Mean, Maximum, and Minimum Monthly Rainfall during 1992-2011. 

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... suitability is the ability of a given type of land to support a defined use. It is assessed considering rational cropping system, for optimizing the use of a piece of land for a specific use (FAO 1976; Sys et al. 1991). The suitability is a function of crop requirements and land characteristics and it is a measure of how well the qualities of land unit match the requirements of a particular form of land use (FAO 1976). The process of land suitability analysis involved evaluation and grouping of specific areas of land in terms of their suitability for a defined use. The principles of sustainable development make land-use suitability analysis become increasingly complex due to consideration of different requirements/criteria. It includes consideration not only inherent capacity of a land unit to support a specific land use for a long period of time without deterioration, but also the socioeconomic and environmental costs. Geographic Information System (GIS) is considered as the powerful tool for input, storage and retrieval, manipulation and analysis, and output of spatial and attribute data. Meanwhile, land-use suitability analysis is required to handle both spatial and attribute data in many data layers. Therefore, it is appropriate to use GIS to exploit its strong capability in handling spatial data. There are several methods and approaches for land evaluation; namely simple limitation, limitation, and parametric methods. Simple limitation method compares and matches land characteristics with plant requirements. While limitation method refers to the magnitude of limiting factors belong of the evaluated land (FAO 1976). In this case, land suitability class is dictated by its availability (S) and non-availability (N). Parametric method values different land characteristics in maximum (usually 100) to the minimum scale (Sys et al . 1991). Each land character will be rated and calculated using mathematical formula to obtain land productivity based on climatic data. Plant production data input can predict land actual productivity (Juniarti 2003). Land evaluation is classified according to its availability level (FAO 1996) as following: Ordo: categorizing land suitability as suitable (S) and not suitable (N). Class: further classified the suitable land (S) as highly suitable (S ), moderately suitable (S ) and 1 2 marginally suitable (S ). The S land has no, or 3 1 insignificant limitations to the given type of use, S land have minor limitations to the given type of 2 use, and S land has moderate limitations to the 3 given type of use. The N ordo is classified as N 1 (currently not suitable) because it has severe limitations that preclude the given type of use, but can be improved by specific management, and N 2 (permanently not suitable) since it has so severe limitations that are very difficult to be overcome. Since 1965, maize production has increased from 1 MT/ ha to 1.69 MT/ha in 1986 and 6 MT/ha in 1989. Presently maize yield has reached 8 to 10 MT/ha. Low maize yield is mainly due to the soil condition that is not fully suitable for maize (Siradz 1992). Increasing maize yield in Inceptisols can be achieved by increasing soil fertility using combination of 300 kg urea/ha, 125 kg SP-36/ha, and 75 kg KCl/ha to provide N, P, and K nutrient (Botutihe 2000). In 2011, Gorontalo Province contributes 4% of Indonesian maize product and the effort to increase maize product is being promoted by means of agropolitan program. Nevertheless, spatial data concerning land suitability for maize has not been provided. Providing spatial data on land suitability for maize is necessary as to optimize maize yield as well as soil productivity and to prevent soil quality degradation through soil erosion. In this study, limitation method for land evaluation integrated with GIS was applied to evaluate the suitability of the agricultural land of the study area for maize using the relevant variables of soil physical and chemical parameters. Also, fertilizer recommendation as well as farmers perception on agropolitan program have been generated. The study was conducted at Limboto Basin, Gorontalo, Indonesia (0.30’49"-0.47’42" N and 122.41’52"- 123.53’49"E with total area of 91,199 Ha. During the last decade the study area has been suffered from flood and inundation (Figure 1). High rainfall occurs from November to March and low rainfall usually takes place from August to September (Figure 2). Mean monthly temperature usually indicated by tropical hot and humid temperature that range from 26 to 27 O C, while mean monthly humidity ranges from 73 to 83% (Figure 3). Land evaluation was conducted employing the Agro Ecological Zone (FAO 1976) and Soil and Agro climate Research Center (1980) procedures. The study area was deliniated as preserved, buffer, and cultivated zones based on the elevation, slope, erosion hazard, and forest status. Preserved forest, rice field, residential, and other publc facilities were excluded and eliminated (Figure 4). The remaining land was then evaluated based on slopes and landuse to classify land unit (Figure 5). Soil samples were collected from each land unit for chemical and physical laboratory analyses. Meanwhile, farmer perception regarding maize cultivation on their farmland were observed by means of questionnaire. Spatial analysis was carried out employing Arc View version 3.2 computer software. The observed biophysics and chemical as well as socio economic data is presented in Table 1. Table 2 shows that only about 36,000 ha of total 78,000 ha was studied. Landuse type of the study area (Figure 6), excluding forest, rice field, and public facilities, consisted of annual and mixed crops, bushes, coconut, and secondary forest. Table 2 also pinpoints that about 70% of the study area was situated on slightly steep land. In addition, about 14,000 ha of 36,000 ha study area has been planted with annual crop while 11,000 ha planted with coconut. Land suitability for maize is presented in Table 3. It was found that about 21,000 ha of the study area categorized as moderately suitable for maize while about 13,000 ha classified as marginally suitable. Among those suitable area, the limiting factors were temperature, rainfall, drainage, and nutrient availability. Findings on farmer perception regarding maize cultivation on their farmland revealed that 69% farmers in favor of maize cultivation, 26% were not sure and only 6% did not want to cultivate maize on their ...