بکارگیری مدل اگرواکولوژیکی فائو برای مکان‌یابی مناطق مستعد کشت پسته در استان آذربایجان شرقی

مدل اگرواکولوژیکی فائو تعیین توان بالقوه و تخصیص کاربری های متناسب با توان سرزمین است که می تواند بین توان طبیعی محیط، نیاز جوامع، کاربری ها و فعالیت های انسان رابطه ای منطقی و سازگاری پایداری بوجود آورد. این پژوهش به منظور مکانیابی مناطق مستعد کاشت پسته با روش تحلیل سلسله مراتبی (ahp) و با در نظر گرفتن نیازهای اگرواکولوژیکی این محصول در محیط سیستم اطلاعات جغرافیایی صورت گرفت. داده های مورد استفاده شامل اطلاعات مربوط به زمین، خاک و داده های اقلیمی با طول دوره آماری مشترک30 ساله از ایستگاه های سینوپتیک استخراج شدند. داده ها در قالب بانک اطلاعاتی جمع آوری و پس از پردازش به صورت لایه‌های رقومی در محیط سامانه آرک‌جی‌ای‌اس ذخیره شد. برای تحلیل فضایی، اطّلاعات به نرم‌افزار اکسپرت چویس وارد و خوشه بندی، ارزش گذاری معیارها و تلفیق اطّلاعات انجام و در نهایت لایه نهایی به صورت نقشه ارائه شد. بیشترین وزن زیر معیارها بترتیب به شیب زمین، میانگین دمای حداقل سردترین ماه سال و شوری خاک و کمترین وزن به میانگین دما در مرحله گرده‌افشانی تعلق گرفت. نتایج نشان داد 3887 کیلومتر مربع یا 8/5 درصد از سطح استان با محدودیت کم برای کشت این محصول در کلاس نسبتاً مناسب قرار دارند. این اراضی عمدتاً منطبق بر اراضی کشاورزی غرب استان است. 6250 کیلومتر مربع (13/6 درصد) از اراضی در کلاس تناسب بحرانی و 35663 کیلومتر مربع (77/9 درصد) اراضی در کلاس نامناسب قرار دارند به استثنای دشت میانه بقیه اراضی مستعد کاشت پسته در شرق استان و در حاشیه دریاچه ارومیه قرار دارند. الباقی مناطق استان برای کاشت این محصول در کلاس های تناسب بحرانی و نامناسب قرار دارند. محدودیت های شاخص این مناطق برای کشت پسته محدودیت های دمایی، رطوبت نسبی بالا در مرحله گرده افشانی، شوری خاک و شیبدار بودن اراضی است.

Application of FAO Agro-ecological Model for Locating Areas Prone to Pistachio Cultivation in East Azerbaijan Province

Introduction: FAO agroecological model determines the production capacity, creating a logical relationship between the natural potential of the environment, the needs of communities, human activities, and sustainable adaptation. With the development of plant growth simulation models, researchers have begun a largescale effort to agroecological zoning of various crops on a regional scale. In this method, an area was divided into homogeneous units with maximum similarity in terms of climate and land characteristics. Then, the potential yield map predicted by a simulation model is used for zoning. Pistachio is a subtropical plant that has long been cultivated in the central areas of Iran. With the occurrence of drought in the last two decades, farmers cultivated Pistachio in East Azerbaijan province without considering this crop requirement. This study aimed to use the AHP model to evaluate the suitability of East Azerbaijan lands for cultivating pistachio.Methods and Materials: East Azerbaijan province is located in the northwest of Iran, between the latitudes of 36˚ and 45’ to 39˚ and 26’ N and the longitudes of 45˚ and 5’ to 48˚ and 22’ E based on the geographic coordinate system. The area of the province is 45800 square kilometers. The climate is generally cold and semiarid, but it has different climates due to its diverse and extensive topography. The area of agricultural lands is estimated to be 18,000 square kilometers, which is about 39% of the total area. In this research, climatic data were collected for 30 years from Tabriz, Jolfa, Mianeh, Sarab, Maraghe, and Malekan synoptic stations, and from four neighboring stations of Orumieh, Khoy, Miandoab, and Parsabad. Three criteria (i.e. climate, land, and soil) and 11 subcriteria were studied. The subclimatic criteria included the average temperature of the growing season, average temperature in the pollination stage, absolute minimum temperature in the coldest month of the year, and average percentage of relative humidity in the flowering stage. Land criteria were land use subcriteria, land slope, and slope directions, and soil criteria were salinity (electrical conductivity of saturated extract), pH, soil texture, and soil lime content (CaCO3). The results of the analysis of about 9000 soil samples were prepared for zoning of soil factors from East Azerbaijan Agricultural and Natural Resources Research Center. Land characteristics of slope map and aspects were prepared from the digital elevation map of the study area and land use map was obtained base on the map provided by the Forests and Rangelands Research Institute of Iran. The parameters were then weighted upon AHP by the parameter importance for each region. Data were transferred to Expert Choice software and clustered, rated, integrated for producing the final layer.Results and Discussion: According to the AHP model, there are no entirely suitable class areas for pistachio cultivation in East Azerbaijan province. Because one or more factors or subcriteria created low restrictions for the cultivation of this crop. The results showed that 3887 square kilometers or 8.5% of the area was classified as a relatively suitable class. Although this area has low restrictions for pistachio planting, the profitability of this complex has increased the area of pistachio orchards rapidly. The suitable lands are mainly located by the agricultural lands and if water requirement could be met, they can be allocated for planting. The low water requirement and tolerance to salinity compared to other crops can be considered as the advantages of cultivating pistachio. Since 1998, droughts have occurred in different areas of the province. It caused a decrease in agricultural products by up to 35%. The declining water level of Lake Urmia is one of the consequences of the recent droughts, deteriorating the groundwater quantity and quality. The 6250 square kilometers (13.6%) of the province’s lands was classified as the critically suitable class. Some of the subcriteria studied in these lands such as the average temperature of pollination period, the average temperature of the growth period, amount and direction of slope, and soil texture were in the critical classes. The 35663 square kilometers (77.9%) of the studied lands were found to be unsuitable (N). The main reason for the unsuitability was the very high salinity of lands, as seen in the soil salinity map. Although it is a modifiable factor, the lack of quality for leaching, heavy soil texture, and the impossibility of draining drainage due to flatness, render the reclamation of these lands impossible. Under the current situation, East Azerbaijan province is much more capable of planting this crop. However, it is necessary to conduct more detailed studies to avoid pistachio cultivation in marginal suitable lands.