Land suitability determination and estimation of wheat production potential in Shadegan area

Planning for optimum use of land causes the maximum profoitable. It also utilizes the land with respect to its potentiality in an appropriate way. Any utilization of land over its capability will cause degradation and yield reduction in long-term duration. In this respect the necessity of Land suitability determination for optimum use taking into account environmental, socioeconomic factors to sustainable development is an important step in the process of land use planning. The study area covers 34000 hectares, located in Shadegan, Khouzestan province. It is between 30º 34΄ to 30º 48΄ north latitude and 48º 37ó to 48º 47΄ east longitudes. Climatic data was derived based on nearest synoptic station (Bandar Mahshahr) to the study area. General information such as main crops, alternation condition, yield as well as socioeconomic information through farmers and existing services center was collected. The studied sites were selected based on semi-detailed soil survey report of Shadegan. In this respect representative profiles of 51 Land Map Units were studied and soil samples were taken for physical and chemical analysis. After data collection such as climatic requirements, landscape and soil requirements for selected crop, land suitability evaluation was determined based on ALES. Finally a database including Land Characteristics, Land Quality and crop requirements was created in ALES. Climatic data and Land characteristics of the study area were matched with climatic and crop requirements respectively using ALES and the land suitability class was attributed according to the less favorable characteristics. The results showed that most areas fall under moderately suitable class (S2) for irrigated wheat although due to soil limitations they vary from S2 to N based on ALES software. In a later step, production potential was calculated and obtained as 6980 kg per hectare for the study area based on (Sys, 1991). Finally land production potential was determined for each land map units taking into account of mentioned Irrigation Potential Yield and soil limitations, and varied from 293.2 to 4090.3 kg per hectare. It was also revealed main soil-related limitations caused to decrease land suitability and yield, are salinity, alkalinity and calcium carbonate. The result of quantity suitability also showed that most areas fall under moderately suitable class (S2) for irrigated wheat. It is to be noted that production potential and land suitability maps of wheat were drawn using ILWIS (GIS) software.