LAND RESOURCES INFORMATION SYSTEMS AS DECISION SUPPORT TOOL IN AGRICULTURAL DEVELOPMENT IN INDONESIA

Istiqlal Amien and E. Runtunuwu

Indonesian Agroclimate and Hydrology Research Institute

INTRODUCTION

Agriculture in Indonesia that withstands the prolonged economic crisis is unable to crater the still growing market demands. Domestically the agriculture is also threatened by better quality imported agricultural products. This is among other because of the very limited agricultural land that often inappropriately utilized. Except for few commodities, agriculture initially was the cater the basic need of the farmers. Therefore, many were intended to produce the daily need of the farmers such as food without much consideration on the advantages of the existing resources. In the area of globalization and with increasing awareness of environment safety the agriculture is urgently need to be oriented. The land resources should be utilized correctly with appropriate management to produce commodities that are able to compete in wider markets.

For that purpose, land resources information with the utilization alternatives is imperative. Land information such as soil, water and climate has been collected separately in the past. But it was very difficult for the users to digest the information that was not always systematically prepared. Therefore, with agroecological approach that combines information on physiography, climate, and soil land resource information system was initiated. This information can be fed into the expert system model to delineate areas for conservation and production forests, perennial crop plantations, agroforestry and annual crop farming. Further crop options for particular agricultural systems, as well as cropping patterns for annual crops can be generated. Combination between the product agroecological map and present land use delineates the under, proper, and over utilization areas.

AEZ DEVELOPMENT IN INDONESIA

The rapid change in world economy and increasing awareness in environmental oblige Indonesia to reorient and restructure its agriculture. The cope with change and to facilitate research dissemination as well as acquiring farmer feed back, Agency for Agricultural Research and Development (AARD), Ministry of Agriculture of Indonesia embarks in a regionalization program by establishing AIATs (Assesment Institute for Agriculture Technology). However, the condition and potential of natural resources within the areas are either poorly understood or not available. Therefore, methods in resource inventory and analysis for the regions need to improved, standardized, and disseminated through the AIATs personnels.

With the intensive training and guidance the agroecological zones delineation of most parts of Indonesia at exploration scale was completed. With this scale areas of an economic scale for agriculture development of 250 hectares can be mapped. This valuable information at limited was utilized in the each region for development planning.

The provincial agroecological zones maps will be very useful when regions with significant economic ties be combined in the form of atlas covering adjacent regions in a development entity. Therefore, integrated regional development can be planned properly to avoid competition and promoting regional cooperation. With this attempt national integration through promotion of international trade can be materialized.

Considering the inter-regional ties and the size of the regions, the atlases will be published in five volumes: (I) Sulawesi and Maluku, (II) Kalimantan, (III) Java and (IV) Nusa Tenggara, (V) Sumatra and (VI) Irian Jaya. Because of the limited time and funds and considering the acceleration of development in eastern Indonesia until now only the first volume, Sulawesi and Maluku is published. Hopefully in the near future funds are available to publish the other volumes.

There are four steps can be divided for AEZ development are: (1) Standardization of AEZ characterization and delineation method, (2) Training, application and supervision in the AEZ delineation and analysis, (3) Dissemination of AEZ analytical results to the end-users (stake-holders), and (4). Compilation and refinement of Agroecological Zone Atlas of Indonesia at 1: 250 000 scale (Table 1).

Table 1. History of AEZ development in AARD

AEZ MATERIALS AND METHODS

The AEZ materials and methods can be grouped into land resources database, expert system, Geographic Information System (GIS), and its link for agroecological analysis (Figure 1). The land resource database is obtained by combining various data layers (spatial and tabular data) on the physical aspects of agricultural environments such as climate, landform and soil. The expert system model uses the land resource database to determine land suitabilities or productivity, and to determine optimum land resources allocations. GIS has emerged as powerful tools in the management and analysis of the large amount of data, statistical, spatial and temporal for land use decisions. AEZ map and information are generated based on land resources database, expert system, and GIS.

LAND RESOURCES DATABASE

In the compilation of inventories of land resources, AEZ studies normally use large quantities of data. For direct viewing of information and for access by models for land suitability or productivity assessment, these data are most conveniently stored in databases. In this work, minimum data requirement for AEZ delineation is climate (moisture and temperature regimes), physiography, soils (texture, acidity, and drainage), and land use.

