PLACE IN RETURN BOX to remov- this chockout tram yam record.
TO AVOID FINES mum on or baton duo the.

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MSU Is An Affirmdivo ACNONEM Opportunity Institution

 

EFFECTS OF AGROFOREST RY PRACTICE ON GROWTH OF TEAK,

CROP PRODUCTION AND SOIL FERTILITY

by

Mohamad Samba: Sabarnurdin

A DISSERTATION

Submitted to
Michigan State University
in partial ol’ the fulfilment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY

Department of Forestry

I988

ABSTRACT

EFFECTS OF AGROFORESTRY PRACTICE ON GROWTH OF TEAK,
CROP PRODUCTION AND SOIL FERTILITY

BY

Mohamed Sambas Sabarnurdin

To investigate the ecology of the tumpangsari
agroforestry system as practiced in Java, teak ( Iggggng
grangig L. ) was grown in the Wanagama I forest area 36
has south of Yogyakarta, in combination with rice ( 9:11;
flatly; L. ), corn ( figa_mg1§ L. ) and peanut ( Axggnig
hypgggg L.) in plots with or without a legume ( 59391;
211mm.

Teak grown with rice or peanut performed better
than when grown with corn or without crop. With the
exception of teak-rice combination 16 months after
planting, the effect of acacia was found not significant.
The type of crop significantly affected the performance of.
teak, although the difference between teak grown with rice
and with peanut was not significant. The order of positive
companionship of crops on teak was rice > peanut > corn
and peanut > rice > corn at four and 16 months,
respectively.

No significant reduction of crop yields observed

Mohamad Sambas Sabarnurdin

after the second cropping season. Acacia has shown a sign-

ificant effect on yield of crop on the row basis but not

on‘ the plot basis. Root occupancy of the teak-crop

combination was significantly affected by its distance-
from the teak but not by the depth of the soil. Roots
of the teak-rice combination occupied the soil more
extensively than the other teak-crop combinations.

Nitrogen, P, and organic carbon concentration of the
surface soil decreased significantly after four months,
while that of the subsurface soil increased. The effect
of acacia on soil N was not significant. There was no
significant effects on soil total exchangeable bases for
both surface and subsurface soils.

The findings support the agrisilvicultural practice
during forest establishment, and under the conditions of
the experimental area, the suggested cropping sequence

for tumpangsari is rice-peanut-corn.

To my mother, Toetl
and
in memory of my father, Roekanda.

ACKNOWLEDGEMENTS

In the course of my graduate education at Michigan
State University and especially in the writing of this
desertation, I have incurred debts to great many people
and institutions. However, my first and deepest appreciat-
ion must go to Dr. Donald I.Dickmann for the excellent
guidance, encouragement and invaluable assistance through-
out the doctoral program and during the completion of this
desertation.

The same appreciation is extended to the other
members of my doctoral guidance committee for their
assistance and suggestions : Dr. James W. Hanover, Dr.
Lawrence 0. Copeland, Dr. Michael A. Gold and Dr. Phu V.
Nguyen I have had benefited from their classes and the
intellectual discussions I have had with them.

My special thanks are due to Dr. J. Bud Hart for
allowing me to use the soil lab facilities, and to Eunice
Padley and Leslie Loeffler for helping me with the
equipment.

My special thanks are also due to my colleagues in

the Fakultas Kehutanan Universitas Gadjah Mada ( Faculty

ii

iii

of Forestry of the Gadjah Mada University ). In particular
I wish to thanks Prof. Dr. Achmad Soemitro Prawirodipuro,
Dean of the Fakultas Kehutanan, for giving me chance to
compete for a scholarship, Prof. Dr. Soenardi Prawiro-
hatmodjo, the former Dean for his personal support during
my field work: Prof. Ir. Soedarwono Hardjosoediro, for his
critique, discussion and suggestions; Dr .Ir. Oemi Haniin
Soeseno who allowed me to use the facilities in Wanagama
I; Ir. Pardiyan, who helped me to understand the materials
written in Dutch; Ir. Soedjoko Dirdjosumarto 8.0, and his
wife, Ir. Sri Astuti. for helping me with the equipment,
transportation, and other personal support: and others who
have in various ways helped me during the course of my
field study.

A special expression of gratitude is due to wy wife
Aan who has been constantly a source of invaluable support
during the whole period of my education. She and our two
daughters, Metta and Heggie, shared the burden of the job
I do. For all this, they have my appreciation.

Last but not least I wish to express my gratitude
to the Goverment of Indonesia, the Rockefeller Foundation,
and the Gadjah Mada University for providing the leave of
absence and the financial support for this program, and
also to the Department of Forestry at Michigan State
University for providing me ample facilities and excellent

cooperation throughout the whole program.

TABLE OF CONTENTS

page
LIST or TABLES . . . . . . . . . . . . . . . . . . . . vii
LIST OF FIGURES. . . . . . . . . . . . . . . . . . . . x
1. INTRODUCTION. . . . . . . . . . . . . . . . . . . . . 1
2. AGROFORESTRY REVIEW . . . . . . . . . . .3-23
2.1 Agroforestry. . . . . . . . . . . . . . . . 3
2.1.1 The concept . . . . . . . . . . . . 3
2. 2. 2 The place of agroforestry in forestry
in Java 0 O O O O O O O O O O O O O O O O 7
2.2 Tumpangsari system . . . . . . . . . . . . . . 8
2.2.1 History . . . . . 8
2.2.2 The principles of tumpangsari plantation . 12
2.2.3 The activities schedule of tumpangsari . . 14
2.2.4 The silvicultural implication of tumpang-
sari O O O O O O O O O O O O O O I O O O O 16
2.2.4.1 The application time and durat-
ion oftumpangsari . . . . . . . . l7
2. 2. 4. 2 The effect of tumpangsari on .
trees 0 I O O O O O O O O O O O 18
2. 2. 4. 3 The effect of tumpangsari on
agricultural crops. . . . . . . . 21
2.2.5 Present development of tumpangsari . . . 22
3. MATERIALS AND METHODS . . . . . . . . . . . . . . 24-43
3.1. Area description . . . . . . . . . . . . . . 24
3.2. Plantation establishment . . . . . . . . . . . 28

iv

4.

3.3.

3.4

Par an

.3.1.
.3.2.
.3.3.
3.3.3.
3.3.4.

Statis

RESULTS. .

V

eters measured . . . . . . . . . . . . . . 34
Teak growth parameters. . . . . . . . . 36
Crop parameters . . . . . . . . . . . . 37
Acacia biomass. . . . . . . . . . . . . . 38
Root occupancy. . . . . . . . . . . . 39
Soil fertility. . . . . 39

tical analysis . . . . . . . . . . . . . . 4O
. . . . . . . . . . . . . . . . . . . 41-83

4.1. Effect of tumpangsari on teak. . . . . . . . 44-60

4.1.1

HHHHHH
ummsun

bbbbéh

Effect

4.2.1.
4.2.2.

Acacia
Root 0
Effect

4.5.1
4.5.2

Height of teak 4 months after planting. . .45
Height of teak 16 months after planting. . 50
Diameter of teak 4 months after planting . 52
Diameter of teak 16 months after planting. 54
Leaf area of teak 4 months after planting. 56
Leaf area of teak 16 months after planting.56
Dry weight production . . . . . . . . . . 58

on on crops . . . . . . . . . . . . . 61-69

Crop yields.. . . . . . . . . . . . . . . 61
Crop residues and weeds . . . . . . . . . 65

biomass . . . . . . . . . . . . . . . . . 66
ccupancy. . . . . . . . . . . . . . . . . 67
s on soil fertility . . . . . . . . . . 70-77

Effect on soil nitrogen and carbon . . . . 71
Effect on soil phosporus . . . . . . . . . 75

4.5.3 Effect on soil acidity and extractable

bases .

5. DISCUSSION . .

6. SUMMARY AND CONCLUSION

BIBLIOGRAPHY. . .
APPENDICES

Appendix A

F values and associated probabilities of
influencing N concentration
and subsurface
four months after

variables

of surface

( 15-30 cm )

planting.
Appendix B

F values and associated probabilities of
influencing P concentration
and subsurface
after

variables
of surface

planting.

( 0-15 )
( 15-30 cm ) soils four months

vi

( 0-15 )

soils

76

78

85

‘88

93

94

LIST OF TABLES

Table

2.1 Land and Forest area in Java . . . . . . . . .
2.2 Site Preparation . . . . . . . . . . . . . . .
2.3 Seed preparation . . . . . . . . . . . . . . .

2.4 Planting . . . . . . . . . . . . . . . . .
2.5 Tending . . . . . . . . . . . . . . . . . . .

2.6 Agricultural; cropping pattern of Tumpangsari
in Bojonegoro, East Java . . . . . . . . . . .

2.7 Mean height and mean girth at breast height of
teak as influenced by crops in three observ-
ations after establishment in December 1933. .

2.8 Growth of Gmelina at 15 months from planting
out either alone or under taungya . . . . . .

2.9 Yield of some crops under tumpangsari and
average farming in Java . . . . . . . . . .

3.1 Treatment combination applied to teak . . . .

3.2 An analysis of variance table of a split plot
design . . . . . . . . . . . . . . . . . . .

3.3 Treatment factors observed in the soil data
analysis . . . . . . . . . . . . . . . . . . .

3.4 Type of data, factors observed and statistical
procedures . . . . . . . . . . . . . . . . . .

4.1 Height, diameter and leaf area of teak grown
with and without various crops four and 16
months after planting . . . . . . . . . . . .

4.2 F values and their associated probability ( P )
of intercropping variables influencing height,
diameter and leaf area of teak four and 16
months after planting . . .

vii

15

15

15

16

19

20

22

28

38

39

40

44

45

viii

Comparison of mean values of height, diameter

and leaf area of teak grown with and without
various crops four and 16 months after

planting . . . . . . . . . . . . . . . . . . . . .

F values and associated probabilities of acacia
factor as it influenced height, diameter and

leaf area of teak grown with rice 16 months

after planting . . . . . . . . . . . . . . . . . .

Biomass allocation of 4-month-old teak seedlings
grown either alone or under tumpangsari. . . . . .

F values and associated probabilities of vari-
ables as they influenced the biomass para-
meters of teak . . . . . . . . . . . . . . . . . .

Comparison of the mean values for root, stem,
leaf and total biomass parameters of teak
four months grown with crops . . . . . . . . . . .

Yield of crops obtained from a tumpangsari
plantation with teak at first and second
year of cropping . . . . . . . . . . . . . . . .

F values and the associated probabilities of the
acacia as it influenced the yield of crap . . . .

F ratio testing group variances ( F ) and the
associated probabilities ( P ) of the crop
Yields 0 O O O O O O I O O O O O O O O O O O O O O

F values and associated probabilities of the row
position factor as it influenced crop yields
obtained from the tumpangsari plantation with
acacia interplanted . . . . . . . . . . . . . . .

Yield of crops on the row to row basis. . . . . .

Crop residue ( fresh weight ) from a teak
tumpangsari plantation . . . . . . . . . . . .

Main weeds found in the teak w/o crop plots and
their percentage of total fresh weight. . . . . .

The biomass of acacia as influenced the neigh-
boring vegetation . . . . . . . . . . . . . . . .

Analysis of variance of root occupancy in the
soil in respect to its teak cropping combinat-
ion, distance from teak, and soil depth . . . . .

48

51

58

60

6O

61

62

63

64

64

65

66

66

68

4.20a

4.20b

ix

Mean soil root occupancy of teak-crop combinat-
ion at three different distances from teak. . . . 69

Mean root occupancy of soil under teak-crop
combinations. . . . . . . . . . . . . . . . . . . 69

Some characteristics of surface ( 0-15 and 15-30
cm depths ) soil at the initiation of the
trial 0 C O O O O O O O O O O O O O O O O O O O O 70

Some chemical characteristics of surface ( 0-15

and 15-30 cm depths ) soil under tumpangsari
plantation before trial and four months after
planting . . . . . . . . . . . . . . . . . . . . 72

Extractable bases of surface ( 0-15 and 15-30
cm depths ) soil under tumpangsari plantation
before trial and four months after planting. . . 72

F values and associated probabilities of some
variables influencing soil chemical
characteristics . . . . . . . . . . . . . . . . . 73

F values and associated probabilities of some
variables influencing N, P, and organic carbon
concentration of surface ( 0-15 cm ) and sub-
surface ( 15-30 ) soils four months after

planting . . . . . . . . . . . . . . . . . . . . 75

LIST OF FIGURES

Figure

2.1

3.1

3.4

3.5

4.1

A schematic life cycle of teak under the
present management system . . . . . . . . .

A map of Java showing Yogyakarta and the
the Wanagama I . . . . . . . . . . . . . . .

Weekly rainfall during the first four
months of plantation . . . . . . . . . . . .

Field situation of the experimental plot . .
Plants arrangement in the plots . . . . . .
Sampling points in a plot . . . . . . . . .
Height growth curve of teak in association
with crops during the first four months of

plantation . . . . . . . . . . . . . . . . .

Height of teak in association with crops
four months after planting . . . . . . . . .

Height of teak in association with crops
16 months after planting . . . . . . . . . .

Diameter growth curve of teak in association
with crops during the first four months of
the plantation . . . . . . . . . . . . . . .

Diameter of teak in association with crops
four months after planting . . . . . . . . .

Diameter of teak in association with crops
16 months after planting . . . . . . . . . .

Leaf area of teak in association with crops
four months after planting . . . . . . . . .

page

. 17

49

xi

Leaf area of teak in association with crops
16 months after planting . . . . . . . . . . .

