Ilmu Pertanian (Agricultural Science)

Soetarso, Soetarso

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Correlation of Harvest Index with Agronomic Characters and Their Heritability In Soybean (Glycine max (L.) Merr

Darwanto, Dwidjono H.

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Nasrullah, Nasrullah

Modelling of Nitrogen x Plant Population Interaction on Corn (Zea Mays L.)

Basunanda, Panjisakti

Siswandono, Siswandono

Genetic Parameter Estimation of Rambutan Seedling Morphologicaltraits For A Better Rootstock Performance

Masyhuri., Masyhuri

Comparative Advantage in Rice Production in Java

Malingereau, Jean Paul

223
,i COMMENTS ON "PEMAIRAN DAN PEMETAAN TANAH
SERTA PENGHARKATAN LAHAN DAERAH
TRANSMIGRASI" BY TETOYUWONO
NOTOHADIPRAWIRO
Jean Paul Malingreou *)
Tejoyuwono's short note in the October 1980 issue of IImu Pertanian (Tejoyuwono
Notohadiprawiro, Ilmu Pertanian II (8), pp. 427 - 435,1980. Yogyakarta) casts an en-
couragini note in the field of soil surveys. Indeed, a genuine recognition that soil studies
should serve at the same time scientific and practical purposes can only enhance the
effectiveness of the surveys and improve their usefulness in the overall context of agri-
cultural planning. History shows that too much dogmatism in soil surveying approaches
has frequently led to the isolation of pedologists outside the planning community and to
the regrettable underutilization of the results of their investigations.
In addition to his usual contribution to the earth sciences vocabulary in Bahasa Indo-
nesia (although we are not sure that all the proposed terms will be accepted by every-
one), Tejgyuwono has clearly stated the dual function of soil surveys. He recognizes
the reduced value of a soil map which cannot be translated in terms readily understan-
dable by the land use planning community. He stresses in this respect that a soil poten-
tial map is a more appropriate document than a soil map relying on a sophisticated
classification. The necessity of integrating soil investigations into a broader perspective
on land resources management is also recognized in the article.
What does not clearly emerge, however, is the procedure whereby data on various
dimensions of 'land', including soils, climate, landform, water regime, vegetation,
present land use ... can be combined to enable the analyst to make a realistic assessment
of the potential of an area to sustain agricultural production. Thus while we fully agree
with Tejoruwono's views, we would like to add the following comments dealing with
procedures for a better integration of the soil surveys with other aspects of land deve-
lopment. The topic of integrated approach to resources inventory and management
is very actual in Indonesia and points of methodology are important to consider because
they often condition the success of the tentatives made in that direction.
It is useful in this respect to redefine the concepts of soil (tanah)and land (lahan).
Land is disti& from andlncludes soil. Land encompasses'the physical environment,
including climate, Iandform, soils, hydrology, and vegetation to the extent that these
influence the present or potential use of the land (after Brinkman and Smyth, 1973).
The concept of land thus includes the past and present human activities on a given site.
Because ttre practical suitability of a given soil for a given use cannot be assessed without
taking into consideration all the other aspects of the environment, land rather than soil
alone is to be characterized.
t) 
Proj"ct Specialist. Agricultural Development Council, Yogyakarta'
Ilmu Pert. (Agric. Sci.) 3(5) 1982.
t
.L
t
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224
How does one acquire, without too much difficulty, such a complete and, if possible,
integrated view of an area ? The level of complexity of the adopted procedure will of
"orir" 
depends upon time, budget and expertise constraints. A Major problem'Tttlly
arises at the beginning of the exercise; it is related to the identification of a spatial unit
of land to be used as the base for the evaluation.
The objective is here to identify units of the landscape which for all practical pur-
por", pr"."rrt some degree of homogeneity in their resource endowment. It is only once
u, ug*"-"nt has been-rqached by all the concerned disciplines regarding the identifi-
catioln of such units that spatial planning can proceed in an integrated fashion. TVo ques-
tion immediately come to mind in this respect. At first, do such "land units" actually
exist in nature and second, how does one go about identifying them ?
Any unit of any classification is a mental construct based on defined criteria. For
example, physiognomic, floristic or functional criteria can be retained to classify vegeta-
tion. Accurate measurements of some soil characteristics are used to identify soil units
while a visual assessment of landforms is adopted to identify broad physiographic units.
There are therefore some systems of resource clasification which confine the surveyor
within narrow guidelines while others give him/her the latitude to "shape" a unit of
observation according to the objectives of the study'
The Foreword of the study carried out by the Soil Research Iastitute and the FAO in
the Cimanuk River Basin (SRi, 1976) provides an adequate description of the land unit
approach:
,,The Land. Unit is defined in terms of landforms, soils and present land cover/land
use. The basic element is the landform and the nattre/age of its formation' In some
cases the landform is typified by a dominant physiographic feature or a combination
of these; in other "u""tlt 
is only characterized by a single feature which can often
be of lower physiographic significance. This variability is inherent to the character
of landform and also to the nature of the study : areas with gleater development
possibilities demand a higher intensity in investigation than areas of less importan-
ce for rural develoPment".
,,Additional features of the Land Units observed and recorded during more detailed