EXPERT SYSTEM

Once the essential data are stored in the databases, AEZ uses models to derive quantitative outputs describing crop suitability and agriculture system. Models represent a simplification of a more complex reality and the level of detail of the model should be consistent with the objectives of the study, the availability of data, and the knowledge base from which inferences can be drawn.

CSARD developed an expert system as a great tool to make the best of currently available knowledge based on field experience for evaluating the crop suitability and agriculture systems as presented in Figure 2. Although the conditions being used to arrive at conclusions are descriptive characteristics of soil taxonomy, the system is developed by production rules rather than by frames. This allows the system to use “heuristic” type of knowledge and can further proceed to the next step after the first conclusion.

This expert system tries to give recommendation on proper agricultural systems based on proper agricultural systems based on land characteristics such as slope, soil texture and acidity. Considering steep slope, coarse texture or deep peat and very low pH as limitations, on different agricultural system including annual crops, permanent crops and forestry.

On selection of specific crop that can be grown on particular land, the system requires input data on soil texture, soil acidity, moisture, and temperature regimes. Recommendations will be given on wide ranges of cereals, root crops, grain legumes, sugarcane, tobacco, fiber crops, vegetable, oil crops, and rubber based on the soil and climatic conditions. Crop suitability is generally limited by inadequate or excessive water and extreme temperature.

The system is further expanded to cover cropping system when given input data on water supply. Although it is not always accurate, water supply is inferred from drainage and the number of consecutive months with rainfall more than 100 mm. Recommendation on methods of P fertilization will be given based on soil clay mineralogy. Particular treatments of the soil such as organic fertilization and appropriate condition for soil tillage are also given based on soil mineralogy. The system will also give cautions on problem soil such as potential acid sulfate soil and alkaline pH.

Often the user does not have available data to feed the system. In this case, the system utilizes “heuristic” information from experience in the field. The system tries to infer most of the input data by asking simple questions on distinct soil characteristics. Soil acidity is inferred by native vegetation; moisture regime is inferred by soil drainage and consecutive dry months in which rainfall is less than 60 mm in one year. Poor or pounded drainage indicates that the soil has aquic moisture regime. Number of consecutive dry months will determine whether the moisture regime is udic, ustic or semi aridic.

            Because the system is limited to the Tropics, the temperature regime is inferred from the elevation of the land. Elevation less than 600 m above sea level is considered isohyperthermic, between 600 to 2000 m is isothermic and more than 2000 m is isomesic.

A more complicated inferred is involved when determining the soil clay mineralogy. This is based on several distinct soil characteristics such as soil parent material, soil texture, color of subsoil and whether or not the soil cracked in dry season. Volcanic ash material characterizes amorphous oxides and cracked soil is sign of smectitic minerals. The color of surface soil is generally darker than the subsoil because of its relatively high organic matter content. Therefore input data includes the color of subsoil. Oxidic minerals make the color of subsoil reddish or yellowish.

Because of much of its knowledge base is “heuristic type” in its expansion to soil and crop management, this expert system was developed in rule-based format with forward-chaining approach. The system has 5 variables, 15 qualifiers, and 99 choices organized in 139 rules. More rules will be added when the knowledge base has been expanded to include other crops and management aspect.

GEOGRAPHIC INFORMATION SYSTEM

The land resources data which consist of three main layers are slope and soil layer, moisture regime layer, and temperature regime layer have been overlaid by GIS tool to extract the agro ecological cell which assumed has a homogeny physics characteristics. This GIS tool facilities future utilization, updating, and improvement of the data inputs and application results of AEZ analysis.

AGROECLOGICAL ANALYSYS AND LAND DEGRADATION

FAO (1999) noted that land degradation can be understood as the set of processes that lower the current and/or potential capability of the land to produce (quantitatively or qualitatively) goods or services. By overlaying the AEZ map on present land use, there are three combinations can be involved as shown in Figure 2. Over utilization can became as one indicator of the land degradation processes which are phenomena that cause a decrease in the quality of land, particularly of soil. For the sake of relation between AEZ map and the land degradation, two concepts are useful in regards in further investigations are present rate and risk of land degradation.

APPLICATION: DELINEATION OF AEZ OF SULAWESI AND MALUKU

The above tools were illustrated on Sulawesi and Maluku at scale 1:250.000. In general, Sulawesi and Maluku are divided into seven zones as shown in Figure 3, with each further divided into twelve sub zones (Table 2). The alternative agricultural systems and crop options for each sub zones are presented in Table 2 also. Figure 4 presented an example of the sub zones in detail.

Table 2. AEZ of Sulawesi and Maluku

Table 2. Continued