Biomass allocation of teak in association with
crops four months after planting . . . . . .

57

59

1 . INTRODUCTION

Agroforestry is a system of land management that
seems suitable for ecologically fragile areas since it
combines the protective ( and also productive ) character-
istics of forestry with the productive attributes of agri-
culture. In the words of King ( 1979 ), " It conserves and
produces".

The practice of agroforestry on forest lands known
as "tumpangsari" ( an Indonesian term for taungya ), is
generally practiced during the agrosilvicultural stage of
the teak life cycle ( Figure 2.1 ), although some other
alternatives are available ( Becking, 1928 ). In this
system farmers are permitted to grow their crops between
rows of trees on condition that they tend the trees
during the intercropping period, which lasts for two
years ( Kartasubrata, 1978 ). Tumpangsari is an old
practice waiting for more scientific informations for
further improvement. As was stated by Atmosoedaryo and
wijayakusumah ( 1979 ), foresters have taken interest only
in the technical and production aspects of tumpangsari
while leaving behind the need for intensive investigation
into its ecological aspects The principal motive of a

taungya system, which was a reduction in the cost of stand

1

establishment by exploiting people’s poverty ( Contant,
1979 ), has changed. At least in Indonesia, there is an
ongoing tendency to get into a fairer cooperation between
both the forest service and the farmers. Attention is
also being given to the general improvement of forest-
farmers’ living conditions and the diversification of
their farming activities ( Kartasubrata 1978, Atmosoedaryo
and Banyard, 1979 ). At present, a high reliance on
tumpangsari system to produce sufficient food for forest
farmers is questioned ( Wiersum, 1980 ), because less and
less land is alotted to farmers and slow improvement
of the system itself has occurred.

The present study was carried out in response
to the problems mentioned above to add some information on
the interference between teak and crOps grown with it.
More specifically, the main objectives of the study were
to document the effects of interplanted crops on growth
and productivity of teak, measure yield of the interplant-
ed crops, and assess changes in nutrient status of the
soil. Results of this study might be of important for
recommending l) the proper kind of crop to be grown with
teak, and 2) the cropping pattern for tumpangsari under a
condition similar to the experimental area. In addition,
this study also provides additional ecological data which
should be considered in determining whether or not

tumpangsari should be practiced on forest land.

2 . A REVIEW OF AGROFORESTRY AND THE TAUNGYA SYSTEM
IN FORESTRY PRACTICE IN JAVA

2 . 1 AGROFORESTRY

2.1.1. Theeonoept.
I Agroforestry, in its simplest terms refers to a
practice of growing woody plants with agricultural crops
and or domestic animals together on the same land. Many
definitions have been made describing agroforestry; e.g.
those written in the first issue of the Agroforestry
Systems Journal ( Annon, 1982 ). The one that is being
used by the International Cooperation for Research in
Agroforestry ( I.C.R.A.F ) as stated by King and Chandler
( 1978 ) is : " Agroforestry ........ a sustainable land
management system which increases the overall yield of the
land, combines the production of crops ( including tree
crops ) and forest plants and/ or animals simultaneously
or sequentially, and applies management practices that are
compatible with »the cultural patterns of the local
population."
Most and in the tropics is not suitable for agri-
culture; either it is too dry, too steep, too infertile,

or prone to annual flooding. Only 11 % of the land of the

tropics is flat enough for arable agriculture (Mongi,
1979), implying that for most of the land, forest is the
most suitable cover. However, due to population pressure,
this ideal type of land cover, forest, has to be
sacrificed for the production of people’s basic needs,
food.

The premises on which the concept of agroforestry is
based are partly biological and partly socio-economic
(King,1979 ). In general, trees in the forest have the
ability to take nutrients up from deep within the soil
profile, ( at a depth not exploited by roots of agricult-
ural crops ), convert and utilize nutrients for production
of plant material, and recycle them in the form of litter,
which in turn will be transformed into humus and later
incorporated into soil. Forests have an efficient nutrient
cycle. The physiognomy of a forest is such that it
provides protection from the effects of precipitation
because the canopy or the intermediate strata of the
forest reduce the potential impact of rain drops on the
soil, so that erosion can be minimized.

Boerboom ( 1981 ) stated the tree components in
agroforestry will have one or more of the following
functions :

a. To produce a product for local consumption by man and

cattle and for marketing externally.

b. To improve or have a stabilizing influence on the
environment, locally and / or in adjacent areas
( site improvement )

c. To create favorable conditions for the growth of other

crops ( habitat improvement ).

When introducing trees to agricultural land being
occupied with a given crop, consideration should be given
to some tree characteristics ideal for agroforestry

( King, 1979 ) :

- amenable to early wide spacing:

- good self pruning or ability to tolerate a relatively
high incidence of pruning:

- low crown diameter-to-bole diameter ratio:

- light branching habit:

- tolerant to lateral shade, if indeed not to full over-
head shade in the early stages of growth:

- phyllotaxis which permits the penetration of light to
the ground:

- phenology, particularly with respect to
leaf flushing and leaf fall, that is compatible with
the growth of the companion annual crop:

- good litter producer with fast decomposition;

- the root system and root characteristics ideally should

result in the exploration of soil layers that are

different from those being tapped by the agricultural
species: and

- be an efficient nutrient "pump".

The socio-economic premises for introducing agro-
forestry are even clearer. Forests in developing countries
are disappearing under the pressure of population. More
and more forest land is being converted by people who
need land to produce food for their very existence,
although the areas are not well suited to arable
agriculture. Another factor contributing to this decrease
of forest area is the time scale in the forest production
cycle. Forestry practices typically result in delayed
returns that do not meet the immediate needs of the local
population. There is also the risk that the original
planter might not profit from future yield due to in
security of land and tree tenure. Shifting cultivation,
which under low population pressure is considered as the
most suitable method of manipulating the forest environ-
ment, is no longer a viable alternative, because the time
required for a proper fallow period can no longer be met.
Finally, poor agricultural practices in the past indirect-
ly contribute to the encroachment of forest land through
the creation of abandoned land which is difficult to

reclaim back into agricultural production.

2 . 1 . 2 . The place of Agroforestry in Forestry in Java

Agroforestry ventures can be carried out either on
agricultural land or on forest land. Outside the forest
there is enormous potential for introducing trees on lands
that are conventionally seen as strictly agricultural
( F.A.O., 1981 ). However, forest land can also be used
for a greater food production base for the rural
population, although this means a specific approach of
forest management beyond traditional practices.

The forest cover of Java is 22.7 % of the total
land area ( Table 2.1 ). Most of the forest land is
surrounded by densely populated villages generally
inhabitated by low income, subsistence farmers with a
very limited chance of getting alternative sources of
income. This socio economic situation was clearly describ-

ed by Atmosoedaryo and Banyard ( 1979 ) as :

"...... an all too common problem facing forest managers in
areas of dense population is how to protect the forest from
destructive human activities. There are those who steal and
destroy for financial gains and against whom preventive and
repressive measures will always have to be taken. There
are others, however, obtaining fuelwood, grazing, building
material, and even arable land whose very existence depends
upon the forest. The problem is aggravated by the fact that

foresters can often sympathize with the motive of the

offenders. A fine of being caught only make matters worse

for the peasant and his family...."

The problem described above might also be true for
forest managers in other developing countries. It shows
how impossible it is to practice a good forest management
with a total ignorance of the welfare of the people living

in or near the forest.

lahle 2.1. Land and forest area in lava ( in hectares 1

 

 

 

1. Total land area 13,218,700
2. Forest area: 3,007,222
2.1. Production forest
2.1.1. teak 1,053,700
2.1.2. non teak 783,568
2.2. Protection forest and Natural reservation
2.2.1. Protection forest 1,152,942
2.2.2. Natural Reservations 419,942
3. Percentage of forest to total land 95;; 221

 

 

Source 1 Perhutani 1 1981 1

2 . 2 . TUMPANGSARI SYSTEM

2.2.1. History
Forest management in Indonesia started in the late
19th century when the Nederland Indische Goverment

invited in some German foresters and asked them to

establish a forest management plan for the Japara -
Rembang forest district in Central Java. Later, similar
plans were also established for all other forest districts
in Java. At present, the State Forestry Corporation "Perum
Perhutani", which was established in 1963, is responsible
for the management of forest land. The corporation,
although essentially a profit making organization, has an
obligation to support the government’s policy of improving
the living standards of the rural community ( Atmosoedaryo
and Banyard, 1978 ). One of the available ways is to
involve villagers in reforestation activities. The rate
of teak reforestation under tumpangsari system is approx-
imately 40,000 hectares per year ( Kartasubrata, 1978 ),
which, on the average, will include 160,000 farmers.
Taungya ( taung= hill, ya= cultivated plot ) is a
Burmese word. This practice was started in Burma in the
19th century as a modification of the undesirable practice
of shifting cultivation. The Taungya system permitted
squatters to grow their crops between rows of trees on
condition that they tended the trees during the inter-
cropping period, which lasted for two years ( Karta-
subrata, 1978 ). The system was introduced into Indonesia
in 1875 by Buurman, a forest district administrator of

Pemalang, central Java, and is locally known as tumpang-

sari.

10

The objectives in applying the tumpangsari system
are:

1. to cut the establishment cost of a plantation,

2. to obtain additions income from agriculture during the
juvenile stage of the tree stand,

3. to gain better maintenance of the young tree stand

4. to reclaim wasted lands by means of agriculture before
stand establishment,

5. to solve meet the local shortage of good agricultural

land.

Land hunger and population pressure, combined with
unemployment, have been the conditions under which taungya
works ( Contant, 1979 : King, 1979 ). The similar con-
dition also is true for tumpangsari, which has been an '
obligatory technique for teak establishment in Java since
1881 ( Becking, 1928 ). Before tumpangsari was introduced,
there were at least two methods of planting: the "blan-
dong " system, which is an artificial regeneration system
employing blandongs ( logging worker ) as the paid labor,
and the natural regeneration system ( Hart, 1927 ). During
the 1900-1930 period, foresters were strongly divided
into two groups, one favoring tumpangsari and one against
it. Wehlburg ( 1908 ) and Thorenaar ( 1928 ) suggested
that tumpangsari should be rejected due to several dis-

advantages durinq the tumpangsari or after the contractors

ll

( farmers ) have left. During tumpangsari soil fertility
is decreased due to strong withdrawal of nutrients by
agricultural crops and the practice of burning during
land clearing process. Furthermore, long exposure to sun
and rain causes a rapid break down of humus and the danger
of accelerated leaching due to intensive soil tillage.
After the contractors have left, teak growth decreases
because no tillage is done and because of strong compet-
ition from alang-alang ( Imperata cvlindrica ) a dominat-
ing weed which increases rapidly because competing
beneficial herbs and shrubs, are suppressed by
cultivation.

Lugt ( 1909 ), a tumpangsari supporter responding to
Whelburg, argued that 1. during tumpangsari, the soil is
not bare but covered with crops, while the interplanted
trees of kemlandingan ( Leucaena glauca ) cover the soil
after the contractors leave: 2. the maintenance of crops
has a far greater favorable influence on the physical con-
dition of the soil than the presence of natural weeds
( mostly alang-alang ): and 3. deep soil cultivation is
not necessary, since cultivation which is followed by
mulching using crop residues maintains soil structure.
Lugt further stressed that " often it is not the method
used but rather the way it is done that is incorrect"

Thorenaar ( 1929 ) relaxed his opposition, suggest-

ing that the duration of the tumpangsari be shortened to

12

only half a year, only rice be allowed as a companion
crop, planting without tillage, felling be restricted to
the monsoon season, with no or just a short period of
standing girdled, and maintenance of kemlandingan under
growth after agricultural cropping is ceased.

Boer ( 1929 ), disagreed with Thorenaar’s suggestion
of using only rice, and the idea of reducing the duration
of tumpangsari. He stated that in some areas maize was
preferred to rice, and reducing the time of tumpangsari
means increasing the possibility of invasion of wild
climbing plants. However, he agreed that soil cultivation
has to be reduced as much as possible. He also pointed out
that the expenses involved in preventing the teak from
being overgrown in plantations established without the
intervention of contractors were extremely high. This
opinion was also shared by Coster and Hardjowasono (1935)
They found that the teak raised in tumpangsari is only
" just a little behind " that of pure plantations which
could be compensated by other advantages, such as the
reduction in the cost of planting. So they concluded that

tumpangsari is justifiable.

2 . 2 . 2 . The principles of tumpangsari
Tumpangsari in Java is carried out as follows.
During plantation establishment, a 0.5 ha parcel of land

is alotted to each farmer. The income from this amount of

13

land, along with some additional work ( farmers also work
on other forestry activities such as logging and road
maintenance during their agricultural off-season ) is
considered sufficient for survival. The working capacity
of a simple farmer, using only manual equipment, is about

1 "bahu" ( bahu means shoulder ) or about 0.7 ha ( Hardjo-
soediro, 1972 ). This area of land will keep the farmer
and his family busy throughout the year. With the increas-
ing population, the size of the land parcel is becoming
smaller and smaller, and in some forest districts it is
down to only 0.125 be per farmer. However, the average
size of land parcel alotted to a farmer at present is
0.25 ha ( Perhutani, 1981).

