°®±²³°±°±

¥'´±



fu :

 ³

0Z+  gv&h iῌ-wµ< ¶ῌj>xyk!gv//Y01,-./fu·῍X

(de+,-./>?0123

0123
ῌ!./&>x zlm{ iῌ-w!"#$no/|}23,  +3 ~pqrsῌ῍$%&>x/ t!qrCu(sU

2-./fu0123

²¡¡i' ¸´' ¹

iPQ'µ­ῌ¦­8

¶·³¡¸º + »¹º»bO¼¼»62-  ,**,. 3. +* 



: .-.



: ,*



: +* 

: /. 



:

.

  : /,,

63   
,  

 & ! . " pH '( #$%#$%&

)4()0NO,A  -;.  pH P@
QRST%% 0*(, 4NO#$% pH -;.  , UV#$%5W+1 ,X%8Y  ZR#[-.\/0] *+ ,-./0, ?  M-.\=^Y ZR#[1 23456750,8./

1 #$%_2`Ja3,A  

 6  1 9

pH

!b41 5c6d!D( e7

: .;2  pH :'(<=>,f 4NO ghi# jkl mnop"

<n8qr < s(,
t 2uv 9:-; j<=(n(nw>n./mrx? @ 0,A  B!
C

<

 D(81#$%8E?FGH &'IJ=KL M


y?z{@

2uvo

o
C o
D?y
o y
2y
o 


|ῌ
} j<~(n(nw>nABmn./mr - j<~>(n(nwr῍E j<~(n(nw>nABmn./mr FG j<~(n(nw>nABmn./mrE j<~(n(nw>nABmn./mrH
I j<~>(n>nJr jKL>Mru v
NO PQ j(n>nJruv  j(n>nJr
H  j(n>nJr
H RS jTU(nV(nJr
ATWX jY (n>nJr
ZUW[' j\Uq]^>¡_./¢{r£T¤W` j\Uq]^>¡_./¢{r¥ a¦ j(n>nJr§b j(n>nJr
9: - j<=(n>nJr  3+  jovcdr ,**,  1 ¨ +/ [eq   ©++-ῌ20/1 <~f ~ªgA +ῌ+ῌ+<~(n(nw >nABmn./mAῌ«¬nh­ «¬ijn./®k
FAX *-ῌ/2.+ῌ2+1+.
l *-ῌ/2.+ῌ/-/+, /-1.
Eomail : sp-staff¯soil.en.a.u-tokyo.ac.jp
URL : http : //soil.en.a.u-tokyo.ac.jp/jssp/°q± mW²°q ³´nqno rs |ῌ }op ,.*101-

 t µ¶·¸o¹©++0ῌ**++ <~fºuªvw» 1¼+,¼+0  
A/ῌ,,2

 ,**,
3 
ISBN.-2.,/-*--0-X C-*0+
ῌ +/ ῌ +,2**ῌ 12   -,0**       /

  !" #$%&%'()*!$ !+*,

$F +3/1

 vDH ./

VAL) w;*A0X YZ 0xy z[B(KQ\(A{]/45:;"I$

,3 /01 |^_/*'O"}~(A`!

2345 6 7 /"89:; <=!>"'I&2A )I/aIL$'bI

6#?7 @'A$B08C:;*!$ /"I*, 45  ,*-. +332/

c$/

DE$B0F GEH;$?=/%!IJK d :;$@ #e !$&LMAF(ID'F'N!"I

& f/L$';*,

*, *'OH;$F (( d :;"DH ,/=/ 6)P* +*QR7 2S,T45@$H!$g')IF #

 -.45 3(K/0'!"I*,h:*!$ w-i 

Aj(kl!  mn-(K@Q($/EH;*, *$ +o1p33p3A@!$I'

  U 1 : 23 4V 65W)6X77

Icl!"IM#'@  A, 12

" : Y3 Z- 68)7'q!"IM@r!I
stA!  #!$u¡v¢!" #$    6[9\: ;F#?7% )  d :<=!> 60123457 "< = 6>"I$£#'/()*!$?

4@A0]457 ^_` 6<a)



F 

 (D7 bBCc 65W0)7 dD E 65W)

wR (D'Ix@y~/7 5FG! 65W])7 2e H 6>?

'bI"I*, K¤Hxz@{¥¦A

4@A0123457 If

g 6fh)

L"J!I'§I*, k¨E"IM'7 JB K 65W])7 "LMN- 6Oi#©/#w #'ª|LH;"MP)7

Q3Rj 6OiP)7 kJ4S 6>

6«r¬ ­®¯°±²³7 'I´®µ±²}~

4@AlmTUn045opqr7 st/v! ;;F¶(k¥¤$I'·

?

u 65W)7

;$!*, 8/¸I"k'#'ª¹/n-Aº$'FI*~ »?AF@e,



  !"VW 45 !

