Spatial Analysis on Agricultural Land Suitability using Geographic Information System (GIS)

The agricultural sector is the main economic activity of the community and also a source of strengthening the people's economy and is the largest provider of employment. In addition, the agricultural sector is the preferred sector in most regions in Indonesia. This condition shows the need to pay attention to human development, especially in rural areas. In the long term, the agricultural sector is expected to increase to enable an increase in the economic welfare of the people, especially in rural areas.

Five criteria must be met to enable the agricultural sector to become the dominant sector in the regional economy. The five criteria are (1) contribution criteria: direct contribution to the achievement of national objectives, (2) articulating criteria: is the ability to encourage the growth of other economic sectors through synergistic relations between industries; (3) promotive criteria: the ability to create an environment conducive to growth and development of other economic sectors; (4) progressive criteria: the ability to grow sustainably at a fairly high rate, and (5) the criteria for resilience: the capacity to survive in the face of any shocks caused by economic, social or political turmoil. By fulfilling these five criteria, the agricultural sector will have both comparative and competitive advantage in the global economy (Simatupang et al., 2001).

To fulfill the five criteria above, it is also necessary to have several supporting factors for achieving one of them, namely land suitability. Where land suitability is the assessment and classification of land parcels in terms of their suitability for specified uses. Land suitability is assessed by comparing the quality of land and land use requirements.

The land suitability classification system can be divided into four categories: land suitability at the order level, land suitability at the class level, land suitability at the subclass level, and land suitability at the unit level. In that case also, FAO said that actual land suitability could be planted by three types of agricultural crop commodities, namely rice, corn and peanuts.

Rice is a crop that produces staple food for the people of Indonesia. The need for rice as a staple food will continue to increase from year to year in line with population growth. Corn is a food crop that can be used as a substitute for rice. Corn can be planted easily in Indonesia because it does not require special land and environmental conditions. Whereas Peanuts are used as raw material in the food industry and that the need for peanuts will increase from year to year.

In addition to land suitability, there are other factors that can support the success of production and productivity of the agricultural sector, namely the selection of crop commodities that are in accordance with the environment (land, height, etc.) that exist, where it will also indirectly affect the level of high or low income of farmers . government policies that need to be improved to support the improvement of farmers' welfare, especially in the supply of agricultural inputs such as fertilizers, pesticides, seeds, irrigation systems, and other agricultural inputs. As well as the distribution system (marketing) and the determination of the market price after harvesting also need to be considered so as not to disadvantage the farmers.

 Geographic Information Systems are computer-based systems that make it possible to handle geographically referenced data including data entry, management, manipulation and analysis, and data output. There are two types of digital data models in GIS: raster and vector formats. Geographic Information Systems are widely used in various fields of science, one of which is to map land suitability, especially for agriculture. With the help of the Geographic Information System data analysis process that can be done in a faster and better way with relatively greater data storage capacity compared to manual data.

Analysis to determine development priorities in the agricultural sector is based on physical factors where information is obtained through geographic information system techniques using climate, temperature and rainfall data and soil data. Slope maps and terrain maps and landform maps are used to produce land unit maps. The next step is the analysis of soil samples obtained in the field which are then analyzed in the laboratory to determine the physical properties of the soil at the research location. The data is then matched with the land unit map and the RBI map administration map so which locations are (very, moderate, marginal) suitable or not suitable for agricultural activities, especially for food crops (rice, peanuts, and corn)