Abstract :
The land suitability of agricultural lands of the North Khorasan Province (Iran) for cumin production was assessed. For this purpose, Digital elevation model (DEM) was provided from 1/25000 digital maps and surface analysis functions were used to create topographic layers and multiple regression models were provided, tested and used to create rainfall, average temperature and extreme temperatures layers for cumin growing season. Three Scenarios were used to determine land suitability of study area for cumin production. (1): areas with minimum temperatures ? 3 °C in January, February and March, rainfall ? 160 mm, slope ? 15% and South and east aspects. (2): areas with minimum temperatures ? 3 °C in March, rainfall ? 160 mm, slope ? 15% and South and east aspects. (3): areas with minimum temperatures ? 3 °C in March slope ? 15% and South and east aspects. Scenario I was considered to provide probability map of cumin cultivation in the best climatic and topographic conditions. Scenario II was considered for March sowing date onward, and January and February sowing dates were avoided. In scenario III, we assumed that fungal diseases which are resulted from high soil moisture content after receiving more than 160 mm rainfall will control by different management options. Our results indicated that pre- March sowing dates are not advised, because the probability maps of extreme temperature occurrence showed these regions are high risk and vulnerable. Only 6.2 and 21.9 % of total agricultural lands were detected as favorable regions for cumin production base on Scenarios of II and III, respectively. Our results indicated that according to special needed considerations to sow cumin in the regions were detected by II and III scenarios, and reducing the cumin yield in late sowing dates, it seems this medicinal crop could not be advised to extend its cultivation in medicinal plants extending program in this province. Our results revealed that GIS_based plans can help us to create a shortcut for conscious decision making in large scales, which is a necessity for new crops, especially medicinal plants such as cumin.