!$¼'H;$@'¶H!"I*, '/ 8 //,MZ _¶:/¦I"F()º.M'I*,

      ! "#$%

m R89J2

KN^(

+Om8ULMN&2k
Q3 

{1OK& $]

#&'()*+,-./ w  0 c+332 / +* 012 34 5 6780xy0PQ

916 6:; 6!6 +333 /Rmf  G0K +332 /SH< =" 6>?@ABCD.* /G w l 2;E F!G5 $% H

¡J b*

$IDJ, KL MῌNO  22b* &¢. c&£+ MD! KHPQR +¤¥f U¦T§. UN. ¨ST 8U!"K V&#K©.$%ª 2 «`¬2k89V WLKXYO Z$ ­W

$%K[\% 6NZ$ &XZ$ ]!"  L 

'N^( &#K

Lx v¯R J(0 wR

QR

R_`a)b*+ c,+ ( de$%f g-K.hQRy h®u]2k

KXQR 5Y#K°yR

2  T/ 1201i2
 2j1. 

2kl3 _`m1 &#! Z±² ³±²mn4$o5a o56*+p/,

[ + ´ \µῌ]¶·Q(-q 27r s2189:2

[ , ´ 5^ WL;l3<22tu v[ - ´ F w2 ;l3K Rxy

[ . ´ 6

0,&u$$[ / ´ KN^( zxy{][ 0 ´ ¶X
[ 1 ´ ¸Rῌ_[ 2 ´ - 









[ 3 ´ +
[ +* ´ 6

|= }2kl3~  >;O[ ++ ´ L

0 +31. //=QR [ +, ´ (?p$y   ( @A[ +- ´ ¹ῌ`6

BC

[ +. ´ a Iῌbc? L<2QRu $Ky =H /[ +/ ´ 8UL

DE= QR > Fº»¼\

GHQR]O b2Isῑῐῌ῏῎ῒ῍
)*+),-.    !"# $%&'(/01 2*34*56 78&'9*:;01 ! 78&<=*>ῌ?@*ABC -.* ! DEFGHIJ<=
K+*1ῌ**/, LMNOPQR 3ῌ0ῌ.+ STRUVTEL : *-ῌ-.1/ῌ/0+2

FAX : *-ῌ-.1/ῌ/0+3

WX

YF

Eomail : kammori@msh.biglobe.ne.jp

Notice about Photocopying
In order to photocopy any work from this publication, you or your organization must obtain permission
from the following organization which has been delegated for copyright for clearance by the copyrightowner of this publication.
Japan Academic Association for Copyright Clearance (JAACC).+ῌ0 Akasaka 3ochome, Minatooku, Tokyo +*1ῌ**/,, Japan
TEL : 2+ῌ-ῌ-.1/ῌ/0+2

FAX : 2+ῌ-ῌ-.1/ῌ/0+3

Eomail : kammori@msh.biglobe.ne.jp

Journal of the Japanese Societyof
Soil Physics
July ῍ῌῌ῍

No. 3+
Contents

Foreword ῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌT. ADACHIῌ +Original Papers
Soil Erosion under Co#ee Trees with Di#erent Weed Managements in Humid
Tropical Hilly Area of Lampung, South Sumatra, Indonesia
ῌῌῌῌAFANDI, T.K. MANIK, B. ROSADI, M. UTOMO, M. SENGE, T. ADACHI and Y. OKIῌ Inﬂuence of Temperature/Water Condition on the Acidiﬁcation Process of Sedimentin Lake Kojima ῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌK. UENO, T. ADACHI and H. NARIOKAῌ+/
Sediment Yield from Various Land Use Practices in a Hilly Tropical Area of
Lampung Region, South Sumatra, Indonesia
ῌAFANDI, B. ROSADI, MARYANTO, NURARIFANI, M. UTOMO, M. SENGE and T. ADACHIῌ,/
Soil water movement under micro-irrigation using a perforated tubeῌῌῌῌῌῌῌῌῌῌῌῌῌῌS. NAKAGAWA, K. SOMA, J. KASHIWAGI and S. SUZUKIῌ-3
E#ects of Drying on Bacterial Activity and Iron Formation in Acid Sulfate Soils
ῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌK. UENO, T. ADACHI and H. NARIOKAῌ.3
Book Review ῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌM. KOMAMURAῌ/3
J. KARUBEῌ0*
Announcements ῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌ0+
Editor’s Postscript ῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌῌ0-Japanese Society of Soil Physics
Department Biological and Environmental Engineering
Graduate School of Agricultural and Life Sciences, The University of Tokyo+ῌ+ῌ+ Yayoi Bunkyooku, Tokyo ++-ῌ20/1, Japan