Evaluation of Land Suitability for Horticultural UseCase Study: Saman County, Chaharmahal and Bakhtiari Province

Agriculture is the main source of national income and food for all developing countries, but the main problem facing many managers and farmers is when and where they can cultivate. Horticulture is one of the agricultural activities, the maintenance and development of which requires sustainable economic, social, cultural, ecological and institutional infrastructure. It also requires the participation and comprehensive planning at a local to national scale. The first step in achieving sustainable development, especially in the agricultural activities and the subsequent orchard farming, is to recognize the ecological potential and the land capability in each region. In this regard, the knowledge of land evaluation plays a decisive role in determining the land suitability or evaluating the ecological potential of each region for the intended uses, including the development of gardens. Numerous studies have been conducted to evaluate the land suitability for crop cultivation, including horticultural and agricultural products. Since orchards require more investment and time than crop farming, the importance of basic studies and research for the orchards will be much greater than that the crop; because if an unsuitable land is used for orchard establishment, after it, for several years, more important than wasting the money paid is the loss of time, which is not compensable. But, only one crop season is lost for crop farming.

In Chaharmahal and Bakhtiari province, the development of the orchard is very important for the people as well as the relevant officials. Therefore, the selection of the suitable location for the orchard farming is a very important issue. For this purpose, this research was conducted with the aim of achieving the best and most sustainable use of land in Saman County, which has the first rank in the province with about 13,000 hectares of gardens. Due to the climate of this area, the orchard products for cold regions, such as apricots, almonds, apples, peaches and grapes was selected and the possibility of sustainable development of these orchards was studied using the land suitability evaluation based on the FAO standard method. For this purpose, the land characteristics (LC) related to the intended crops, which mostly included the climatic characteristics and the characteristics of the soil and the land, were first collected and classified. Then, the requirements of the these crops or products were determined and at the end, the characteristics or qualities collected were compared and evaluated with the requirement tables of the selected crops. Each land feature was then given a class or numerical value, which combined two important indicators, including the climate index and the land index. In this study, the process of land suitability assessment was performed with a size approach and numerical (parametric) method and then land fit maps of the desired products were prepared.

Table 1 shows the class and subclass of land suitability for apricots. As can be seen, 42530.7 hectares or 86.87% of the whole land are in the suitable order. The subclasses include climatic (c) and soil physical (s) limitations. The most important soil physical limiting factors are soil depth, lime percentage and gravel percentage. Also, the land with an area of ​​6429.7 hectares or 13.13% of the land is in the not-suitable order, which due to the limitations of the gravel percentage and soil depth is in the permanently unsuitable class or N2s class.The results of land suitability assessment for peaches, apples, grapes, and almonds are shown in tables 2 and 3. The findings showed that according to climatic and soil characteristics, different regions had different degrees of proportionality or ecological potential, so that the study area had S3 and N classes in 86.87% and 13.33% of the area, respectively.For grapes and almonds, the land suitability classes were S2, S3 and N classes, in 21.90%, 65.57% and 90% of the area, respectively (Table 3). The most important limitations were the soil depth, gravel, slope, and climatic constraints. According to such findings, planners and decision makers can plan and choose the best options to take into account both the product profitability and sustainability. Of course, in addition to ecological requirements, it is recommended to study other requirements such as social characteristics, economic conditions, cultural acceptance, and the current situation of orchards to complete the process of sustainable development for horticulture.
Table 1. Land Suitability Classification for Apricots