Teak is regenerated by planting 3 to 5 seeds at each
'spot. The spacing generally is 2 x 1 m or 3 x 1 m,
depending on the soil "bonita" ( site class ). The Perum
Perhutani workers mark the planting spots with colored
poles, after which the farmer takes over most of the act-
ivities until the end of the tumpangsari period. The
farmer is allowed to grow rice ( ggyzg sativa ),

corn ( Zea mays ), tobacco ( Nicotiana tabacum ), chili

pepper ( Capsicum annuum ), peanut ( Arachis hypogga ),

and soybean ( Glycine max ). Except under certain
condition, cassava ( Manihot esculenta ), sweet potato

 

( Ipomoea batata ), potato (Solanum tuberosum ), banana

141

( Mus; naradisiaga ), plantain ( Mgsa sapientum ) and

climber crops, are not permissible ( Kartasubrata, 1978 ).

2 . 2 . 3 . The activities schedule of Tumpangsari

Tumpangsari is carried out for 29 months starting
from January each year. The activities of tumpangsari as
described by Perhutani ( 1974 ) and Kartasubrata ( 1978 )
can be grouped into four categories : site preparation,

seed preparation, planting, and tending ( Tables 2.1 -

2.5 ).

Table 2.2 Site Preparation

 

 

Kind of Honth of
activities execution
1. A letter of instruction is issued 01
2. Boundary and inspection paths aapping 01
3. Field aarling of houdaries and inspection paths. 02-03
4. Plantation contract agreeeent resuae 02-03
5. Land clearing 03-04
6. Soil tillage 1 05-06
7. Soil tillage 2 07-08
8. Construction of erosion control structures 07-08
9. Soil tillage 3 08-09
10.harking of plant-spot 09

 

Table 2.3. Seed preparation

 

 

Kind of Honth of
activities execution
1. leak seed collection 08-09
2. collection of leguae seed 05-10

3. collection of non-teat seed 06-09

 

155

Table 2.4 Planting

 

 

Kind of Month of
activities execution
l. Planting teak seed 09-10
2. lnterplanting leucaena 10
3. Hedge planting 11-12
4. Planting non-teak species 12

5. Blank filling 1 using seeds 1
6. Blank filling ( using seedlings or stuaps 1 13-15
7. darting spots for blank filling next year 22-23

12 and 15-16

 

Table 2.5. Tending

 

 

Kind of loath of
activities execution
1. Pruning of leucaena 16-18 and 23-25
2. Selection for ultieate seedling 14-15 and 28-29
3. Last cleaning before contract ends 28-29
4. Contract ends, plantation subaission 29

 

Within the 29-month operation of tumpangsari

there are

usually four to five rotations of agricultural crops. The

example in Table 2.6 was given by Rachadi ( 1978 ), based

on his experience in Bojonegoro, East Java

115

Table 2.6 : Agricultural cropping pattern of tuapangsari
in Bojonegoro, East lava 1 C8 corn; 588
soybean; T: tobacco; it8 dry rice paddy.

 

year aonths
1 2 3 4 5 6 7 8 9 10 ll 12

 

one 1 C i 58 l 1 T l 1 - - -
two R i C l 1 C 1 SB 1 1 - - -

three R l

 

Source: Rachadi 1 1978 l

2 . 2 . 4 . The Silvicultural Implications of Tumpangsari

Along the life cycle of teak there are several time
segments available for applying the tumpangsari system. In
selecting the time and duration of tumpangsari one has to
consider the types of crops, the cultivation technique, and
the development stage at which trees are less affected by
crops, although in a particular situation other non-

technical reasons might be more significant.

2 . 2 . 4 . 1 . The application time and duration of Tumpangsari

Under the current management system, teak needs to
grow 60 to 80 years before it is harvested. During that
period of time, teak plantations are subject to either

agricultural or forestry treatments as shown in Figure 2.1.

137

F +1 *2 F=30 F+50

 

-2 -i <---intensive tending ------ > or F+80.
( >< - >
figro silvicultural stage
silvicultural stage

 

Fig. 2.1 fl schematic life cycle of teak under present nanagenent susten.

F -2 = Girdling period
F 3 Cutting
F -0 = after cutting activities ( Land preparation
and farner reqruitnent for the next plantation ).
F 2-30 = Intensive tending. thinning etc.
F 30 = Thinning conplet
F 60-80 = Cutting .

The intercropping period in tumpangsari system may vary
according to local conditions. Becking ( 1928 ), dist-
inguished three alternatives: 1. agricultural crop cultivat-
ion before stand establishment, 2. agricultural crop
intercropping starting at the time of stand establishment,
3. stand establishment at the same time as the start of
the second crop rotation

In addition, there is the possibility of starting
agrisilviculture when the stand reaches about 30 years of
age. This possibility is based on the presumption that

thinnings have been completed, reducing the number of

18

stems to 100-150 per hectare and that the teak crowns have
reached maximum size. As teak becomes older, crown
diameters become smaller, whereas diameter growth may
still increase ( Hollerwgen, 1954 ). Teak must be given
an advanced growth of at least 30 years, after which time
it will not suffer from root competition by the
intercropped herbs ( De Veer , 1958 ).

At present, the second alternative suggested by
Becking is being used, i.e. beginning intercropping at the
same time as the tree planting, lasting for two years and
four months ( Perhutani, 1974 ). However, there is a
developing tendency to lengthen the tumpangsari time to 5
years. However, the reason is more psychological than
technical ( Hardjosoediro, pers. comm.). For the first 5
years, teak stands are still vulnerable to disturbances
caused by cattle since they are considered as favorable
sites for people to herd their cattle. Permiting the
farmers to stay longer will psychologically prevent this
practice, since people will unlikely herd their cattle

onto a field if they are convinced that the field is

"owned" by someone.

2 . 2 . 4 . 2 . Effects oftumpangsari on trees
Teak is very sensitive to crown as well as root
competition. Its growth may be severely impeded by root

competition of mixed species. Coster ( 1933) observed that

19

after six years teak raised with Lantana shrubs ( Lantana
gamara ) had 33 % less growth in diameter than the
adjoining pure teak. Research conducted by Coster and
Hardjowasono ( 1935 ) demonstrated the negative effects of
crops on the growth of teak ( Table 2.7 ). They found
that all crops studied retarded the growth of teak,
especially cassava. The order of harmfulness of crops in

their study was : cassava > dry paddy rice > corn >

peanuts > goat pepper ( Solanum spp ).

A similar effect of crops on trees was shown by
gmelina trees ( Gmelina arborea ) grown under a taungya
system ( Table 2.8 ). These results show a non significant
difference in height and stem diameter of gmelina trees
raised under taungya compared to a pure plantation. Under
narrower spacing, taungya-raised gmelina seems to grow

better in diameter than pure-planted gmelina.

21)

Table 2.7 Mean height and aean girth at breast height of
teak as influenced by crops in three observations
after establishaent in Deceaber 1933.

 

 

Height Birth

1 l of control treataentl 1 ca 1

liar. Aug. Feb. Feb.

1934 1934 1935 1935

Teak - control 100 100 100 .9
Teak - rice f corn 83 85 95 0 3
Teak - peanuts/pepper 79 87 94 .6
Teak - corn 71 84 92 .8
Teak - rice 92 82 96 10.0
Teak - cassava 58 55 74 10.0

 

Source : Coster and Hardjowasono 1 1935 1

Table 2.8. Growth of geelina at 15 aonths froe planting out
either alone or under taungya. Annual crops were
harvested 5 aonths before.

aean values.

Figures are overall

 

diaaeter height

 

Cropping treataent Spacing ca a
1 x 2 e
Beelina alone 5.41 6.04
Beeline with eaize 1 twicel 5.30 5.74
Seeiina with beans 1 twice 1 5.55 5.84
Seeiina with beans and eaize . 0 6.03
2 x 3 a
Seelina alone 8.80 6.12
Seelina with aaize 1 twice 1 .52 5.55
Seelina with beans 1 twice 1 7.31 5.34
Saelina with aaize and beans 7.27 5.38

 

Source: 1 Coabe and Sewald, 1979 as cited in Budowski: 1983 l.

21

2 . 2 . 4 . 3 . The effect on agricultural crops

Intercropping may also have a negative effect on
the yield of component crops. However, most research in
tumpangsari has paid inadequate attention to the "agro"
side compared to the "forestry" side.

To the critics, tumpangsari is just another form of
shifting cultivation called "guided shifting cultivation".
where the shifting is guided by the management of tree. By
relying on natural soil fertility only, yield of crops
grown under tumpangsari will undoubtedly follow the same
trend as that grown under shifting cultivation. For
example Hauck ( 1967 ) found that the yields of maize
grown under shifting cultivation were less in the second
and third year than that in the first year.

Since a tumpangsari plantation is usually established
on fresh cleared forest land with higher natural fertility,
it is plausible that the yield of crops grown under
tumpangsari would be greater than the average yield of
crops grown on general farm lands ( Coster and Hardjo-
wasono, 1935 ). However, more recent data showed a slight-
ly different result. Without additional inputs, the yield
of crops under tumpangsari was less than the average farm
yield. Rachadi ( 1978 ) kept the yield of dryland rice
under the tumpangsari higher by using good seed and

fertilization, in an intensive approach to tumpangsari

( Table 2.9 ).

222

Table 2.9. Yield (in Kg/Ha.1 of soae crops under tuapangsari
and average faraing in Java. Yields aarked !
were froa intensified tuapangsari.

 

 

 

 

Crops Tuapangsari Average of Java
1935 1978 1981 1935 1983

Dryland rice 2037- 2284 1250 1690 1200 1794
3250 4

Corn 1000- 1540 1250 1500 990 1636
2250 a

Cassava 9400- 15880 - - 8100 9800

Peanut 2300 - - 730 927

 

Source: Coster and Hardjowasono 1 1935 1 3 Rachadi 1 1978 1
Perhutani 1 1981 1 3 8.P.S. 1 1984 1

2 . 2 . 5 Present development of tumpangsari
Under the tumpangsari system farmers practice their
agriculture under some restrictions, i.e. limited crop

selection and competition of forest trees with their

crops. Perhutani ( 1974 ) allowed only maize, rice,
tobacco, peanut and chili pepper, while cassava and
other crops which have their underground portion

harvested, were prohibited. However, for socio economic
reasons, the regulations are now being somewhat relaxed.

Farmers are now allowed to grow cassava as a row border

23

only. Also, potato can be planted under careful super-
vision, such as in a plantation project called "MAMA"
( Martodiwirjo, 1981).

To obtain better yields, forest farmers are encour-
aged to follow the general agricultural intensification
program being practiced by regular farmers. The program is
called " Panca Usaha Tani ", which encompasses five en-
deavors in agriculture : 1) the use of good seed, 2) better
soil tillage, 3) fertilization, 4) pest and disease con-
trol, and 5) correct adjustment of planting time in relat-
ion to rainfall.

However, the application of fertilizers in tumpang-
sari might need to be followed by some adjustments in the
initial spacing. It was observed by Soekotjo ( 1975 )
that fertilization not only increased agricultural crop
production but also stimulated the growth of teak so that
canopy closured occurred earlier. This condition is
disadvantageous farmers, since it means they will have to
leave their land parcels sooner. The actions leading ,to
spacing adjustment taken by the Perum Perhutani are still
in the its experimental stage, but changing the initial
spacing from the 3 x 1 m standard to 6 x 1 m is being

considered.

3 . MATERIAL AND METHODS

3 . 1 Area description
The study has been conducted on compartment 17 of
the Wanagama-I Forest Research Area of the Gadjah Mada
University, Yogyakarta, Indonesia. The area is situated
about 36 km south of Yogyakarta at 200 m above sea level.

I

Geographically, this area lies between longitude 110° 31
01" to 110° 31,41" East, and latitude 7° 31'19" to 7° 54'
46" South ( Figure 3.1 ).

Wanagama-I has an annual rainfall of 2,147 mm, an
average daily temperature of 25.10 C and a relative humid-
ity of 85%-90% during rainy seasons and 70%-80% during dry
seasons.

The months from April to October are generally
drier than the rest of the year. Months with less than
60 mm rainfall are categorized as dry, while those with
more than 100 mm rainfall are classified as wet. The
'annual averaged number of drier months of 4.4 combined
with the annual averaged number of the wet months of 7.0,
placing this area into the C climate type category of
Schmidt & Ferguson, which is equivalent to the Ama

category of the Koppen's climatic classification system

( Sukanto, 1969 ). A histogram of monthly rainfall during

24

25

the 16 months of plantation is displayed in Figure 3.2.
The experimental site has a gentle topography with
1-2 % slope A soil profile adjacent to the experimental

site showed the following characteristics :

l. horizon 1-3 cm deep: litter and humus ( Ao )

2. horizon 3-18 cm deep of (5YR3/3) color, moderate
to low organic matter and well rooted, has a clay
loam texture, granular structure and firm consist-
ence ( A )

3. horizon 18-130 cm deep, lighter in color ( 5YR4/6 ),
clay loam texture with sub angular blocky structure
and firm consistence. Plithite concretions are found

in the upper part of this horizon ( B ).

The described characteristics and the presence of
plinthite concretions put the soil into an oxisol type of
the USDA soil classification system (1975 ). In the older
clasification, the soil of this area was classified as a
lateritic and latosols complex. The soil of the
surrounding area might be a transition between soils of
the Baturagung soil zone and soils of the Central zone, as

described by Khan (1964) and Darmokusumo (1986).

26

 

 

  

 

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27

 

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rainfall 1 mm )

m m m m .m a

flu
1988

1988

ML

1986 to Mar.

flu

Monthly rainfall of the Wanagama I
during Nov.

Figure 3.2

213

3 . 2 Plantation establishment

In this study teak was grown following the
practice of tumpangsari, in combination with crops either
with or without Acacia villosg interplanting. The treatment

scheme applied to teak is given in Table 3.1.