field investigations are implied as follows :
1. The soils data may indicate that a further subdivision of the units is necessary
to render them homogeneous at the soil association level. Wherever possible
the Detailed Reconnaissance Soil Map of the Cimanuk Watershed Area (Soil
Research Institute, Bogor, 1976) has been used for a further delineation of the
Land Units.
2. Dataon other features of the Land units, for example present land cover/land
use, are considered as supplementary information to the already defined units ' "
These two quotations show that landforms are given a special attention in this
approach. while one has to recognize that the landforms do not tell everything about
an area, it is important to note the various advantages of a land form of physiographic
approach to resource inventories. At first, landforms can easily be recognized on air-
p't otograprrs and other remote sensing products. This can speed the surveys to an appre-
"iuUtu "*i"rt. 
Second, there is usually a high level of coincidence between the lanfdforms
and the distributions of other resources such as soils, surface and underground water,
drainage characteristics, macro and microclimate and, to some extent the land use'
Last but not least, landform terms are easily understood by the non-specialists because
\tl
225
,i-
of their evocative nature. The importance of this last point was also recognized by Tejo-
yuwono (op.cit.) who insists on the readability (keterbacaanl of the soil maps.
Obviously, in areas of reduced topographical constrasts or in the case of high in-
tensity surveys (such as the ones required in problem soils areas), those principles are
not always applicable. Pragmatism then dictates the selection of an hierarchy of mapping
criteria; the quality of the results will then depend upon the experience of the surveyor.
The result of a land resource survey carried out using the land unit approach is a
map showing the spatial distribution of those units and a table describing each of them
in terms of soils (often soil associations), water availability, vegetation, climate, present
land use or any other pertinent characteristics. The subsequent evaluation of each unit
is carried out in a systematic fashion with the assumption that each land unit presents
a anique and uniform combination of resources.
Another approach which is also to be mentioned here is based on the execution of
purely thematic surveys (soils, vegetation, hydrology ... ) leading to the preparation
of a series of maps which are then recombined using the ouerlay technique. Anyone
who has attempted to recombine more than three or four thematic maps will testify
that such a procedure can quickly become rather cumbersome. The utilization of digital
techniques of spatial representation may alleviate some of those problems and allow
some flexibility in the combination of selested parameters on a unique data base (some
efforts are presently made in that direction by BAKOSURTANAL using the COMARC
mapping system).
A last point which was not clearly expressed in Tejoyuwono's article is that resource
evaluation in general should not be concerned with resources per se but with their use.
Resources such as soils or water cannot be evaluated in absolute terms but must be con-
sidered in respect to specific uses. It is thus important to define such uses. While in
some instances general classes of possible uses can be retained (such as, for example,
subsistence agriculture, transmigration settlements, estate crops, forest etc ... ), the
optimization of resources management requires that the detailed definition of possible
land utilization types be worked out (FAO, 1976). Indeed, the right choice and appro-
priate description of a range of possible alternative uses will condition the success of the
evaluation. For example , an area can be found not suitable for a given type of land use
and suitable for another. If, because of an oversight, this latter land use has not been
considered, the evaluati on will per force be incomplete .
The transmigration programme in Indonesia is case in point where the strict adhe-
rence to a unique land use model has for many years led to the rejection of areas which
could otherwise be considered for other types of use compatible with generai transmigra-
tion objectives. In the same line,cases have occured where the fixed land use type has
been 'forced ' into areas better suited for a modified version of that basic model.
In resources short situation, and this seems to be the case in many transmigration
areas, the land use should be desippred to fit the pattern of resources availability and dis-
tribution. Once again this requires some prapgnatism in the approach. The definition
of possible land utilization types for Indonesia has not yet received enough attention
from agriculturists and socio-economists; it is a challengrng task which calls for the appli-
cation of imaginative approaches. One has to keep in mind that the diversity of envi-
ronments is very large in the archipelago and that criteria of production have to be com-
bined with appropriate environmental protection measures" Such requirements singu-
larly complicate the task.
The preceding remarks have hopefully shown that while there is a general agree-
ment on the need to adapt resources surveys to the realities of the planning processes,
\
t'
l,
into a coherent and flexible
of methodologies must be given
References
Brinkman, R. and A.J. Srnyth (1973) Land evaluation for rural purposes' Intern' Inst'
Inst. Land Reclam, and Improuement' Publ' 17' Wageningen'
fAO (19?8) Land evaluation. Soi/s Bulletin 32'
Indonesia. Department of Agriculture. Soil Research Institute' & FAO (1976) Detail
relconnaissance; Land. resources suruey of the cimanuk watershed area. P:ubl' 7a'
Bogor.
Notohadiprawiro, Tejoyuwono ( 1980)
Pemairan dan pemetaan tanah serta pengharkatan lahan daerah transmigrasi'
Ilmu Pertanian (Agric. Sci. ) 2 18]' : 247 - 435'
I
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226
*


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