Introduction: Iran is considered one of the high-risk regions in terms of food security, which also requires imports to secure its food, including grains. In this regard, the country's top documents have also considered food security as one of the priorities. Food insecurity can lead to social and political instability in different systems. Therefore, ensuring food security in any country is one of the basic conditions for ensuring national security. In this regard, agricultural production plays a significant role in food security, but increasing agricultural production sometimes requires the use of more inputs. Given the limited resources for agricultural production, optimizing the use of those resources should be considered in order to achieve important goals. On the other hand, excessive cultivation of crops such as rice, despite generating high income for farmers, may lead to neglecting the sufficient production of crops such as wheat, barley, and oilseeds, which play a significant role in food security. For this reason, it is necessary to design a model to provide an appropriate cultivation pattern containing products from all groups. In addition to the importance of the quality of the products produced in terms of calories and nutrients, the production of some products, such as oilseeds, is also essential. According to the above, planners usually face multiple goals in determining the optimal cropping pattern. In this study, goal programming model has been used to optimize the cultivation of major crops in the Rudpey District of Sari County, but its main difference from other studies is the goal of improving food security by considering calories and nutrients in products such as protein, iron, calcium, potassium, and magnesium. This study also paid attention to the development of oilseed cultivation in order to create a safety margin in oil production.
Materials and Methods: In this study, the goal programming method was used to achieve the goals. The desired goals include increasing gross margin, reducing fertilizer consumption, increasing calorie and nutrient production, increasing total production and increasing oil production. It is important to note that the limiting inputs considered include land, water, and capital. The crops studied are also irrigated and include Tarom paddy rice, Shirodi paddy rice, wheat, rapeseed, barley, and soybeans. The required data is related to the agricultural year 2021-2022, which was collected by referring to the agricultural service center of the investigated sector and also the website of the Ministry of Agricultural Jihad. GAMS software was used to solve the ideal model.
Results and Discussion: The results indicate that considering all the above-mentioned ideals, the cultivation area of Tarom paddy rice, wheat, rapeseed and soybean has increased compared to the current cropping pattern, while it is suggested that the cultivation area of Shirodi paddy rice should be reduced. However, comparing the optimal cropping pattern in the studied scenarios with the current cropping pattern showed that the optimal cropping pattern is close to the current cultivation pattern. In other words, the farmers of the Rudpey District operate almost optimally. This result is more in terms of fertilizer consumption and profit achievement, so that the proposed cropping pattern has reduced fertilizer consumption by one percent and increased profit by a maximum of two percent. In other words, it can be said that farmers implement an economically appropriate cultivation pattern in the region, and the changes in the optimal cropping pattern compared to the current pattern were probably due to the objectives of oil and calorie production, so that the proposed cropping pattern leads to an 8 percent increase in oil production and an increase of about 3 percent in calorie production.
Conclusion: The results of this study showed that in the Rudpey District of Sari County, the existing cropping pattern of the region is not an optimal pattern in terms of achieving the goals of maximizing profit, maximizing calories and micronutrients, maximizing oil production, and minimizing chemical fertilizer consumption, but it is close to the optimal cultivation pattern. In fact, it can be said that in terms of achieving profit, the current cropping pattern of farmers in the studied region is not much different from the optimal pattern. In fact, despite the lack of sufficient knowledge, farmers implement an almost appropriate cultivation pattern in the region due to their experimental skills. The highest percentage of cultivation changes was related to barley and rice crops, and by assigning a higher weight to profit, soybean cultivation also experienced noticeable changes. Considering that one of the important goals in this study was an 8% increase in oil production, based on the results, this goal can be achieved by changing the share of rapeseed and soybean cultivation.
According to the results of this study, increasing the cultivation level of Tarom paddy rice and wheat compared to other crops can be in line with providing food for the community. Therefore, developing the cultivation of these crops in the Rudpey District of Sari County is recommended due to their special role in providing food for the community. On the other hand, developing oilseed cultivation requires giving up a portion of the profit, which requires the government to provide incentives and subsidies to make the production of these products more economical in order to develop the cultivation of these products and reduce dependence on imports.