Table 3.1 Treataent coabination applied to teak

 

Code Description

 

LC Teak grown wl corn in plot wl acacia
LR Teak grown wl rice in plot wl acacia
LP Teak grown wl peanut in plot wl acacia
LT Teak grown wlo crop in plot w/ acacia

ILC Teak grown wl corn in plot wlo acacia
NLR Teak grown w/ rice in plot wlo acacia
ILP Teak grown wl peanut in plot wlo acacia
ILT Teak grown w/o crop in plot wlo acacia

 

The teak grown in the w/o crop, LT and NLT
treatments, was actually exposed to weed interference.
Under the tumpangsari system competition continually
controlled by farmers as they weed their agricultural
crops. In a non tumpangsari plantation, weeding is carried
out by paid workers who clean about 25 cm of the ground
surrounding a tree ( patch weeding ). This practice was

used in this experiment.

29

The experimental plots were established on freshly
cut forest land area formerly covered by a kayuput
oil ( Melaleuca lgucadendron ) stand. The plots were
arranged within three blocks using a split plot design.
The acacia, factor A, was assigned at random to the whole
plots within each block: the crops, factor B, were
assigned at random to the subplots within each main plot.
The whole experimental area was separated from the
adjacent stands by a 8 to 10 m wide buffer zone of
land covered by a mixture cropping of rice, peanut, corn,
cassava ( Manihot esculenta ), and gajahan grass
( Setaria spp ). The closest forest tree plantation

outside the buffer is a provenance trial stand of

Eucalyptus urophylla established in 1983 ( Figure 3.3 ).

3O

 

EflaflnmLummmmmkmaaumd

 

 

 

 

 

 

Inspection roan

block 2

“Beam

“BEBE

“BEBE
“BEBE

block 1:

~—--

. WW stand

 
  
  
  
  
  

D

farmers‘
crops

 

 

Sela
Figure 3.3
Field layout of the experimental plot
L = Plot w/ acacia NL = Plot w/o acacia
C = Teak w/ corn R = Teak w/ rice
P = Teak w/ peanut T = Teak w/o crop

31

Plant materials used in this experiment were obtained from
the following sources : teak fruits from a single stand in
the Randublatung Teak Seed Production Area : Acacia
yillggg seeds from the Wanagama-I: and agricultural seeds
from the Patuk Agricultural Extension Center, a local seed
distributor. .

Upon receipt, teak fruits were separated into size
classes. Only fruits with diameter more than 14 mm were
used in this study. The selected fruits were then planted
in each of the 24 8 x 6 m plots, at 3 x 1 m spacing.
Interplanting a row of brushy legume between two rows of
teak for erosion protection, soil improvement, and
fuelwood is a common practice in tumpangsari. In this
experiment, Acacia villosa was selected simply because it
is a common species being used in forestry in this area.
It is a legume originated in the islands of Curacao, Aruba
and Bonaire in West India and was introduced to Bunder,
Yogyakarta in 1920, to replace Leucaena qlauca, another
legume Acacia villosa is superior to Leucaena glauca
because of its better adaptation to drier regions, slower
growth, and because it gives no shade to teak. Using this
species also reduces pruning frequencies to the minimum
(Verluys, 1922). Acacia villosa, hence-forward will be
called acacia, was planted in half of the 24 plots in a
continuous row. The acacia row was laid out in the middle

between two rows of teak. Crops, i.e upland rice ( Oriza

32

§a§iva), corn ( Ag; mgyg ), and peanut (Arachis hypogea )
were planted within the designated area which was
separated by 0.25 m from the teak or acacia rows. As many
as three fruits of teak were planted around each spot, but
after germination they were reduced to only one seedling
per spot. Acacia seeds were sowed in a continuous row
about 15 g.m-1. Peanut and rice seeds were planted at 25
x 25 cm spacing, two and four seeds per spot, respectively.
Corn was planted three to four seeds in each spot at 50 x
50 cm spacing, then reduced to only two plants in each
spot. In each plot there were 20 rows of rice or peanut or

12 rows of corn. The arrangement of plant components in a

plot is displayed in Figure 3.4.

323

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

err——+ re w--—-—A e
.. 1
I»
e * e ,, e
* I
I-
a e e ‘1' 0
It It
* I
It
‘1 1
‘-
1.-' .. O
O O O
O C O
‘O O ‘O
O .A_ O 0
1e '

 

 

 

Figure 3.4 Plants

[34:00»

arrangement in the plots

A plot with interplanted acacia
A plot wlo interplanted acacia
Teak

acacia
area designated for crops

 

34

3 . 3 Parameters measured

During the first four months, i.e. the first
cropping season, growth of teak, yield of crop, acacia
biomass, soil root occupancy, and soil fertility changes
were monitored. At 16 months after planting, measurements
of the growth parameters of teak ( except biomass ) and
yield of crops were again taken. Neither watering nor
fertilization was applied during the experiment: however,
weeding within the teak-crop plots was applied manually,
simulating one of the farmer's important obligations in
tumpangsari. Figure 3.5 shows how sampling points were

distributed within a plot.

35

 

 

 

 

 

 

 

 

 

 

 

 

 

0 8 saeple tree

00' 2 soil fertility saepling points
00' 3 root occupancy saepling points

4: acacia [Z]: crop

O 8 teak

O """—‘ : F—O—fi a: —1'O
’1 “ :
4
O i O: o e; O
t/ / z
. 0 a
t
0 i II 30.0 o e: O
t 1
11V ‘0“ t
O + 0 ‘+
+ 0° ‘ Q
.1 4
t t
l-—-'4
la
Figure 3.5 Sampling points in a plot

 

36

3.3.1. Teakgrosvthparameters

Measurements were carried out on a sample tree in
each plot which was randomly selected among three teak
seedlings located in the middle of the center row. Stem
height and diameter were measured bi-weekly until the crop
harvest time, and at 16 months after planting. Leaf
surface area was measured at the end of the first crop
growing season and also at 16 months after planting.
Height was measured from the soil surface to the end of an
unopened young leaf using a ruler. Stem diameter was
measured at the soil surface using a caliper.

Leaf surface area was measured by removing leaves
from each tree, photocopying them, and measuring the
images with a leaf area meter. Leaf surface area of the 16
month-old-teak was determined indirectly using a linear
regression equation:

Y = -34.90 + 0.898X = 0.965
where Y= leaf area ( in sq. cm ) and X= length times width.
( in sq. cm ). Leaf length was measured along the midrib,
while width was measured perpendicular to the midrib
between two points projected at the widest margin of the
blade. The equation was calculated using data obtained
from measuring 100 leaves obtained from an older stand of
teak. Leaf blades were photocopied and then areas

determined as above. If leaves were too large, they were

37

cut into smaller portions. A linear regression analysis
was selected to fit leaf area as a function of length
times width because a linear regression model is simpler
and adequately fit the need. Wargo ( 1978 ), working
with leaves of black oak, white oak and sugar maple, and
Manivel and Weaver (1974 ) working with "grenache"
grape leaves, successfully used a linear model to predict
leaf area.

Biomass measurement was accomplished by removing
the whole plants from the soil. The soil around the stem
of each plant was saturated with water so that the roots
were easier to pull from the soil. Leaves were removed,
stems were cut at the soil surface, and roots were
separated from the soil by manually washing them with
flowing water. All the plant parts were then oven dried

at 75°C for four days, and then weighed.

3 . 3 . 2 Crop parameters

Three 1 x 1 m.sq. plots were randomly established
within each experimental plot. The crops were harvested
from each plot and sundried for a week following the local
practice. The dried unhusked rice, grained maize and
peanut seeds then were weighed. The moisture content of
seeds was measured using a seedbury digital moisture
meter. These values of seed moisture content represented

the " moisture content at harvest time " for further

38

yield calculation. The yield of crop per hectare was

calculated following a formula of Zandstra _§ _;

( 1981 ),

yield ( kg/ha ) = yieldiplot (g ) 10,000 m2 loo-Mg
100 g plot area MCS

where MC = moisture content at harvest time :
MCS = standard moisture content i.e. 85%, 85%, and

88% for rice, maize and peanut respectively.

The influence of neighboring plant on crop yield
was observed by measuring the yield in three positions,
i.e. next to the teak row, next to the acacia row, and
within the crop rows.

Crop residues were harvested from each plot. The
" crop residue " of the pure teak plots was represented by
the above ground part of the existing weeds. The residues

were expressed in g fresh weight.

3 . 3 . 5 Acacia biomass

The biomass of acacia was measured by sampling the
row of acacia within each plot. The sampling unit was 25
cm in length. Within each row of acacia, three sample
units were randomly determined, then the acacia was

harvested after the soil was soaked with water, separated

39

into stem, leaf and root components, oven dried, and

weighed.

3.3.4 Rootoocupancy

Root occupancy was measured in terms of g dry
weight per sq.cm of soil. This was done by taking the soil
from two depth levels, 0-15 cm and 15-30 cm, at three
different distances, i.e 12.5 cm, 62.5 cm and 112.5 cm
away from the teak ( Figure 3.5 ). At each distance three
sampling spots were randomly placed along a circumference
with the corresponding distance as its radius, soils were
sampled using a probe 2.5 cm in diameter and composited
to represent the particular distance.

Soil was separated from roots by placing them into
a fine sieve and manually shaking the sieve under running

water. The roots were then ovendried and weighed.

3 . 3 . 3 . Soil fertility measurement.

Changes in soil fertility were measured at two
depth levels ( 0-15 cm and 15-30 cm ) by comparing the
nutrient contents before and after crop harvest. Soil was
observed on the whole plot basis and on the basis of
soil position relative to the covering vegetation.
While the " on the whole plot basis " soil measurement
embraced all of the 24 plots, the "position basis" soil

measurement was limited only to plots containing acacia.

 

40

Relative to the vegetation cover, soil was further
grouped into three categories, i.e soil of the teak-crop
interface, soil of the crop-acacia interface, and soil of
the crop-crop interface. For each of the soil positions
mentioned, a representative sample was obtained by com-
positing soils taken from three randomly chosen spots
( Figure 3.5 ).

The soil sample of each whole plot was a composite
of soils taken from six to nine spots depending on whether
the plot contained acacia. The spot locations were
randomly selected throughout the plot by considering the
position of soil relative to its vegetation covers.

Soils were analyzed for total N and total P using
the semi-micro Kjehldal technique: the exchangeable K,
Ca, Mg, and Na by extraction with 1 N NH4O AC using
absorption photometry ( Heald, 1965 ): pH using a glass

electrode assembly, and organic carbon according to the

Walkey-Black ( Potassium dichromate ) method.

3 . 4 Statistical analysis.
The statistical analysis of the main data was
carried out by the following analysis of variance ( Little

and Hills, 1978 ):

411

Number of blocks : B = 3
Factor treatments:
Main factors : L = Acacia ( 2 levels )

sub factors : C = Crops ( 4 levels )

Table 3.2 An analysis of variance table of a split
plot design.

 

Source of variation Degrees of freedoa

 

lain plot
Total LB-l
llocks 8-1
Acacia L-l
Error1a1 18-111L-11

 

Sub Plots
Total LC8-1

Crops C-l
Acacia x Crops 1L-111C-11

Error (bl 18-111C-llt18-ll1L'II1C-ll

 

The root occupancy data was analyzed following
the split-split plot analysis, where crop was the
main treatment, distance the sub-plot, and depth as the
sub- sub plot. The soil data, either from the whole plot
basis or from the position basis, was analyzed following
the split split plot design with main factor, sub and sub-
sub factors given in Table 3.3. All data were analyzed
using the MSTAT statistical program, and the means

comparison using the Duncan Multiple Range (D), which was

4&2

calculated as D = R(LSD) where R is a tabular value for
degrees of freedom for error, level of significance, and
distance of two means in an array of treatment means
( Little and Hills, 1978 ). LSD is the least significant
difference. In tables showing comparison of means, only

the LSD values, are to be attached.

Table 3.3 Treataent factors observed in the soil
data analysis.

 

whole plot Soil position
basis basis

Hain factor tiae tiae
Sub factor depth depth
Sub-sub factor acacia distance
Sub-sub-sub factor crop crop

 

Table 3.4 presents the kind of data collected and

the way they were analyzed.

43

 

 

 

T‘abel 3.4. ripe of data. factors observed and statistical procedures
Type of No. plots 14o. Factors Statistical.
of
data llith liithout sanples observed procedures
acacia acacia
I’ealc paraeaeters ( height. 12 12 21 - acacia Split plot
dia.. bionass. leaf area) - crops
Crop gield
-Plot basis 3 3 6 - acacia RCBD I
-Roaa basis 3 - 9 - roaa position 31280 H
Crop residues C including 3 3 3 - -
aaeeds
acacia 12 - 12 - crops R880 l
Root occupancy 12 - 72 - distance
frost teal: Split-
- soil depths split plot
- crops
Soil paraneters
- Plot basis 12 12 SS - tine Split-split-
- depth split plot
- acacia
" m
- Distance frost 12 - 1‘11 - tine Split-split-
teak basis - depth split-plot
- distance
- crops

 

ac'Randonised Conplete Block Design

14 . IREISIHLJHS

4 . 1 Effect of tumpangsari on teak.

The effects of tumpangsari on teak growth and
development were examined during its first four-month
period of growth ( during the first agricultural cropping
season ) and during its 12-16 month period of growth
( during the second agricultural cropping season ).

At the end of first agricultural cropping season,
the height of teak seedlings ranged from 6.3 cm to 11.5
cm., while at 16 months after planting it ranged from

32.6 cm. to 199.6 cm ( Table 4.1 ).

