الگوی بهینه‌ی کشت مبتنی بر معیارهای چندگانه‌ی اقتصادی، منطقه‌ای و پایداری کشاورزی در شهرستان ساری؛ کاربرد الگوی تلفیقی AHP و برنامه‌ریزی خطی

Introduction: Determining a suitable cropping pattern is an important task for planners and requires an exact and realistic decision-making process based on several goals and criteria corresponding to secure the interest of agricultural beneficiaries in long-term. Accordingly, this study reviews the current pattern operated by farmers in Sari, Iran, and intends to provide a cropping pattern that considers the multifold regional and agricultural sustainability criteria along with economic considerations.
Materials and Methods: In order to achieve the study goals, a consolidated model of AHP and Linear Programming was applied. For this purpose, we constructed a three-level AHP, including a goal (determining the weight of each crop), seven criteria, and seven alternatives. Profitability, compatibility with regional and geographical conditions, water consumption, environmental effects of cropping, job creation opportunities, skill and proficiency required for producing a crop, and risk taken to cultivate a crop were considered as the criteria in the model. Seven alternative crops including rice, wheat, rapeseed, barley, soybean, clover, and vegetables were considered too. The next step is determining the weight of each criterion with regard to the goal and the weight of each alternative with regard to each criteria. By multiplying these weights, final weights for various crops were obtained from the model. Derived weights for each crop were then applied as objective function coefficients in the Linear Programming model and the model was solved subject to the constraints.
Results and Discussion: Optimal cropping pattern determined based on the consolidated model of AHP and Linear Programming and the results compared to a scenario that only looks forward to maximizing the economic interests. Due to the low profitability of rapeseed and barley, these crops eliminated from the pattern in the profit-maximizing scenario. According to the results, the scenario provides 11.36% more profit than the current cropping pattern. In the consolidated model, we first calculated final weight for any crop. With a relative weight of 0.23, rice had the highest priority. Wheat, vegetables, clover, barely, rapeseed, and soybean weighed 0.17, 0.16, 0.14, 0.11, 0.1, 0.09 and took the respective priorities. In the next step, we use the weights for each crop as objective function coefficients in the Linear Programming model and solve the model subject to the constraints. Rice cultivation had the largest crop area with 15126 ha (62.52% of the entire crop area). Clover, vegetables, wheat, rapeseed, barely, and soybean stood behind the rice. Comparing the ideal cropping pattern, which was based on multifold criteria, with the current pattern showed that the most significant changes between the patterns occurred for wheat, soybean, and rapeseed crops so the recommended crop area for wheat in the optimal pattern increased by around 165% , however, the recommended crop area for soybean and rapeseed decreased by 96% and 75% respectively. The total profit of the ideal cropping pattern was 1,152,469,874,210 Rials. This shows that the optimal pattern caused an increase in profit by 3.63% compared to the current cropping pattern. Comparison between the results of consolidated model and profit-maximizing scenario shows that the optimal cropping pattern recommended by the consolidated model offers lower profits (lower than 8%) than the pattern offered by profit-maximizing model, however, the optimal pattern allows us to take other important criteria into account, including crop compatibility with regional and geographical conditions, water consumption, environmental effects of cropping, job creation opportunities, skill and proficiency required for producing a crop, and risk taken to cultivate a crop.
Conclusion: Using a consolidated model of AHP and Linear Programming, this study aimed to decide an optimal cropping pattern that considers the multifold regional and agricultural sustainability criteria beside economic considerations in Sari. The results of ideal cropping pattern in consolidated model recommended some changes distribute cropping area between crops and increased the profit compared to the current pattern. Comparison between the results of consolidated model and a scenario that only looks forward to maximizing the economic benefits shows that the ideal cropping pattern recommended by the consolidated model offers lower profits (lower than 8%) than the pattern offered by profit-maximizing scenario, however, the optimal pattern allows us to take other important criteria into account, including crop compatibility with regional and geographical conditions, water consumption, environmental effects of cropping, job creation opportunities, skill and proficiency required for producing a crop, and risk taken to cultivate a crop, which are so vital in current agricultural situation and result in significant long-term effects. Therefore, it is recommended to have the optimal cropping pattern operated in the region or at least, in parts of the district as a pilot project.