Table 4.1 Height, diaaeter and leaf area of teak grown with
and without various crops aeasured four and 16
aonths after planting.

 

at 4 aonths at 16 aonths
ht. dia. leaf area ht. dia. leaf area
(cal (aal (sq.cal (ca1 (aal (sq.cal

Hith acacia interplant
Teak wl corn 7.6 3 6 154 76.4 26.8 12,681
Teak w/ rice 11.5 6.1 619 199.9 50.9 13,995
Teak w/ peanut 8.2 4.6 398 163.5 49.4 18,629
Teak wlo crop 7.6 4 4 273 32.6 16.1 2,809

without acacia interplant

Teak w/ corn 6.5 4.1 269 69.7 22.7 7,604
Teak w/ rice 10.7 5.5 562 89.5 26.0 8,098
Teak w/ peanut 11.0 5.4 416 141.6 43.7 12,504
Teak wlo crop 6.3 4.1 282 38.2 15.7 3,181

 

44

455

Each of the teak parameters mentioned in Table 4.1
was signfificantly affected only by the types of crop. The
acacia factor and its interaction with crop had no

significant influence. ( Table 4.2 )-

Table 4.2 F values and their associated probability values 1 P 1 of intercropping
variables influencing height 1 Ht.1, diaaeter 1 01a. 1 and leaf area
of teak four and 16 aonths after planting.

 

Source of at 4 aonths at 16 aonths
variation 0F

 

 

Ht. Dia. Leaf area Ht. Dia. Leaf area
F P F P F P F P F P F P

 

Acacia (a1 1 0.01 -- 2.48 - 0.34 - 0.63 - 0.47 - 5.44 .144
(nsl 1nsl 1nsl 1ns1 (nsl 1ns1

Crops (bl 3 3.96 .035 8.03 .003 3.28 .058 8.70 .002 6.49 .007 4.26 .028
(41 1411 (*1 (ill 1’41 (*1

Ac. x cro. 3 0.88 -- 1.06 - 0.25 - 1.87 - 0.99 - 0.37 -
(nsl (n51 1nsl 1nsl (nsl ins)

 

4 . 1 . 1 . Height of teak 4 months after planting.

Teak in association with rice (TR ) grew better
in height than when grown alone ( T ) or with peanut
( TP ) or corn ( TC ). The average height of teak under TR
conditions was about 1.6, 1.7, and 1.2 times taller
than under T, TC, and TP conditions, respectively.

Biweekly observations on the growth of teak during

its first 4-month period are presented in Figure 4.1. Up

46

to six weeks after planting, teak showed no difference in
its height regardless the kind of crop it was associated
with. However beginning at week six, teak grown under TR
and TP conditions grew faster than when grown under TC
and T conditions. The slope of the height-growth line
of teak under TC visibly declined after six weeks which was
about the time corn entered its reproductive stage.

Similar phenomena were shown by teak grown under TP

conditions: a flatter slope of the height-growth line
occurred after week eight, i.e. about a week after peanuts
entered their flowering stage. Teak grown under TR
condition showed no apparent reduction of height growth
related to the stages of growth of rice. Teak grown under
T condition were generally shorter, at any point of time,

than when grown in association with crops.

47

 

 

 

 

12 n
-‘- TEAK WI CORN -E- TEAK WI RICE _
* TEAK WI PEANUT 9(- TEAK W/O CROP
10 "
f/x
/'
a -
H -
E _ I/
a. .-
H '7 j
T
(CM) ‘ _
/
_;/
zfgfifij;
o l I i l l L
2 4 6 8 10 12 14 16
WEEKS
Figure 4.1

Height growth curve of teak in
association with crops during the
first four months of plantation

A comparison of
influenced by crops is
4.2. Teak grown with
when grown with corn or
with peanut. In terms

are the preffered first

413

average heights of teak as it was
presented in Table 4.3 and Figure
rice was significantly taller than
without a crop but not when grown
of teak growth, rice and peanut

rotation companion crops.

Table 4.3 Coaparison of aean values of height, diaaeter
and leaf area of teak grown with and without
crop four and 16 aonths after planting.
heans followed by the saae letter are not
significantly different.

 

Cropping
coabination

paraaeters observed

 

Height Diaaeter Leaf area
1 ca 1 1 as 1 1 sq. ca 1

 

four aonths

 

 

Teak w/ corn 7.10 a 3.87 a 211.680 a
Teak w/ rice 11.15 b 5.82 c 590.954 c
Teak w/ peanut 9.63 ab 5.07 bc 407.348 abc
Teak wlo crop 7.10 a 4.28 ab 278.080 ab
LSD .05 = 3.13 0.93 284.467

Teak w/ corn
Teak w/ rice
Teak w/ peanut
Teak wlo crop

16 aonths

 

73.05 a 24.88 ab 10,143.36 ab
144.77 b 38.33 bc 11,046.82 5
152.57 b 46.40 c 15,567.22 0

35.46 a 15.78 a 2,995.48 a

 

LSD .05 =

59.24 16.59 7,767.86

49

 

d

Height of teak in association with
crops four months after planting

 

 

Figure 4.2

 

50

4 . 1 . 2 Height of teak 16 months after planting.

Measured at 16 months after planting the height of
teak ranged from 32.6 cm under T condition to 199.6 cm
under TP condition ( Table 4.1 ). Teak grown with peanut
( TP ) grew taller than the others. Although it was not
significantly taller than the teak grown with rice ( TR ),
but significantly taller than when grown with corn ( TC )
or without a crop ( T ) as shown in Table 4.3 and Figure
4.3. Teak under TR and TP conditions grew faster in
height than under TC and T conditions in the last 12
months after the first measurement. After two cropping
seasons, rice and peanut have shown their consistent
position as promising companion crops for teak.

Teak grown under TR conditions with the acacia was
much taller than when grown under TR' but without the
acacia ( Table 4.1 ). It was an interesting case since
this phenomenon did not occur on teak grown with other
crops. Further analysis on the data obtained from the
teak-rice ( TR ) combination were conducted. By assuming
that the TR was subjected to acacia treatment with three
replications, it was found that the acacia effect was

significant on height ( Table 4.4 ).

551

 

 

12583

                       
   
 

/

   
 

/
/?
W? W .

    

{f/

/

...

W

  

  
 

I

       

w 0

Height of tank in association with

crops 18 months after planting-»

4.13

IFilnarwe

factor as it influenced height,

diaaeter and leaf area of teak grown with rice

eeasured at 16 aonths after planting.

Table 4.4 F values and associated probabilities 1 P 1 for
the acacia

 

Paraeeters eeasured

 

Factor
observed

Leaf area

Diaaeter

Height

 

9.00 0.095 6.57 0.124

38.51 0.024

Acacia

1ns1

1ns1

141

 

52

4 . 1 . 3 Diameter of teak 4 months alter planting.

Diameter growth of teak showed similar trends to
that of height. Teak grown in association with rice ( TR )
grew more in diameter than that in association with corn
( TC ), peanut ( TP ), or without a crop ( T ). The mean
diameter at the end of the first crop growing season
ranged from 3.6 mm under TC to 6.1 mm under TR
( Table 4.1 ).

Without a crop association (T ), which is actually
under weed competition, teak continuously grew slower than
with crops. The rates of diameter growth of teak under TP
and TR conditions were about equal up to week 10. However,
in the later stages teak under TR grew faster than that
under TP. Teak grown under TC showed a declining diameter
growth rate after week eight, which was commensurate with
the time of corn flowering ( Figure 4.4 ). Similarly to
the case of height growth, the acacia factor had no
significant effect on diameter growth of teak (P: .255)
whereas the crop factor did have a significant effect ( P=
003 ) ( Table 4.2 ). Further analyses of the effect of
crops on diameter growth of teak showed that diameter of
teak grown under TR was significantly greater than that of
teak grown with other companions except peanut ( Table
4.3 ). The effect of crops on the diameter of teak four

months after planting is displayed in Figure 4.5.

53

9585.3 unaua unaccu— uaou enono seduce—amp 0:» «0 acacoa anon aean.

 

 

 

3 no a non-d c on o no and one Inf—:6 nacho $.53 nanoseconds
c: “a a a s a. u 0 can 0.53... cm see» no 0:30 5930.; unease:—
. . v... 0.5:..—
9.33
9 3 up 9 m o e m
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« \, m
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2?:
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m m . E
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m - 0.» h.
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0
s
h coco 93 via.— nx-hazfia ‘3 x5.— ..i. . od
. u 00:. x? in... all 2:00 ‘3 v20... II
o . .

 

 

 

 

 

54

4 . 1 . 4 Diameter of teak 16 months after planting

The results of diameter measurements at 16 months
after planting are shown in Table 4.1. The largest dia-
meter ( 50.9 mm ) was observed from teak grown in plots
with acacia under TR condition, while the lowest was found
in teak without crops ( T ). Again the acacia had no sign-
ificant influence on the diameter growth of teak ( Table
4.2 ), but the effect of crops was significant ( P=
0 . 007 ) .

Further comparison among diameter means of teak as
influenced by the types of crop ( Table 4.3 and Figure
4.6 ) indicates that teak grown with peanut ( TP )
performed best, i.e. peanut was the best companion crop
for teak. By contrast, corn was found to be comparable to
weeds ( T ).

Among teak plants under TR condition diameter was
much bigger in plots containing acacia than in plots
without acacia. However, unlike the case with height, a
statistical analyses of this phenomenon ( Table 4.4 ),
indicated that the acacia had no significant effect

( P = 0.095 ) on the diameter growth of teak.

55

 

 

led .05

 

 

 

 

 

 

 

 

 

 

 

 

 

60

50'

.
O.
4

nUlZflMChICRH

(mm: 20 -

wlrlce wl peemt wlo crop

w/cun

.6
Diameter of teak

Figure 4

th

10D W1

t

in assoc1a

crops 16 months after planting

56

4 . 1 . 5 Leaf area of teak 4 months after planting

The average number of leaves per teak seedling at
four months was nine to 11. Leaf area ranged from 154
sq.cm under TC with acacia, to 619 sq.cm under TR also in
a plot with acacia ( Table 4.1 ). As was the case with
height or diameter, crops were found to be the only factor
which significantly influenced the leaf area of teak
(P= 0.058, Table 4.2 ). Figure 4.7 displays how the leaf
area of teak was influenced by the kind of crops four

months after planting.

4 . 1 . 6 Leaf area of teak 16 months after planting

The number of leaves at 16 months after planting
ranged from nine to 15 per seedling, with leaf area about
10 to 80 times larger than what was measured at four
months. The smallest leaf area was measured in teak grown
alone ( T ) ( 2809 sq.cm ), while the largest was with
rice (TR ) within plots containing acacia ( 18,629 sq.cm )
( Table 4.1 ). The acacia factor was not significant
(P=0.144), only the crop factor showed a significant
effect on leaf area growth ( P=0.028) ( Table 4.2 ). A
comparison of leaf area of teak as it was influenced by
crops at 16 months is displayed in Figure 4.8. Teak
under TP had the largest leaf area followed by teak
grown under TR , although the difference between them was

not significant ( Table 4.3 ).

Thomumdaeqonr

57

 

 

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441.1(0. (C141(

40"”

wlpumm

of teak in association with

months after planting

Leaf area
crops 18

Figure 4.8

Loaf area of teak in association with

crops four months after planting

Figure 4.7

 

513

4 . 1 . 7 Dry weight production.

The measurement of dry weight of teak was done four
months after planting. Root dry weights ranged from 0.79
g, in teak grown with corn in plots w/ acacia to 3.57 g
in teak grown with rice in plots without acacia. Stem
dry weight ranged from 0.53 g in teak grown with corn
without acacia to 1.21 g in teak grown with rice also in
plots without acacia. Leaf dry weight ranged from 1.94 g
in teak without a crop association nor acacia to 5.36 g
in teak with rice but without acacia. The result of

measurements is displayed in Table 4.5

Table 4.5 Bio-ass allocation of 4-eontn-old teak seedlings
grown either alone or under tuapangsari.

 

Cropping Oven-dry bio-ass (q)

 

coebination Root Stee Leaf Total

 

Hith acacia interplant

 

Teak ul corn 0.79 0.58 2.00 3.37
Teak a] rice 3.41 1.19 4.92 9.52
Teal u/ peanut 1.99 1.85 3.62 7.46
Teak ulo crop 1.36 0.57 1.94 3.87
Hithout acacia interplant
Teak ul corn 0.97 0.53 2.51 4.01
Teak ul rice 3.57 1.21 5.36 10.14
Teak u/ peanut 2.14 1.04 4.09 7.27
Teak u/o crop 1.07 0.55 2.51 4.13

 

59

Similar to its effect on diameter, height, and leaf
area, the acacia did not significantly affect biomass
of teak and only the crop factor had a significant effect
on the biomass. ( Table 4.6 ).

Comparison of mean values of biomass parameters
as they were influenced by the type of crops is given in.
Table 4.7. While the allocation of biomass of teak
seedling as it was influenced by crOps four months after

planting is presented in Figure 4.9.

 

 

3"- nus-u-

 

mots 804%
one s

 

Figure 4.9
biomass allocation of teak in associat-
ion with crops four months after planting

61)

Table 4.6 F - values and associated probabilities of variables as they
influenced the bioeass paraaeters of teak .

 

Biooass paraaeters

 

Source of BF Root Stees Leaves Total bioeass
variation F P F P F P F P
Acacia (al 1 0.17 ns 0.11 ns 1.485 ns 3.50 0.202 ns
Crops lb) 3 23.87 0.0 *4 15.0 0.0 44 11.819 0.003 If 13.59 0.0 if
Leg.x Crops. 3 0.22 ns 0.46 ns 0.002 ns 0.02 ns

 

Table 4.7 Cosparison of the wean values for root ,stee, leaf
and total bioeass paraaeters of teak at four aonths
grown with crops 1 eeans followed by the sase letter
are not significantly different 1.

 

bioeass paraaeters 1 g dwt )

 

 

Root Stee Leaves Total bioeass
Teak w/ corn 0.89 a 0.55 a 2.26 a 3.67a
Teak w/ rice 3.49 c 1.20 c 5.14 b 9.83c
Teak wl peanut 2.07 b 0.95 b 3.85ab 6.86b
Teak w/o crop 1.22 ab 0.56 a 2.22 a 4.41a

 

LSD .05 1.31 0.40 2.39 4.04

621

4.2 Elfectsoncrops

4.2.1 Cropylelds
The yields of crops were observed either. on
whole plot basis or a row basis. While the first
intended to measure the crop yield per ha, the later

intended to determine if the yield of a crop in a row

the
was
was

was

influenced by its position, e.g. against teak, the acacia,

or itself. Yields of crops per ha are shown in Table 4.8.

Table 4.8 Yield of crops obtained fros a teak -tuepangsari
plantation at first and second year of cropping

 

Cropping Crop Yield 1 Kg ha“ 1

 

coabination harvested first second
cropping cropping

 

lith acacia interplant

Teak w/ corn corn 1058.9 878.5
Teak w/ rice rice 1032.3 976.3
Teak w/ peanut peanut 679.5 755.6

Teak w/o crop -- -- --

Hithout acacia interplant

Teak w/ corn corn 712.9 758.8
Teak w/ rice rice 1058.1 985.1
Teak w/ peanut peanut 979.1 814.6

Teak wlo crop -- -- --

 

(52

Data were analyzed following a Randomized Complete Block
Design ( RCBD ) procedure as if each crop was treated by
planting it with and without acacia with three replicat-
ions. The analysis showed that there was no significant
effect of the acacia on the yield per ha of crops. (Table

4.9)

Table 4.9 F - values and the associated probabilities of the
acacia as it influenced the yield of crops

 

crops

 

Source Rice Corn Peanut
of -------------------------
Variation DF F P F P F P

 

Acacia 1 1.47 0.349 1.41 0.357 0.51 ---
(nsl (nsl (nsl

 

The non-significant effect of acacia on the yield of crops
on a plot basis was was expected knowing the positions of
the acacia rows: the 1 sq.m. subplot for harvesting crops,
and the age of the plantation itself. However, without
holding the level of alpha of 0.05 as the limit of
significance, the results show that the effect of the
acacia on peanut had much smaller influence on peanut
yield compared to that on rice or corn. This could
be intepreted as a sign of different degree of responsive-
ness between peanut on one hand and rice and corn on the

other. The crop yield data that there was no significant

623

difference between the yield of crop of the first year’s
of cropping season from that of the second year. ( Table

4.10 )

Table 4.10 F-ratio testing group variances 1 F l and the associated
probabilities 1 P l of the crop yields.

 

crop yield of

 

Source of variation Corn Rice Peanut

 

FPFPFP

 

Year of harvest 1.18 0.429 1.16 0.462 1.13 0.34
(nsl (nsl (nsl

 

Observation on the yield of crop related to the row
positions ( Table 4.11 ) indicated that the position of
the crop row'had a significant influence on yield. For
most crops, the closer the row to acacia the greater the
yield, although the differences in yield between rows
closer to the acacia and the two other positions were not
always significant ( Table 4.12 ). In general crops
responded positively to the immediate presence of the
acacia. however, there was no consistent pattern found in
the yield of a crop with regard to its closeness to the

acacia.

 

644

Table 4.11 F - values and associated probabilities of the row
position factor as it influenced crop yields obtained
froe the tuapangsari plantation with acacia inter-
planted four aonths after planting

 

Source of C r o p 5
Variation 0F Rice Corn Peanut

 

Row position 2 11.13 .023 6.43 .05 8.04 .039
(ll 1*) (fl

 

In the cases of rice or peanut, the yield was significant-
ly greater in the row close to acacia. However, this was
not the case for corn. The greatest yield of corn was, in
fact, obtained from the row adjacent to teak ( Table
4.12 ).

The lowest yields of rice or peanut were measured
in the row adjacent to teak, but in the case of corn the

lowest yield was obtained from the within-crop row.

Table 4.12 Yield of crops on the row to row basis. The
saee letters following a eean indicates no
significant difference.

 

 

Row of crop Yield 1 g e.row " 1

adjacent to Rice Peanut Corn
Acacia row 24.61 a 16.36 a 38.09 a
Other crop row 22.13 ab 13.45 ab 32.91 b
Teak 18.88 b 10.97 b 43 00 ab

 

158 .05 4.22 3.73 3.38

655

4 . 2 . 2 Crop residues and weeds

Most of the agricultural crop residues after
harvest were taken and used for animal feed. The yield of
residues measured at the first cropping season of this

1.

experiment ranged from 6.8 ton ha- of rice straw to

1 of corn stalks Table 4.13 )

11.13 ton ha-

Weeds occupied the empty area among teaks planted
without crops. The average fresh weight of weeds measured
from this system was about 4.6 ton ha-l, consisting mainly

of seven species listed in Table 4.14.

Table 4.13 Crop residue 1 fresh weight 1 free a teak
tuspangsari plantation.

 

Cropping coebination residues ton ha"

 

Hith acacia interplant

 

Teak w/ corn corn stover 10.3
Teak w/ rice rice straw 8.9
Teak w/ peanut peanut stalk 7.5
Teak wlo crop weeds 4.4
kithout acacia interplant
Teak w/ corn corn stover 11.1
Teak w/ rice rice straw 7.2
Teak w/ peanut peanut stalk 6.8
Teak w/o crop weeds 4.7

 

615

Table 4.14 hain weeds found in the Teak - wlo
crop plots and their percentage of
total fresh weight

 

 

 

 

 

 

 

Heeds 2 of total
Hedusan 1 Aggratue conyzoides l 6.45
Katesas 1 Boreria lanceolata 1 42.1
Uedungan1 Panicue oaxieue l 8.73
Kirinyu 1 Egppthoriue pubescens l 2.91
llalang 1 leperata cylindrica l 1.90
Rondoeopol (Coo-elina 2p; 1 13.86

Ri rendet (Hieosa pudica l 1.70
Others 22.32

 

4.3 Acsdsblomass

The acacia was planted in rows between two rows of
teak. In plots where teak was associated with crops,
acacia row laid between two rows of crop, while in plots
where teak was grown without a crop, the acacia row was
surrounded by weeds. The average diameter and height of
the acacia were 8.5 mm and 54 cm, respectively. Total
biomass of acacia per meter row as it was influenced by

neighboring vegetation is shown in Table 4.15.

Table 4.15 Bioeass of acacia as influenced
by the neighboring vegetation

 

Neighboring total bioeas
vegetation 1 g.e‘2 l
Heeds 94.7
Rice 157.1
Corn 132.8
Peanut 152.9

67

The available data of acacia biomass were analyzed
using the RCBD ( Randomized Complete Block Design )
procedure as if the acacia was treated with different
sourrounding plants ( rice, corn, peanut or weeds )
The effects of surrounding plants on the biomass of the
acacia was not significant. This is an important character-
istic for a plant intended to be a nurse crop for other

plants.

4 . 4 Root occupancy
Root occupancy of the plantation was observed on the
basis of distances from the teak at two different depth
levels. There were three different distances from teak
observed ; i.e. A = 0 -12.50 cm, B = 12.50 - 62.50 cm, and
C = 62.50 - 112.50 cm, which represent the soils between
teak and crop, between crop rows( soil under the crop ),
and between crop and acacia, respectively.
Data analysis shown in Table 4.16 indicates that
cropping combination, distance from teak and their inter-

action have a significant effect on soil root occupancy.

158

Table 4.16 Analysis of variance of root occupancy in the
soil in respect to teak cropping coebination,
distance froe teak, and soil depth.

Source of DE Sue of Hean F Prob

variance squares square

 

127.37 63.686 0.46
2046.65 682.217 4.94 0.046 4
Error 1a 1 827.87 137.979
Distances 534.40 267.302 4.39 0.030 4

Replication 2
3
6
2
Crops x Dist. 6 1370.24 217.874 3.58 0.019 s
6
1
3
2
6

Crops

Error (bl 1 973.26 60.829

Depth 71.84 71.840 1.01 0.324 ns

Crops : Depth 638.91 179.637 2.52 0.081 ns

Dist. x Depth 260.11 130.057 1.83 0.182 ns

Crops x Dist.x 818.75 136.458 1.92 0.118 ns
Depth

Error 1 c) 24 1707.49 71.145

 

How roots of the teak- crop combinations occupied
the soil in relation to the distance from the teak is
presented in Table 4.17. In the case of teak alone, or
with peanut, the difference of root occupancy of the soil
between teak and crop and the soil under crop was not
significant. For both cropping combinations the root
occupancy of the soil laid between crop and acacia was
significantly less extensive than the other two positions,
whereas unnder the teak-rice or teak-corn conditions, the
greatest root occupancy was under the crop itself. This
fact may be explained by the fact that both corn and rice
are are members of the grasses family, Graminea. Rice is
characterized by a compact, fibrous rooting system tend to

develop horizontally rather than vertically ( Grist, 1986)

(99

It was also reported by IRRI in 1979, that rice roots are

relatively shallow, and in upland rice 40-60% of root

weight found in the top 20 cm of soil ( Norman et al,

1984 ). The soil root occupation of teak-rice cropping was

the most extensive than the other teak-crop combination

being studied and the difference was significant ( Table

4.13 ).

Table 4.17 Heans soil root occupancy of teak-crop
coebination at three different distances
froe teak. The saee letter following a
value indicates no significant differ-

 

 

 

ence.

Distances Cropping coebination

froe

teak Teak Teak Teak Teak
1 ce ) w/ rice w/corn w/ peanut wlo crop

root occupancy 1 g r3 l

A 1 0-12.5 1 23.8 a 17.4 a 25 8 a 28.1 a
8 1 12.5-62.5 1 44.4 b 24.6 b 23.1 a 24.3 a
C 1 62.5~112.S T 34.5 c 19.6 a 17.3 b 20.6 b

 

LSD .05= 4.89

Table 4.18 Hean root occupancy of soil under
teak- crop coabinations. The saee
letter following a aean indicates
no significant difference .

 

Cropping coebination root occupancy

 

1 g.e"l
Teak w/ rice 32.224 a
Teak w/ corn 20.532 0
Teak w/ peanut 22.064 5
Teak w/o crop 24.274 ab

 

LSD .05 = 9.58

71)

4 . 5 Effects on soil fertility.

One of the study objectives is to determine the
effect of tumpangsari on soil fertility as for many years
it has been feared that cropping may induce negative
effect on soil fertility especially in industrial forest
plantation.

The chemical properties of the soil of the
experimental site at the beginning of the study are shown
in Table 4.19. The site which had previously been under a
stand of nelaleuca leucadendron, was a rather good site
with medium level of organic matter and nitrogen. The C/N
ratio of nearly 12 indicates satisfactory mineralization
( Young, 1976 ). Soil pH was within a desirable range
( 5.00-7.00 ) for both nutritional and biological

aspects ( Wilde 1958 ).

Table 4.19 Soee characteristics of surface 10-15 cal,
and subsurface 115-30 cel soil at the
initiation of the trial.

 

 

 

Depth of soil
Soil

surface subsurface
properties 10-15 cal 115-30 cal
Total N (ppel 2076 1428
Total P (ppel 544 431
pH 6.5 6.6
C - organic 111 2.4 1.7
C/N ratio 11.6 11.9
K (ppel 70 52
Ca (ppel 3034 2788
Na (ppel 66 75

Hg (ppel 346 310

71
As it was explained earlier in chapter 3, the
analysis of soil has been attempted on two basis, i.e in
term of whole plot ( plot basis ) and in term of vegetat-

ion cover ( distance from teak basis ).

4 . 5 . 1 Effects on soil nitrogen and carbon

At the initiation of the trial the total nitrogen
concentration of in the surface soil ( 0 - 15 cm depth )
and subsurface soil ( 15 - 30 cm depth ) ranged from 1961
to 2151 ppm, and 1794 to 2057 ppm. At the first crop
harvest, the ranges were 1286 to 1615 ppm in the 0 - 15
cm depth, and 1553 to 1906 in the 15 - 30 cm depth ( Table
4.20 ). The surface soil contained more nitrogen than
the subsurface soil. Table 4.21 presents the F values of
various factors influencing the chemical characteristics

of the soil and interactions among them.

72_

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74

Four months after planting, the nitrogen concentra-
tion of the surface soil dropped from 2075 ppm to 1901
ppm. This is significant ( Table 4.22 ) and might due
to activities involving planting of crops and teak which
lead to leaching of nitrogen and organic matter to the
subsurface soil. A significant increase in nitrogen and
organic carbon in the subsurface soil from 1430 ppm to
1713 ppm supported this. The increase, however can also be
attributed to the root development of crops and acacia
beyond the 0-15 cm depth as the interaction between
acacia and crops is significant at P= 0.042 ( Table
4.22 ) The significant increase in organic carbon from 1.7
% to 2% might due to the increase of root biomass of crops
and acacia reported earlier ( Table 4.15 )

The soil N (also P) concentration was also invest-
igated at distances of 12.5 cm, 62.5 cm and 112.5 cm away
frow teak, representing soils between teak and crops,
under crops, and between crops and acacia, respectively.
and it was found that the distance factor had no signifi-

cant effect ( Appendix A and B ).

715

Table 4.22 F values and associated probabilities of soee variables
influencing N, P, and organic carbon concentrations
of surface 1 0-15 ce 1 and subsurface 1 15-30 ca 1 soil
four eonth after planting.

 

Source of N P C

variance F P F P F P

 

surface soil 1 0-15 ca 1

Tiee 1al 1 18.09 0.051 4 - - 0.56 -
Acacia (bl 1 2.50 0.188 ns 0.35 - 0.49 -
Tiee x acacia l 0.51 - 9.07 0.039 I 0.12 -
Crops 1c) 3 0.47 - 5.39 0.005 f! 3.50 0.03 f
Tiee x crop 3 0.41 - 4.80 0.009 ii 0.68 -
Acacia x crop 3 0.48 - 1.26 0.310 0.56 -
Tiee x acacia s crop 3 0.49 - 0.02 - 0.19 -

 

v

subsurface soil 1 15-30 ca

Tiee 1a) 1 59.79 0.016 If - - 43.04 0.022 f
Acacia 151 1 1.28 0.320 ns 10.1 0.033 f 0.33 -
Tiee x acacia 1 0.02 - 13.85 0.020 f 0.13 -
Crops 1c) 3 1.90 0.156 ns 8.05 0.000 4* 0.05 -
Tiee x crop 3 0.37 - 2.24 0.109 ns 0.90 -
Acacia x crop 3 3.18 0.042 I 2.45 0.088 ns 0.16 -
Tiee x acacia x crop 3 1.2 0.303 ns 1.83 0.169 ns 1.02 0.402 n5

 

4 . 5 . 2 Effects on soil phosporus
Phosporus concentration in the subsurface soil
increased significantly (P= 0.03) with the presence of
acacia. Crops also showed a significant effect on soil P
but only on plots with acacia as soil P increased from
425 ppm to 506 ppm right after the first harvest. The

interaction of crop and time was also significant

76

( P=0.039)( Table 22 ). As soil P in this case is total P,
it would be more interesting to look at the available
P in soil using extracable solution such as Bray-1 or
Bray-2. Ojeniyi gt g; ( 1980 ), in a study on effects of
agrisilviculture on soil chemical properties in Nigeria
indicated that interplanting of crops increased

( though insignificantly ) nitrogen and phosporus ( Bray-1
extractable ) in the top surface soil (to the depth of 12
cm). As these increases might reflect reduction and
degradation of soil organic matter 30 months after
planting it was not the case for soil in this study after
the first harvest of crops. The development of root
system of crops beyond the surface depth apparently was
the major contributor to the increase in soil organic C,

N, and P in the subsurface soil.

4 . 5 . 3 Effects on soil acidity and extractable bases

There was no signficant change in pH soil between
the time of trial initiation and the time of harvesting
the first crops. ( Table 4.21 ). Soil pH was not
influenced either by the kind of crop, depth of soil.

The concentration of extractable K, Ca, Mg, and
Na in the soil at the beginning of the trial were 61,
2911, 328, and 71 ppm while after crop harvest they were
53, 2712, 334 and 63 ppm, respectively ( Table 4.20b ).

The differences in extractable bases before the trial and

77

at first crop harvest ( four months after planting )
were generally not significant .

Magnesium, Na, and Ca concentrations of the plots
with acacia were generally lower than those of plots with-
out acacia, although the difference was not significant.
0n the contrary, the K concentration was significantly
influenced by acacia (P=0.019)( Table 4.21 ) as soil of
the plots with acacia contained more K than the ones
without acacia. Crops showed no significant influence
on extractable bases. Total exchangeable bases with
combine Mg, N, Ca and K showed no effect with time,
acacia or crops for both surface and subsurface soils.

The results agree with the study of Ojeniyi gt a;
( 1980 ) which showed no significant changes in soil total

exchangeable bases as result of agrisilviculture.

5 . DISCUSSION

In the first four months of its life, teak showed a
characteristic of allocating more biomass to the leaves
and roots ( Figure 4.9 ), which likely will change with
age. A study conducted on growth and nutrient requirements
of teak in Nigeria indicated that nutrient proportion
chanelled to foliage decreased while those to trunk and
branches increases with age. The distribution of all the
elements followed a similar trend and varied with stand
age. ( Nwoboshi, 1984 )

During the first 16 months of plantation, Acacia
yillgsg, the interplanted legume, has shown no significant
effect on teak ( Table 4.2 ) as well as on crops. During
the duration of the study, the acacia apparently did not
contribute as much as is usually expected from a N-fixing
species. A longer study on the role of acacia or other
interplanted legumes in tumpangsari system is needed to
see if this is a continues trend. Results of the present
study add evidence for a necessary reexamination of the
assumption underlying current nitrogen credit recommend-
ations for legumes in crop rotation as suggested by

Hesterman et.al ( 1987 ).

78

 

79

During 16 months of plantation the growth of teak
was significantly influenced by crops. Diameter and
especially height were growth parameters which showed
stronger response to the treatment than did the leaf
area ( Table 4.2 ). Up to six weeks after planting,
teak seedlings showed no difference in height growth no
matter with what was kind of crop it had been associated
( Figure 4.1 ). This may be an indication that up to this
point, the growth of seedlings still fully depended on the
reserve food stored within the seed, which was about the
same amounts ( fruits had been selected based on the same
size ). From then on, the growth of teak should reflect
the influence of treatment since the teak fruits had been
collected from a same seed stand.

Although it is logical to expect that a significant
difference in one kind of growth parameter will likely be
followed by a significant difference in another parameter
that is closely related ( such as among height, diameter
and leaf area ), the present study indicates otherwise. It
was observed in this study ( Table 4.3 ), that the
significant difference in height or diameter did not
always mean a significant difference in leaf area. It
was observed that after 16 months of plantation, the
significant difference in height was not accompanied by a
significant different in leaf area ( compare teak w/rice

or teak w/peanut v. teak w/corn ). It was a sign of poorer

80

performance in term of photosynthesis of the teak grown
with corn than when grown with rice or peanut. This
performance was likely due to the greater degree of
shading caused by corn foliage that those caused by rice
or peanut foliages.

Generally, teak grown with rice or peanut gave a
better performance compared with that grown with corn or
without a crop. It was evident that teak growing alone
without companion crops was inferior at the 4- and 16-
month period after planting than when grown with any of
the crops used in this experiment. These results are
contrary to the results of the study carried out by Coster
(1937) who concluded that crops actually had a negative
influence on the growth of teak after 3 years of plantat-
ion. The difference between this experiment from that of
Coster’s may stem from the difference in the duration
of the study and the facts that patch weeding, a common
practice for non tumpangsari plantations, was applied to
this experiment. Teak without crops was actually exposed
to weed interference. An investigation in Sudan indicated
that teak responded to clean weeding with higher survival
and better growth than when subjected to strip or patch-
weeding ( Annon.,l954 ). Results of a study carried out
by J.Combe and N.Gewa1d in 1979 ( cited by Budowski,
1983 ) indicated that the advantage of growing crops with

forest trees in taungya could be a complementary inter-

81

action. The study showed that at 2 x 3 m spacing, gmelina
planted alone after 15 months of plantation, was not
significantly better than when grown with crops, either
in diameter or in height.

By incorporating a crop into the teak plantation,
each hectare was able to produce, on the average, about
886 kg corn, 1045 kg rice or 829 kg peanut in the first
cropping season and about 818, 980, or 786 kg of corn,
peanut, rice, respectively in the second season ( Table
4.9 ). There was no indication of a great yield reduction
in the second cropping season. The differences in yields
of crOps between the first season and the second season
was not significant. The experimental site is located in
the climatically rather dry region of Java, and Nye and
Greenland ( 1960 ) had observed that the decline of yield
of the shifting cultivation in the drier region is slower
than that in the wetter zone.

An agrisilviculture study in southern Nigeria
interplanted young gmelina with corn, yam, and cassava,
( Ojeniyi et al., 1980 ) indicated that the practice
usually resulted in slight but insignificant increases in
soil N and P, a decrease in organic C, and no change in
exchangeable bases and pH compared with pure gmelina
stands. The study investigatied three ecological zones of
southern Nigeria and showed that cultivation or cropping

could result in reductions of C/N ration of surface soils:

82

Continuous cropping showed no effect as soil pH did not
fall below 5 on farm plots, and concluded that soil
fertility was not affected by interplanting of single or
multiple food crops with forest crops.

At the beginning of the study the surface soil
contained more nutrients ( N,P, organic C, Mg, K, Ca, Na )
than the subsurface soil. Concentrations of N, P, and
organic C in the surface soil decreased after four months
while those in the subsurface soil increased ( the time-
depth interaction was significant ). The accelerated
decomposition process of the humus during cropping and
further leaching by rainfall may be responsible for the
deposition of nutrients into the subsurface soil. If the
forest cover is cleared, the nitrification process becomes
more rapid because the exposure of surface organic
colloids is followed by a moisture-induced population
burst of nitrifying bacteria ( Birch, 1958 ). The nitrate
is then moved downward by rain to the lower horizon.
Jones (1975) worked with soil under corn in Nigeria and
estimated that the downward rate of nitrate movements was
about 0.2 to 0.3 cm per cm of rainfall. In another experi-
ment carried out by Wetselaar ( 1962 ) a downward nitrate
movement of 2.7 cm per cm of rainfall was observed.

Some phosporus may also be released during humus
mineralization. Phosphate ions may move downward during

the rain and be deposited on the subsurface soil,

83

although they are unlikely to be leached in significant
amounts beyond the top few inches ( Nye and Greenland,
1960 ). The fact that increased concentrations of organic
carbon in the sub-surface soil was accompanied by increas-
ed N and P concentrations was rather unusual. The increase
in soil N or P, especially in tropical soils, normally
reflects the reduction and degradation instead of the
increase of soil organic matter. Considering the nature of
the teak-crop plantation, this phenomenon could be due to
the root system development beyond the 15 cm depth and
a deposition of organic matter from the surface soil into
the subsurface soil. This deposition was caused either by
the activities of soil fauna or by farmers husbanding
their crops.

There was no significant change in total exchange-
able bases and acidity after the first cropping season.
Nye and Greenland ( 1960 ) also observed no considerable
decrease or increase in exchangeable bases in soils under
shifting cultivation. The soil reaction values ( pH )
between 5.00 to 7.00 had little influence on the choice
of plants to be planted ( Wilde, 1958 ), implying that
during this study crops were not growing under pH stress.

This study was aimed at the determination of suit-
able companion crops for teak in tumpangsari plantations.
Although the response of teak at four months and 16 months

after planting still followed a similar trend, further

84

observation on what happens afterwards is still needed.
Among the crops under investigation, corn was the least
positive companion crop of teak. However, it still is a
better alternative to grow teak with corn than letting the
area become covered by weeds. Corn should be planted after
rice so that teak has a chance to gain better growth
capital before it is exposed to a much stronger
competitor; teak grown with rice had about four and three
times greater root biomass and leaf area, respectively,
than that grown with corn. Effects of rice and peanut were
not significantly different so that as far as teak is
concerned, it does not matter which one is to be planted
first. However, because 1) the forest farmers usually
grow crops in sequence ( or at least in a relay
cropping system ), and 2) the first crop grown in the
sequence may affect the successful growth of the following
crop ( allelopathic effects ), rice should be grown first.
It was observed that the highest yield of rice was
obtained when it was planted after fallow than when
planted after soy bean ( Glycine max ), cowpea ( yigna
ugguiculata ), mungbean (Phaseolus ureus), or sorghum
(Sgrghum bicolor) ( Hamid et.al, 1982). It is reasonable,
then, to suggest the rice-peanut—corn sequence for a teak
tumpangsari plantation under the Wanagama I condition,
which is also one of the most common cropping patterns in

Indonesia (Birowo, 1975).

6 . SUMMARY AND CONCLUSION

Teak was grown in combination with rice, corn and
peanut in plots with or without a legume, following the
common practice of tumpangsari, on an oxisol soil in the
Wanagama I forest area. Teak grown without a crop, a
control treatment, was patch weeded while those grown
with crops were clean weeded as the farmers maintain
their agricultural crops.

Although the acacia factor was not statistically
significant, leaving behind the type of crop, teak grown
in the plots with acacia were on the average taller at
four months than when grown in the plot without acacia; a
similar situation was also found after 16 months.
Analysis of the individual effects of crop on height
growth of teak related to acacia at 16 months after
planting indicated that only teak grown with rice was
significantly effected by the acacia. The type of crop was
the only factor that significantly influenced the growth
of teak. Both at four or 16 months after planting, teak
grown with rice or peanut performed better than when grown

with corn or without a crop.

85

86

The yield of corn, rice, and peanut, in the first
cropping season was 886, 1045, and 829 kg.ha-1 , while in
the second cropping season yields were 818, 980, and 786
kg.ha-1, respectively. There was no significant differ-
ence between crops harvested from plots with acacia or
without acacia. The influence of acacia was significant
only on the yield of rice in the row adjacent to acacia,
but not on the yield of the other crops.

Crop residues constituted harvestable yield util-
ized by farmers to feed their livestock. In this experi-
ment, the fresh weight of crop residues harvested were
about 10.7 , 8.0, 7.2 ton ha"1 of corn stover, rice straw,

and peanut stalk, respectively. For comparison, the

average weight of weeds collected from the no-crop plots

was 4.6 ton ha-l'
The acacia biomass ranged from 94 to 157 g .m-1
row. There was no significant difference between acacia

biomass when its neighboring plants were corn, rice,
peanut, or weeds.

Root occupancy of a teak-crop combination was
different according to its distance from teak. Depth of
soil had no effect on root occupancy . Roots of the teak-
rice combination occupied the soil more extensively than
did the other teak-crop combinations.

Some changes in the chemical status of soil after

four months of plantation were observed. The surface soil

87

contained more nutrients ( N, P, organic C, Mg, K, Ca, and
Na ) than the subsurface soil. Nutrient concentrations in
the surface soil decreased after four months, while those
in the subsurface soil increased.

Patch weeded teak grown without a crop did not
perform better than when grown with a crop association. In
fact, it performed much more poorly. The order of positive
influence of companion crop with respect to teak growth
was rice > peanut > corn, at the first cropping season
( four months of plantation ) and peanut > rice > corn
at the second cropping season ( 16 months of plantation ).
Since the difference in the effect of rice or peanut on
teak was not significant, either one may be selected as
the best companion crop for teak. However, other consider-
ations such- as 1) the farmers’ cropping practice, and
2) possible allelopathic effects, had lead to selecting
rice over peanut.

Based on these observations on the first 16 months
of the plantation, it may be concluded that growing crops
in association with teak is ecologically justifiable and
the reasonable cropping sequence for tumpangsari practice
in the Wanagama I, or other areas with similar conditions

is, rice - peanut - corn.

BIBLIOGRAPHY

BIBLIOGRAPHY

Anonymous, 1982 Editorial. Journal of Agroforestry
Systems Vol. 1

--------------- , 1954 Weeding and planting methods for
Iggtogg grandis. Rep. For. Dept. Sudan, in For.
Abstr. 16, 1955 ( 425 ).

Atmosoedaryo, Soekiman and S.G. Banyard, 1979. The
prosperity approach to forest community development
in Java. Comm. For Rev. 57 ( 2 ): 89 - 96

----------- , and K. Wijayakusumah, 1979. Ecological
aspects of agroforestry in the low land and humid
tropics : Southeast Asia. In Chandler, T and David

Spurgeon (ed.) Proceeding of an International
Conference in Agroforestry. ICRAF, Nairobi, Kenya pp
117-128

Becking, J.H., 1928. Cultivation of teak in Java: study
about the results of different regeneration methods
of teak. Mededelingen Proefstation v.h. Boschwesen 22.

Beekman, H.A.J.M., 1949. Houteelt in Indonesie ( Silvi-
culture in Indonesia ). Veenman & Zonnen, Wageningen,
The Netherland. pp 386

Birowo, A.T., 1975 Employment and income aspects of the
cropping system in Indonesia. The Philippine Economic
Journal No. 27 Vol. XIV no 1 & 2 : 272-278

Boer, J.A. de , 1929 Eenige opmerken naar aaleiding van
ononderbroken bedekking van der bodem ( Some remarks
with reference to constant cover of the soil.

Tectona : 321-322

Boerboom, J.H.A., 1981. Some silvicultural aspects of
agroforestry. In Wiersum, K.F. ( ed. ): Viewpoints on
Agroforestry. Agricultural University Wageningen, The
Netherlands. p. 129 - 136.

Budowski, G. 1983. An attempt to quantify some current
agroforestry practices in Costa Rica. In Huxley, P.A.
( ed. ) Plant Research and Agroforestry. ICRAF,
Nairobi, Kenya. p 43-62.

88

 

89

Contant, R.B., 1979. Training and Education in Agroforestry
In Chandler, T and David Spurgeon (ed.) Proceeding of
an International Conference in Agroforestry. ICRAF,
Nairobi, Kenya p. 220 - 229

Coster, C.H. and Hardjowasono, M.S., 1935. Veldgewassen
in djati cultuuren. Een orienteeren onderzoek naar
den invloed van vreschillende veldgewassen op de ont-
wikelling vam den djati ( Tectona grandig ). The
influence of agricultural crops in taungya plantation
on the growth of teak. Tectona 28, 1935: 464-483

Darmokusumo, Darmakum, 1985. Regional Deve10pment of
Karst Areas with special reference to Gunung Kidul
District and its Problems. Ministry of Forestry,
1985. Unpublished paper 29 p.

De Veer, Van Alphen, 1957. The silviculture of gregari-
ous types--Teak cultivation in Java. FAO Forestry and
Forest Product Studies no.18. Tropical silviculture
vol.2, 1957 ( 216-232 ). FAO, Rome.

F.A.O. 1978. Forestry for local community development.
F.A.O. Forestry paper no.7, F.A.O. Rome, 1978

Grist, D.H. 1986 , Rice ( sixth edition ). Longman 645 p

Hamid, A., G.M. Paulsen, and H.G. Zandstra, 1982 Perform-
ance of Rice Grown after Upland Crops and Fallow in
the Humid Tropics. Paper 82-594-J, Dep. of Agronomy,
Kansas State Univ., Manhattan, KS 66506; and The IRRI
PO box 933, Manila, Philippine. 13 p.

Hardjosoediro, Soedarwono, Ir. 1972. Penelitian kemampuan
mandor tanam di Cepu ( Study on the working capacity
of plantation foreman at Cepu ). Yayasan Pembina
Fakultas Kehutanan UGM, Yogyakarta, Indonesia. 34 p.

Hart, H.M.J. ; Nolte, A.C., 1927 Verjonging en verpleging
van den djati (Regeneration and tending of the teak).
Tectona 20 : 199-217

Hauck, F.W., 1967. Experimental work to establish fertili-
zer recommendations in west africa. F.A.O. Soil
Bulletin no. 24

Hesterman, 0.8., M.P. Ruselle, C.C. Sheaffer, and G.H.
Heichel 1987. Nitrogen Utilization from Fertilizer
and Legume Residues in Legume- Corn Rotations.
Agron. J:79 :726-731

 

90

Hollerwoger, F., 1954. Is there a correlation in the teak
forest between crown diameter and the height of the
trees with regard to the diameter at breast height?.
Journal of Scientific Research in Indonesia, Djakarta
3 ( l ), 1954 : 3 - 20

Jones, M.J.,1975 Leaching of nitrate under maize at Samaru,
Nigeria. Tropical Agriculture, Trinidad. 52: 1-10

Kartasubrata, Yunus, 1978. Tumpangsari method for establish-
ment of teak plantation in Java. In Proceeding of a
Symposium on Tropical Agricultural Technologies,
Tsukuba, Japan. Tropical Agricultural Series 12:
141-152

Khan, Halim, M., 1963 Gunung Kidul ( An introduction to a
problem area in Java ). Ind. Journal of Geography
vol.3 no 4-6.

King, K.F.S., 1979. Concept of Agroforestry. In Chandler,
T. and David Spurgeon (ed.) Proceeding of an Inter-
national Conference in Agroforestry. ICRAF, Nairobi,
Kenya. p 1 - 14

King, K.F.S, and M.T. Chandler, 1978. The wasted land. The
Program of Work of the International Council for
Research in Agroforestry, ICRAF, Nairobi, Kenya.

Lugt, C.S., 1909. Nogmaals opslagkultuur en de z.g. kon-
tract ( Once again stump-sprout regeneration and the
so called contract ( tumpangsari ) plantation.
Tectona 2 : 441- 453

Manivel,L., and R.J. Weaver, 1974. Biometric correlations
between leaf area and length measurements of
"grenache" rape leaves. Hortsci. 9:27-28

Martodiwirjo, Soedjadi, 1981. The MAMA project. Perhutani
publ. no. KT 18.80, Jakarta, Indonesia. 34 p.

Mongi, H.O., 1979. Agroforestry extension : Needs and
Strategy . In Chandler, T. and David Spurgeon (ed.)
Proceeding of an International Conference in Agro-
forestry. ICRAF, Nairobi, Kenya. p. 229 - 256

Norman, M.J.T., C.J. Pearson and P.G.E. Searle, 1982. The
Ecology of tropical food crops. Cambridge University
Press P 82-102.

Nwoboshi, L.C. 1981 Soil productivity aspects of agri-
silviculture in the west African rain forest zone.
Agroecosystem 7 :263-270

91

------------- ,1984. Growth and Nutrient Requirements in
a Teak Plantation Age Series in Nigeria. II. Nutri-
ent Accumulation and Minimum Annual Requirements.
For. Sci. 30 : 35-40

Nye, P.H. and D.J. Greenland 1960. The soil under shift-
ing cultivation. Technical Commmunication no. 51
Common wealth Bureau of Soils Harpenden
( reprint 1965 ). 154 p.

Ojeniyi, 8.0. and 0.0. Agbede. 1980. Effects of single -
crop agrisilviculture on soil analysis. Expl. Agri.
16: 371-375

-------------- , 0.0. Agbede and J.A. Fagbenro. 1980.
Increasing food production in Nigeria: I Effects of
Agrisilviculture on soil chemical properties.

Soil Science 130: 76-81

Perhutani, 1974. Pedoman Penyelenggaraan Pembuatan Tanaman
Jati ( A teak plantation establishment manual ).
PHT 7 Seri produksi 6, Perhutani, Jakarta.

--------- , 1981. Buku Saku Statistik ( Statistical Pocket
Book ) 1976- 1980 . Perhutani, Jakarta. 24 p.

Rachadi, 1978. Inmas Tumpangsari di K.P.H. Bojonegoro
( Intensified tumpangsari at Bojonegoro forest dis-
trict). Perhutani Bojonegoro. 32 p.

Schmidt, F.H. and Ferguson, J.H.A., 1951. Rainfall types
based on wet and dry period ratios for Indonesia.
Verhandel. Djawatan Meteorologi dan Geofisika,
Djakarta 42 : 77 p.

Soekotjo, 1975. Laporan sementara Inmas tumpangsari di
Ngawi ( Preliminary report on intensified tumpangsari
in Ngawi). unpublished. Fakultas Kehutanan UGM, Yogya-
karta. 42 p.

Sukanto, M. 1969. Climate of Indonesia. in Arakawa, H.
(ed.), Climates of Northern and Eastern Asia. Worlds
Climate vol 8 : 215-229

Thorenaar, A., 1929 Ononderbroken bedekking van de bodem
( Constant cover of the soil ). Tectona , 1929 22:
318-320

Versluys, W. 1922 Acacia villosa Willd. sebagai pengganti
Leucaena glauca Benth ( Indonesian translation by
Pardiyan ). Tectona XV p 235-240

92

Wargo, Phillip, M., 1978. Correlation of leaf area with
length and width measurements of leaves of black oak,
white oak, and sugar maple. Research note NE-256,
Northern Forest Experiment Station. Forest Service,
USDA

Wehlburg, A.F., 1908. Nogeens opslagkultuur en de z.g.
kontract cultuur ( Once again stump -sprout regenerat-
ion and the so called contract (tumpangsari ). Tectona
1: 562-575.

Wetselaar, R. 1962. Nitrate distribution in tropical soils.
III. Downward movement and accumulation of nitrate in
the subsoil. Plant and Soil 16: 19-31.

Wiersum,K.F., 1981. Outline of the Agroforestry concept.
In Wiersum, K.F. ( ed. ): Viewpoints on Agroforestry.
Agricultural University Wageningen, The Netherlands
p.1-21

Wilde, S.A. 1958 Forest Soils. Ronald Press Company, New
York . 537 p.

Young, Anthony, 1976. Tropical Soils and Soil Survey.
Cambridge University Press, London. 468 p.

Zandstra, H.G., E.C. Price, J.A. Litsinger, and R. Morris,
1981. A methodology for On-farm Cropping System
Research IRRI, Philippines.

APPENDICES

APPENDIX A

F values and associated probabilities of. variables
influencing N concentration of surface ( O-lspcm ) and
subsurface 1 0-15 cm ) soils at three different distan-
ces from teak before the trial and four months after
planting

Source Degrees of F
Freedom Value Prob

Time 1 0.84 - ns
Distance 2 0.11 - ns
Time x Dist 2 1.26 0.33 ns
Depth 1 170.28 0.00 **
Time x Depth 1 36.28 0.00 **
Dist x Depth 2 1.00 - ns
Time x Dist x Depth 2 0.02 - ns
Crops 3 2.82 0.04 *
Time x Crops 3 3.44 0.02 *
Dist x Crops 6 0.35 - ns
Time x Dist x Crops 6 0.80 - ns
Depth x Crops 3 1.40 0.25 ns
Time x Depth x Crops 3 0.69 - ns
Dist x Depth x Crops 6 0.77 - ns
Time x Dist x Depth x

Crops 6 0.45 - ns

93

APPENDIX B

F values and associated probabilities of variables

influencing P concentration of surface 1 0-15 cm ) and

subsurface ( 0-15 cm ) soils at three different distan-
ces from teak before the trial and four months after

planting

Source Degrees of F
Freedom Value Prob

Time 1 2 02 0 29 ns
Distance 2 0.23 - ns
Time x Dist 2 1.07 0.39 ns
Depth 1 63.72 0.00 **
Time x Depth 1 17.57 0.01 **
Dist x Depth 2 0.63 - ns
Time x Dist x Depth 2 0.00 - ns
Crops 3 5.63 0.01 *
Time x Crops 3 0.91 -
Dist x Crops 6 0.96 - ns
Time x Dist x Crops 6 1.47 0.20 ns
Depth x Crops 3 0.82 - ns
Time x Depth x Crops 3 0.83 - ns
Dist x Depth x Crops 6 1.29 - ns
Time x Dist x Depth x

Crops 6 0.82 - ns

94